domestic and wild animals. Occurs when a person develops the territory of the software. Foci of Japanese encephalitis, cutaneous leishmaniasis, tick-borne relapsing fever, etc. can acquire this character.
Synanthropic foci. The circulation of pathogens is associated only with domestic animals. Foci of toxoplasmosis, trichinosis.
2. By the number of owners
Polygostal. The reservoir is several species of animals (gophers, marmots, tarbagans, gerbils in the natural focus of the plague).
3. By the number of carriers
Monovector. Pathogens are transmitted by only one type of vector. It is determined by the species composition of vectors in a specific biocenosis (only one species of ixodid ticks lives in a certain focus of taiga encephalitis).
Polyvector. Pathogens are transmitted by various types of vectors. (For tularemia - carriers: various types of mosquitoes, horse flies, ixodid ticks).
Epidemics
Manifestations of the epidemic process by territory
It is worth noting that diseases are characteristic mainly of wild animals, but urbanization creates conditions for the spread of pathogens of these diseases among synanthropic animals and humans. This is how anthropurgic and then synanthropic foci of diseases arise, which can pose a significant epidemiological danger.
The term pandemic is used to describe an unusually intense epidemic affecting a number of countries.
Vector-borne diseases are infectious diseases transmitted by blood-sucking insects and arthropods. Infection occurs when a person or animal is bitten by an infected insect or tick.
About two hundred official diseases are known that have a vector-borne transmission route. They can be caused by various infectious agents: bacteria and viruses, protozoa and rickettsia *, and even helminths. Some of them are transmitted through the bite of blood-sucking arthropods (malaria, typhus, yellow fever), some of them are transmitted indirectly, when cutting the carcass of an infected animal, in turn, bitten by an insect carrier (plague, tularemia, anthrax). Such diseases are divided into two groups:
Obligately vector-borne diseases are vector-borne diseases that are transmitted only with the participation of a carrier.
Japanese encephalitis;
Typhus (lousy and tick-borne) typhus;
Relapsing (lousy and tick-borne) typhus;
Lyme disease, etc.
_________________________________________________
Facultatively vector-borne diseases are vector-borne diseases that spread in various ways, including with the participation of vectors.
Brucellosis;
Tick-borne encephalitis;
Anthrax;
Tularemia, etc.
Vector classification:
Specific carriers ensure the transfer of pathogens from the blood
sick animals or humans into the blood of healthy ones. In the body
specific carriers, the pathogen multiplies or accumulates. In this way, fleas transmit plague, lice - typhus, mosquitoes - Papatachi fever. In the body of some carriers, the pathogen goes through a certain development cycle. Thus, in the body of a mosquito of the genus Anopheles, malaria plasmodium completes the sexual development cycle. Along with this, in the body of ticks, the causative agents of tick-borne encephalitis and some rickettsial diseases not only multiply and accumulate, but are also transmitted to a new generation through the egg (transovarial). Therefore, the pathogen in the body of a specific carrier can persist (with some exceptions) throughout the life of the carrier;
Nonspecific (mechanical) carriers that perform
mechanical transfer of the causative agent of the disease without its development and reproduction (horseflies, autumn flies and ixodid ticks for the causative agents of tularemia, brucellosis, anthrax).
Transmissible diseases are also divided into two groups depending on the pathogen:
Invasions (pathogens are animals);
Infections (causative agents - viruses, rickettsia and bacteria).
Faculty: Pharmaceutical.
Department: Biology.
SCIENTIFIC WORK
Performer: Mamedova Jamilya Subkhanovna.
Scientific supervisor: Sobenina Galina Grigorievna.
Chelyabinsk
4. Infectious diseases
References
1. Vector-borne diseases
Vector-borne animal diseases are characterized by enzootic nature (confined to a specific area, climatic-geographical zone) and seasonality of manifestation. In cases where pathogens are transmitted by flying insects, vector-borne animal diseases usually spread more widely than when the pathogen is transmitted by ticks. Obligate vector-borne diseases of animals include: infectious bluetongue of sheep, hydropericarditis, infectious encephalomyelitis and infectious anemia of horses, African horse sickness, Rift Valley fever, Nairobi disease, Scottish sheep encephalomyelitis, viral nodular dermatitis; optional - anthrax, African swine fever, tularemia and other septic infections. Prevention measures include protecting humans and animals from attacks by blood-sucking arthropods (change of grazing, transfer to stall housing, use of repellents), destruction of vectors and rodents, reclamation measures in breeding areas of vectors, immunization of humans and animals (if developed).
2. Natural focal diseases
Natural focal diseases are an infectious disease, the causative agent of which constantly circulates among certain species of wild animals (birds and mammals are of greatest importance for humans and domestic animals), spreading by arthropod carriers (vector-borne diseases) or through direct contact, bites, etc. Natural focal diseases are transmitted to people and domestic animals by the same carriers, but sometimes through water and food. Naturally focal human diseases include plague, tularemia, tick-borne and mosquito-borne (Japanese) encephalitis, rabies, leptospirosis, hemorrhagic fevers, cutaneous leishmaniasis, tick-borne typhus, some types of helminthiasis (diphyllobothriasis, alveococcosis, echinococcosis, etc.). Some of these diseases are characteristic of domestic animals (rabies, leptospirosis, glanders, foot and mouth disease). For the first time, the idea of natural foci of animal and human diseases was introduced by D.N. Zabolotny in 1899. The connection between these foci and landscapes was formulated by N.A. Gaisky in 1931. Subsequently, the doctrine of natural focality was developed by E.N. Pavlovsky and his school using the example of various diseases (plague - V.V. Kucheruk, tularemia - N.G. Olsufiev, tick-borne encephalitis - N.B. Birulei, etc.). The size of the outbreak depends on the type of pathogen, the natural environment and the social and living conditions of the population. In typhus, dysentery, and scarlet fever, the source of infection is the patient’s apartment or home. In malaria, the outbreak covers an area within which the disease can be transmitted by mosquitoes contracted on a given patient. As for the relationship between the territory of the outbreak and natural-territorial complexes of various ranks, the smallest territorial unit with which the outbreak of the disease can be associated is the landscape, which represents a genetically isolated part of the landscape envelope. Smaller in size and simpler in structure morphological parts of the landscape (tracts, facies), apparently, do not possess all the qualities necessary for the long-term existence of the pathogen population. However, a complete analogy cannot be drawn between the division of the biosphere into natural-territorial complexes and the identification of disease foci. The landscape area is limited to the foci of many diseases (cutaneous leishmaniasis, tick-borne spirochetosis). The outbreaks of others (plague, etc.) cover an entire landscape area. The foci of diseases have a certain structure.
There are three types of morphological parts or elements of the focus: areas of relatively persistent infection (nucleus of the focus); areas of infection; areas that are constantly free from infectious agents. Depending on how pronounced the differences are between the morphological parts of the lesion, three types of its structure are distinguished: homogeneous (diffuse, homogeneous), heterogeneous (heterogeneous) and sharply heterogeneous (sharply heterogeneous). In diffuse outbreaks, the pathogen is scattered throughout the entire territory of the outbreak, and the danger of infection threatens a person when he is located at almost any point of the outbreak. In heterogeneous foci, the maximum risk of infection is associated with staying in areas of relatively persistent infection. The geographical features of the distribution of outbreaks are determined by their location in the landscapes of different zones. Zonal natural foci (associated with the upland conditions of a particular zone) have tick-borne encephalitis (southern part of the forest zone), plague (arid zones - steppe, desert, as well as corresponding arid mountain belts), tick-borne spirochetosis (desert zone), southern leishmaniasis (desert zone), yellow fever (equatorial and tropical rain forest zone), etc. Intrazonal foci that do not occupy placors in any zone, occurring in several zones, are characteristic of tularemia, mosquito encephalitis and other diseases. Outside of “their” zone, many diseases that have zonal foci transform into extrazonal conditions. Thus, the limestone outcrops of the river valleys of Southern Ukraine are characterized by foci of tick-borne spirochetosis, the birch forests of the Kustanai region - foci of tick-borne encephalitis, etc. Human impact contributes to the expansion of the territory of the outbreaks and their removal beyond the limits of their natural conditions. Thus, Q fever, whose natural foci are associated with arid zones, can affect domestic animals far beyond their borders, for example, in a forest zone; plague carried by rats has in past centuries affected cities located in a wide variety of environmental conditions, etc. A.G. Voronov (1981) proposes to introduce three categories of outbreaks according to the degree of change in natural conditions by humans:
Foci of man-made natural-territorial and natural-technogenic-territorial complexes: a) settlements and buildings; b) “industrial” landscapes (dumps, waste heaps; c) fields and vegetable gardens; d) plantations, gardens and parks; e) sown meadows, forest plantings, canals, reservoirs, reclaimed lands, which have analogues among indigenous communities.
Foci of natural-territorial complexes transformed by man; f) rapidly recovering communities of clearings, fallows, etc. g) long-term continental meadows, small-leaved forests, secondary savannas.
Foci of indigenous natural-territorial complexes, not changed or slightly changed by human activity. Prevention of natural focal diseases consists of immunizing people and domestic animals, repelling and destroying vectors and natural carriers of diseases, using protective equipment and other measures.
Helminths cause helminthiasis, of which the most common are ascariasis, hookworm disease, hymenolepiasis, diphyllobothriasis, taeniasis, trichinosis, trichocephalosis, enterobiasis, echinococcosis, etc.
Prevention
On the scale of a specific person:
improving the health of young women and men before marriage can save them from much suffering due to the birth of sick children;
Don't be ignorant about personal health issues.
4. Infectious diseases
Infectious diseases are a group of diseases that are caused by specific pathogens and are characterized by contagiousness, a cyclical course and the formation of post-infectious immunity. The term "infectious diseases" was introduced by Gufeland and gained international currency. It is also used to designate the field of clinical medicine, which studies the pathogenesis, clinical picture of infectious diseases and develops methods for their diagnosis and treatment.
Classification.
Due to the diversity of biological properties of infectious agents, mechanisms of their transmission, pathogenetic features and clinical manifestations of infectious diseases, classifying the latter according to a single criterion is very difficult. The most widespread classification was theoretically substantiated by L.V. Gromashevsky, which is based on the mechanism of transmission of the infectious agent and its localization in the body. Under natural conditions, there are four types of transmission mechanisms: fecal-oral (for intestinal infections), aspiration (for respiratory tract infections), transmissible (for blood infections) and contact (for infections of the outer integument). The transmission mechanism in most cases determines the preferential localization of the pathogen in the body. In intestinal infections, the pathogen is mainly localized in the intestine throughout the entire illness or during certain periods; for respiratory tract infections - in the mucous membranes of the pharynx, trachea, bronchi and alveoli, where the inflammatory process develops; for blood infections - circulates in the blood and lymphatic system; with infections of the external integument (this also includes wound infections), the skin and mucous membranes are primarily affected. Depending on the main source of the causative agent, infectious diseases are divided into anthroponoses (the source of pathogens is humans) and zoonoses (the source of pathogens is animals).
Some infectious diseases, in addition to the main transmission mechanism that determines their group affiliation, also have another mechanism of pathogen transmission. This leads to the fact that the disease can manifest itself in different clinical forms, corresponding to the mechanism of transmission. Thus, tularemia in humans most often occurs in the bubonic form, but when the pathogen is transmitted through airborne dust, a pulmonary form of the disease develops.
Not all infectious diseases can be classified with sufficient confidence into one group or another (for example, polio, leprosy, tularemia). However, the value of the classification of L.V. Gromashevsky is that as knowledge about the nature of insufficiently studied diseases deepens, they find an appropriate place in it.
) intestinal infections;
) tuberculosis;
) bacterial zoonoses;
) other bacterial diseases;
) polio and other viral diseases c. n. pp., not transmitted by arthropods;
) viral diseases accompanied by rashes;
) viral diseases transmitted by arthropods;
) other diseases caused by viruses and chlamydia;
) rickettsioses and other diseases transmitted by arthropods;
) syphilis and other sexually transmitted diseases;
) other diseases caused by spirochetes;
However, some deviations from the International Classification of Diseases are allowed. Thus, influenza and other acute respiratory viral infections are classified as infectious diseases (first class group), and in the International Classification of Diseases they are included among respiratory diseases.
Etiology and pathogenesis.
The direct cause of infectious diseases is the introduction of pathogenic agents into the human body (sometimes the ingestion of their toxins, mainly with food), with the cells and tissues of which they interact.
The pathogenesis of infectious diseases reflects the main stages of development of the infectious process: introduction and adaptation of the pathogen, its reproduction, breakthrough of protective barriers and generalization of infection, damage to organs and tissues, disruption of their function, the appearance of nonspecific protective reactions (Fever), inflammation (Inflammation), sensitization of the body by components microbial cell, the formation of specific Immunity, cleansing the body of the pathogen, reparation of damaged organs and tissues and restoration of their function. However, not all infectious diseases reveal all stages and links of pathogenesis; their significance in the pathogenesis of one or another nosological form is also different. For example, with tetanus and botulism, the pathogen does not penetrate local protective barriers, and the clinical manifestations of the disease are caused by the action of absorbed toxins. The role of the allergic component is also different. In erysipelas, scarlet fever, brucellosis, and typhoid fever, it plays an important role in the pathogenesis and clinical manifestations of the disease; in dysentery and cholera its role is not significant. The emerging immunity can be long-term and durable (for example, with typhoid fever, viral hepatitis A, smallpox, measles) or short-term (for example, with influenza, dysentery). In some cases, immunity is defective, which can manifest itself in relapses, protracted and chronic course of the infectious process. Finally, with some diseases (for example, erysipelas), immunity is not formed. In a number of infectious diseases, immunopathology develops, leading to a chronic course of the process (viral hepatitis B, slow infections of the nervous system). In the development of the chronic course of the disease, an important role is played by changes in the properties of the pathogen in the process of infectious diseases, in particular its L-transformation.
Circulation of the pathogen and its toxins, disruption of the functional state of organs. tissue damage, accumulation of metabolic products, cellular and tissue decay lead to the development of the most important clinical manifestation of infectious diseases - intoxication (Intoxication).
Restorative and reparative processes after an infectious disease are not always sufficiently complete, therefore post-infectious chronic diseases and pathological conditions often develop, for example, chronic colitis after dysentery, chronic nonspecific lung diseases after repeated acute respiratory viral infections, myocardiosclerosis after infectious myocarditis, joint contractures after brucellosis, intracranial hypertension after bacterial or viral meningitis.
Pathological anatomy.
Basic information about pathological anatomy was obtained on the basis of autopsy data, study of biopsy material and the results of endoscopic studies. These data indicate a wide range of morphological changes in tissues and organs. Some of them are nonspecific, others are specific both in the nature of changes in tissues and organs and in the localization of the pathological process.
For example, dysentery is characterized by damage to the rest of the colon, typhoid fever - the distal part of the small intestine, infectious mononucleosis - damage to the lymphoid apparatus, and meningitis - inflammatory damage to the meninges. A number of infectious diseases are characterized by the presence of specific inflammatory granulomas (epidemic typhus, tuberculosis). Many morphological changes are caused by the addition of complications (for example, pneumonia with influenza).
Clinical picture.
Most infectious diseases are characterized by cyclical development, i.e. a certain sequence of appearance, increase and disappearance of symptoms. for example, the appearance of jaundice in viral hepatitis is preceded by a pre-icteric (prodromal) period, a rash in epidemic typhus appears on the 4-6th day of illness, in typhoid fever - on the 8-10th day of illness. With food poisoning, vomiting appears first, then diarrhea; with cholera, it’s the opposite.
There are the following periods of disease development: incubation (latent), prodromal (initial), main manifestations of the disease, extinction of disease symptoms (early period of convalescence), recovery (convalescence).
Incubation period is the period of time from the moment of infection until the appearance of the first wedges. symptoms of the disease.
The prodromal, or initial, period is accompanied by general manifestations of infectious diseases: malaise, often chills, fever, headache, sometimes nausea, minor muscle and joint pain, i.e. signs of a disease that do not have any clear specific manifestations. The prodromal period is not observed in all infectious diseases; it usually lasts 1-2 days.
The period of the main manifestations of the disease is characterized by the occurrence of the most significant and specific symptoms of the disease, morphological and biochemical changes. During the period of the main manifestations of the disease, the patient’s death may occur, or the disease may progress to the next period.
The period of extinction of the disease is characterized by the gradual disappearance of the main symptoms. Normalization of temperature can occur gradually (lysis) or very quickly, within several hours (crisis). The crisis, often observed in patients with typhus, epidemic and relapsing fever, is often accompanied by significant dysfunction of the cardiovascular system and profuse sweating.
The period of convalescence begins with the extinction of clinical symptoms. Its duration varies widely even for the same disease and depends on the form of the disease, severity, immunological characteristics of the body, and the effectiveness of treatment. Clinical recovery almost never coincides with complete morphological restoration of damage, which often lasts for a longer time.
Recovery can be complete when all impaired functions are restored, or incomplete if residual effects persist.
In addition to exacerbations and relapses, complications can develop during any period of infectious diseases, which can be divided into specific and nonspecific. Specific complications arise as a result of the action of the causative agent of this infectious disease and are a consequence of either the unusual severity of typical clinical and morphological manifestations of the disease (perforation of intestinal ulcers in typhoid fever, hepatic coma in viral hepatitis), or atypical localization of tissue damage (for example, Salmonella endocarditis, otitis media in typhoid fever). Complications caused by microorganisms of another type are usually called secondary infections, viral or bacterial superinfections. Reinfections, which are repeated diseases that occur after repeated infection with the same pathogen, should be distinguished from the latter.
There are also early and late complications. Early ones develop during the period of the height of the disease, late ones - during the period of extinction of its symptoms.
Depending on the characteristics, various clinical forms of infectious diseases are distinguished. According to the duration, acute, protracted, subacute and chronic course of the disease is distinguished, and in the latter case it can be continuous and recurrent. According to the severity of the course, mild, moderate, severe and very severe forms of the disease are possible, and the degree of severity is determined both by the severity of specific symptoms and by intoxication, damage to vital organs and the presence of complications. With some I. b. There are also hypertoxic, fulminant (fulminant) forms of the disease, reflecting the extremely rapid development of the pathological process and its severe course. Depending on the presence and severity of characteristic symptoms, it is customary to distinguish between typical and atypical course of the disease. With an atypical course of an infectious disease, the clinical picture is dominated by symptoms that are not characteristic of this disease, for example, with typhoid fever, the symptoms of pneumonia (“pneumotyphoid”) predominate, or the most important symptoms are absent, for example, with meningitis - meningeal syndrome. Atypical forms of infectious diseases also include the abortive course of the disease (the disease ends before the appearance of typical symptoms, for example, typhoid fever in vaccinated people) and the erased course of the disease (the general clinical manifestations of the disease are mild and short-lived, and there are no characteristic symptoms), for example, with the erased course of polio There is only a slight fever and mild catarrhal symptoms, and there are no signs of damage to the nervous system.
The most characteristic manifestations of infectious diseases are fever and intoxication. The presence of fever is typical for the vast majority of infectious diseases, with the exception of cholera, botulism and some others. Fever may be absent with a mild and abortive course of the disease. Many infectious diseases are characterized by certain types of febrile reactions; brucellosis - remitting, many spirochetosis - relapsing type, etc. Intoxication is manifested by weakness, decreased performance, anorexia, sleep disturbances, headache, vomiting, delirium, disturbances of consciousness, meningeal syndrome, pain in muscles, joints, tachycardia, arterial hypotension.
A large group of infectious diseases is characterized by the presence of a rash (exanthema), and the timing of its appearance, localization, morphology, and metamorphosis are typical for the corresponding infectious disease. Less common are rashes on the mucous membranes (enanthema) of the eyes, pharynx, pharynx, and genitals. In a number of vector-borne infectious diseases, inflammatory changes are observed at the site of penetration of the pathogen into the skin - a primary affect that may precede other clinical symptoms of the disease. Symptoms observed in a number of infectious diseases include damage to the lymphatic system in the form of an enlargement of individual groups of lymph nodes (lymphadenitis) or a generalized enlargement of three or more groups of lymph nodes (polyadenitis). Joint damage in the form of mono-, poly- and periarthritis is characteristic of relatively few infectious diseases - brucellosis, pseudotuberculosis, meningococcal infection and some others. The main clinical manifestation of acute respiratory viral infections is catarrhal respiratory syndrome, which is characterized by coughing, sneezing, runny nose, pain and sore throat. Specific pneumonias are observed less frequently (for example, with psittacosis, legionellosis, Q fever, mycoplasmosis). Changes in the cardiovascular system mainly reflect the severity of intoxication and the severity of the disease, however, in some infectious diseases, damage to the heart (for example, diphtheria) or blood vessels (with hemorrhagic fevers, epidemic typhus, meningococcal infection) are characteristic manifestations of the disease. Dyspeptic disorders (abdominal pain, diarrhea, vomiting, loss of appetite) are the most typical symptom of acute intestinal infections; Moreover, for different intestinal infections, their manifestations differ significantly. Thus, the gastrointestinal form of salmonellosis is characterized by epigastric pain and frequent vomiting; with dysentery, pain is localized in the left iliac region, and scanty mucous-bloody stool is characteristic. One of the important manifestations of many infectious diseases in which circulation of the pathogen in the blood is observed is hepatolienal syndrome - a combined enlargement of the liver and spleen (typhoid fever, epidemic typhus, viral hepatitis, infectious mononucleosis, brucellosis, tularemia, leptospirosis, etc.). Specific kidney damage is observed in leptospirosis, hemorrhagic fever with renal syndrome; genital organs - with brucellosis, mumps, and other infectious diseases it is rare.
An important place in the clinic of infectious diseases is occupied by c. n. With. nonspecific (intoxication), specific (toxic, for example, with tetanus, botulism) and inflammatory (for example, with meningitis, meningoencephalitis, encephalitis) nature. In this case, disturbances of consciousness, convulsive and meningeal syndrome, and focal symptoms of damage to the nervous system are observed. Specific lesions of the peripheral nervous system (neuritis, radiculitis, polyneuritis, polyradiculoneuritis) are usually observed during viral infections, but can also have a toxic origin (for example, diphtheria).
When examining infectious patients, significant changes are revealed in the blood picture, indicators of metabolic processes, protein, lipid, carbohydrate composition of plasma, metabolism of biologically active substances, which reflect various aspects of the pathogenesis of infectious diseases and their clinical manifestations.
The diagnosis is based on the patient's complaints, medical history, epidemiological history, results of examination of the patient, data from laboratory and instrumental studies. During the initial examination, a preliminary diagnosis is made, which determines further tactics of examination and implementation of anti-epidemic measures (isolation of the patient, identification of people with whom the patient communicated, possible sources of the infectious agent and the mechanism of transmission of infection). After receiving the results of the examination of the patient and taking into account epidemiological data, a final diagnosis is established. The diagnosis indicates the nosological form, the method of confirming the diagnosis, the severity and characteristics of the course of the disease, its period, the presence of complications and concomitant diseases. For example: "Typhoid fever (blood culture), severe course of the disease, peak period; complication - intestinal bleeding; concomitant disease - diabetes mellitus." The most accurately formulated and detailed diagnosis determines the therapeutic tactics.
In some cases, when clinical data is insufficient and laboratory tests do not allow establishing the etiology of the disease, a syndromic diagnosis is allowed (for example, foodborne illness, acute respiratory viral infection).
Treatment of patients with infectious diseases must be comprehensive and determined by diagnosis, i.e. based on the etiology, severity and other features of the course of the disease, the presence of complications and concomitant diseases, age and immunological characteristics of the patient’s body. At the same time, the scope of treatment measures, in order to avoid the simultaneous (often unjustified) prescription of multiple medications and treatment procedures and unpredictable side effects, should be limited to the minimum necessary in a particular case.
The basis of treatment is etiotropic therapy: the use of antibiotics and chemotherapy drugs, to the therapeutic concentrations of which the causative agents of the corresponding infectious diseases are sensitive. The sensitivity of a pathogen to a particular drug is a species property, so drugs are used based on the type of pathogen. Thus, for typhoid fever, chloramphenicol is prescribed, for meningococcal infection - benzyl penicillin, for rickettsiosis - tetracycline drugs, etc. However, due to the frequent drug resistance of a number of pathogens, for example staphylococcus, it is necessary to strive to isolate a culture of the pathogen, determine its antibiogram and, in the absence of a clinical effect from the therapy, carry out its correction. Etiotropic therapy should be started as early as possible and carried out taking into account the localization of the pathogen in the patient’s body, the characteristics of the pathogenesis of the disease, the patient’s age, the mechanism of action and pharmacokinetics of the drug. Based on these parameters, the daily dose, intervals between single doses, route of administration and duration of treatment are determined. Due to the fact that antibiotics and chemotherapy drugs have a number of side effects (toxicity, inhibition of immunogenesis, reparative processes, sensitizing effects, development of dysbacteriosis), they must be used strictly according to indications. Thus, treatment should not be started before a diagnosis is made or before material is taken for bacteriological examination, in case of uncomplicated course of viral infectious diseases (influenza, acute respiratory viral infection, viral meningitis, etc.), in case of mild course of some bacterial infections (for example, dysentery), in the presence of individual intolerance. Only in some cases of severe infectious diseases in a hospital setting is it advisable to use etiotropic drugs until the diagnosis is clarified.
The second important area of treatment of infectious diseases is immunotherapy, which is divided into specific and nonspecific. Antitoxic serums (antitetanus, antibotulinum, antidiphtheria, etc.) and γ- globulins, as well as antimicrobial serums and γ- globulins (anti-influenza, anti-measles, anti-staphylococcal, etc.). Plasma from immunized donors (antistaphylococcal, antipseudomonas, etc.) is also used. These drugs contain ready-made antibodies against toxins and the pathogen itself, i.e. create passive immunity. Vaccine preparations (toxoids, corpuscular killed vaccines) are also used for therapeutic purposes. As a specific method of treatment, attempts were made to phage therapy, which turned out to be effective only in a number of cases of staphylococcal infection. Nonspecific immunotherapy includes the use of nonspecific immunoglobulin preparations (normal human immunoglobulin, polyoglobulin), as well as drugs that affect the body’s immune system (immunostimulants, immunomodulators, immunosuppressors), for example T - and B-activin, levamisole, sodium nucleinate, pentoxyl, methyluracil, corticosteroids, etc. In the treatment of severe forms of infectious diseases, pathogenetic syndromic therapy occupies an important place, including the use of intensive care and resuscitation methods. Detoxification is of great importance, which is carried out by administering colloid and crystalloid solutions while simultaneously forcing diuresis with saluretics. In severe cases, extracorporeal detoxification methods are used - plasmapheresis, hemosorption, hemodialysis. In the presence of dehydration syndrome, rehydration therapy is carried out. Complex pathogenetic therapy is indicated for the development of infectious-toxic shock, thrombohemorrhagic syndrome, cerebral edema, convulsive syndrome, acute respiratory failure, cardiovascular failure, and severe organ failure. In these cases, methods such as artificial ventilation, Hyperbaric oxygenation, etc. are used. Drugs are used that affect individual pathogenetic mechanisms of infectious diseases, for example, for hyperthermia - antipyretics, for diarrhea - prostaglandin synthesis inhibitors, for allergies - antihistamines, etc. A rational, nutritious diet enriched with vitamins is of great importance. When prescribing a diet, the pathogenesis of the disease is taken into account. So, for dysentery - a colitis diet, for viral hepatitis - a hepatic diet. In severe cases, when patients cannot eat food on their own (coma, paresis of the swallowing muscles, profound disorders of absorption and digestion of food), tube feeding with special mixtures (enpits), parenteral nutrition and mixed enteral-parenteral nutrition are used. Compliance with the necessary regimen, care of the skin and mucous membranes, control of physiological functions are also important for the outcome of the disease. Physiotherapy and balneotherapy methods are used according to individual indications, and sanatorium-resort treatment is used to treat residual effects. After a number of infectious diseases (for example, neuroinfections, viral hepatitis, brucellosis), patients are monitored at the dispensary until complete recovery and labor rehabilitation. In some cases, a disability group is established as a temporary measure; in rare cases, permanent disability is observed. The prognosis for the vast majority of infectious diseases is favorable. However, with untimely diagnosis and incorrect therapeutic tactics, an unfavorable outcome, recovery with residual effects and adverse long-term consequences are possible. In some cases, an unfavorable outcome in infectious diseases may be due to the fulminant course of the disease (for example, meningococcal infection), as well as the lack of effective treatment methods (for example, for HIV infection, hemorrhagic fevers and some other viral diseases). Prevention. Measures to combat infectious diseases are divided into sanitary and preventive measures, carried out regardless of the presence of infectious diseases, and anti-epidemic measures, which are carried out when infectious diseases occur. Both groups of measures are carried out in three directions: neutralization, elimination (isolation) of the source of the infectious agent, and in case of zoonoses, also neutralization of the source of the infectious agent or reduction in numbers or destruction, for example, of rodents; suppression of the mechanism of transmission of the infectious agent, impact on the pathways and factors of transmission of pathogens; creating immunity of the population to this infectious disease. The structure of a natural hearth. The main components of the outbreak are: ) pathogen ) animal reservoirs ) carrier ) "receptacle of the hearth" in spatial terms ) the presence of environmental factors favorable to the existence of biotic elements of the focus and circulation of the pathogen of the corresponding zoonosis. In the presence of all these components, a zoonotic autochthonous outbreak, potentially dangerous to humans, flourishes in nature. Its epidemiological significance manifests itself when a person susceptible to the corresponding disease appears in its zone of influence (“anthropurgic factor”). This category of natural foci includes: tick-borne encephalitis, many tick-borne typhus fevers, tularemia, plague, Pendinsky ulcer of the semi-desert zone (marine form), yellow jungle fever, probably Japanese encephalitis in natural conditions, etc. Their antipode is physioanthropic foci, characterized by the fact that the causative agent of the disease nesting in them is characteristic exclusively of humans and specific carriers; Consequently, animal reservoirs are completely excluded from the number of “constituents” of the focus. An example is malaria, maybe papatachi fever (if the assumption of its natural focality is not justified). Physioanthropic foci arise either on a natural basis or in the immediate environment of a person (up to intra-household infection). In the first case, specific carriers (anopheles mosquitoes) nest in nature, but with regard to the malaria pathogen they are sterile, because there is no source of its production in nature. “The hearth receptacle” is diffuse; this is the zone used by winged anopheles (reservoirs where they hatch). When gamete carriers enter such a zone, they carry the malaria pathogen and attract malaria mosquitoes as a new source of blood feeding. In the process of blood-sucking, mosquitoes acquire malarial plasmodia and, in the presence of favorable environmental factors (mainly temperature), reach an invasive state in which they can transmit malaria to people. In the case considered, anthropurgic factors come down to the appearance of gamete carriers and people susceptible to infection in a natural area inhabited by malaria mosquitoes, and to the failure to take measures to combat and prevent malaria. However, physioanthropic foci of malaria can be created predominantly on an anthropurgic basis; An excellent example is given by the picture of the movement of malaria into the Karakum Desert during the flooding of the Kolifa Uzboy; humans created new sources of reproduction of Anopheles mosquitoes. moving deeper and deeper into the desert (creation - “container of the hearth”) due to the passive introduction of mosquito larvae among fragments of plants with incoming water; mosquitoes appeared already in the first year of the beginning of flooding, when water flowed along Uzboy for only 50 km. Malaria also began to affect workers. Anopheles fed on the blood of not only people, but also wild animals (goitered gazelles, rodents, etc.) and found shelter from the heat of the day in rodent burrows, human habitation, and reed thickets (Petrishcheva, 1936). An example of physianthropic foci that exist on an anthropurgic basis is papatachi fever in cities and villages. Zoonotic foci, in turn, can be modified by human activity. The causative agent of the disease can enter a newly formed focus in the body of an arriving person or animal reservoir of the virus. These animals, as well as their carriers, can move from life in nature to living in human habitation and services; in the presence of a favorable macro- and microclimate of the biotopes inhabited by carriers, and when there are people susceptible to infection there, the latter become ill at home with a disease that has its roots in natural foci (tick-borne relapsing fever, yellow fever, pendinka in cities). Nobel Prize winner scientist Zhores Alferov said in one of his television interviews: “The future of all science lies in quantum physics.” The synthesis of her achievements and ancient Eastern acupuncture gave the world an ingenious diagnostic method, which has not yet been properly appreciated by society, and even more so has not yet been properly implemented in practical healthcare. According to the theory of Chinese acupuncture, all internal organs of the human body are energetically projected onto certain points on the hands and feet. The German doctor R. Voll invented a device with an arrow on which it is possible to measure electrical conductivity at these points - according to the indication of the arrow of the device, one can judge the condition of the organ for which the point under study is responsible (acute inflammation, normal, chronic process, etc.) Particular attention should be paid to the issue of coincidence, or rather, discrepancy, between the results of the examination based on the Voll method and generally accepted laboratory tests. The lack of information in laboratory stool tests for helminth and protozoan eggs is known to everyone; it is almost always written that they were not detected, whereas there are clear signs of their presence. As for more complex tests - immunological methods for studying blood, there is nothing comforting here either. At the latest scientific and practical symposium “Gene diagnostic technologies in practical healthcare”, which you can believe or not believe; this is an already existing reality in medicine - this parallel science has its own discoveries, scientific journals, scientific congresses and conferences are regularly convened, dissertations are defended. There is also a special Government Decree No. 211 of June 6, 1989, which gives the right to introduce the Voll method, one of the methods of energy-information diagnostics and therapy, into clinical practice. In the middle of the 12th century, Redi experimentally proved for the first time that flies and gadflies develop from eggs, which dealt a blow to the theory of spontaneous generation of organisms. The invention of the microscope by the Dutch researcher Leeuwenhoek in the 17th century. ushered in a new era in the history of biology. Academician K.I. Scriabin created a helminthological school, uniting veterinary, medical, biological and agronomic specialists. This school successfully studies helminths and the diseases they cause - helminthiasis, develops and implements measures to combat them, up to devastation (complete destruction). By specialty K.I. Scriabin is a veterinarian. For his great services in the development of helminthology, he was awarded the title of Hero of Socialist Labor, laureate of the Lenin and two State Prizes, awarded 11 orders, and was elected to actual captivity. Academy of Sciences of the USSR, Academy of Medical Sciences and All-Union Academy of Agricultural Sciences named after V.I. Lenin (VASKHNIL).K.I. Scriabin wrote over 700 scientific works, including many monographs and several textbooks. References
1.Biology N.V. Chebyshev, G.G. Grineva, M.V. Kozar, S.I. Gulenkov. Edited by acad. RAO, professor N.V. Chebysheva Moscow. GOU VUNMC 2005 2.Biology with general genetics. A.A. Slyusarev. Moscow. "Medicine" 1978 .Biology. Edited by Academician of the Russian Academy of Medical Sciences Professor V.N. Yarygina. In two volumes. Book 1. Moscow "Higher School" 2000 .Biology. Edited by Academician of the Russian Academy of Medical Sciences Professor V.N. Yarygina. In two volumes. Book 2. Moscow "Higher School" 2000 .Medical genetics. Under the reaction of N.P. Bochkova. Moscow. ACADEMA. 2003
Vector-borne diseases are infectious diseases transmitted by blood-sucking insects and arthropods. Infection occurs when a person or animal is bitten by an infected insect or tick.
About two hundred official diseases are known that have a vector-borne transmission route. They can be caused by various infectious agents: bacteria and viruses, protozoa and rickettsia, and even helminths. Some of them are transmitted through the bite of blood-sucking arthropods (malaria, typhus, yellow fever), some of them are transmitted indirectly, when cutting the carcass of an infected animal, in turn, bitten by an insect carrier (plague, tularemia, anthrax).
Vectors
The pathogen passes through a mechanical carrier in transit (without development or reproduction). It can persist for some time on the proboscis, body surface or in the digestive tract of the arthropod. If at this time a bite occurs or contact with the wound surface occurs, the person will become infected. A typical representative of a mechanical vector is the fly of the family. Muscidae. This insect carries a wide variety of pathogens: bacteria, viruses, protozoa.
As already indicated, according to the method of transmission of the pathogen by an arthropod vector from an infected vertebrate donor to a vertebrate recipient, natural focal diseases are divided into 2 types:
obligate-transmissible, in which the pathogen is transmitted from a donor vertebrate to a recipient vertebrate only through a blood-sucking arthropod during blood sucking;
optional-transmission natural focal diseases in which the participation of a blood-sucking arthropod (vector) in the transmission of the pathogen is possible, but not necessary. In other words, along with transmissible (through a bloodsucker), there are other ways of transmitting the pathogen from a donor vertebrate to a recipient vertebrate and to humans (for example, oral, nutritional, contact, etc.).
According to E. N. Pavlovsky (Fig. 1.1), the phenomenon natural focality vector-borne diseases is that, regardless of humans, on the territory of certain geographical landscapes there can be outbreaks diseases to which a person is susceptible.
Such foci were formed in the process of long-term evolution of biocenoses with the inclusion of three main links in their composition:
Populations pathogens illness;
Wildlife populations - natural reservoir hosts(donors and recipients);
Populations of blood-sucking arthropods - carriers of pathogens diseases.
It should be borne in mind that each population of both natural reservoirs (wild animals) and vectors (arthropods) occupies a certain territory with a specific geographical landscape, due to which each focus of infection (invasion) occupies a certain territory.
In this regard, for the existence of a natural focus of the disease, along with the three links mentioned above (pathogen, natural reservoir and vector), the fourth link is also of utmost importance:
natural landscape(taiga, mixed forests, steppes, semi-deserts, deserts, various bodies of water, etc.).
Within the same geographical landscape, there may be natural foci of several diseases, which are called conjugated. This is important to know when vaccinating.
Under favorable environmental conditions, the circulation of pathogens between vectors and animals - natural reservoirs - can occur indefinitely. In some cases, infection of animals leads to their illness, in others there is asymptomatic carriage.
By origin natural focal diseases are typical zoonoses, i.e., circulation of the pathogen occurs only between wild vertebrates, but it is possible that foci may exist for anthropozoonotic infections.
According to E. N. Pavlovsky, natural foci of vector-borne diseases are monovector, if in
transmission of the pathogen involves one type of carrier (louse-borne relapsing fever and typhus), and multi-vector, if transmission of the same type of pathogen occurs through vectors of two, three or more species of arthropods. The majority of foci of such diseases (encephalitis - taiga, or early spring, and Japanese, or summer-autumn; spirochetosis - tick-borne relapsing fever; rickettsiosis - North Asian tick-borne typhus, etc.).
The doctrine of natural focality indicates the unequal epidemiological significance of the entire territory of the natural focus of the disease due to the concentration of infected vectors only in certain microstations. Such a center becomes diffuse.
In connection with general economic or purposeful human activity and the expansion of urbanized territories, humanity has created conditions for the mass spread of the so-called synanthropic animals (cockroaches, bedbugs, rats, house mice, some ticks and other arthropods). As a result, humanity is faced with an unprecedented phenomenon of the formation anthropogenic foci of diseases, which can sometimes become even more dangerous than natural foci.
Due to human economic activity, it is possible for the old focus of the disease to irradiate (spread) to new places if they have favorable conditions for the habitat of carriers and animals - donors of the pathogen (construction of reservoirs, rice fields, etc.).
Meanwhile, it is not excluded destruction(destruction) of natural foci when its members that take part in the circulation of the pathogen fall out of the biocenosis (during the drainage of swamps and lakes, deforestation).
In some natural foci there may be an ecological succession(replacement of one biocenosis by another) when new components of the biocenosis appear in them, capable of being included in the pathogen circulation chain. For example, the acclimatization of the muskrat in natural foci of tularemia led to the inclusion of this animal in the circulation chain of the disease pathogen.
E. N. Pavlovsky (1946) identifies a special group of lesions - anthropourgic foci, the emergence and existence of which is associated with any type of human activity and also with the ability of many types of arthropods - inoculators (bloodsucking mosquitoes, ticks, mosquitoes that carry viruses, rickettsia, spirochetes and other pathogens) to synanthropic way of life. Such arthropod vectors live and breed in settlements of both rural and urban types. Anthropourgic foci arose secondarily; In addition to wild animals, the circulation of the pathogen includes domestic animals, including birds, and humans, so such outbreaks often become very intense. Thus, large outbreaks of Japanese encephalitis have been noted in Tokyo, Seoul, Singapore and other large settlements in Southeast Asia.
Foci of tick-borne relapsing fever, cutaneous leishmaniasis, trypanosomiasis, etc. can also acquire an anthropourgic character.
The stability of natural foci of some diseases is explained primarily by the continuous exchange of pathogens between carriers and animals - natural reservoirs (donors and recipients), but the circulation of pathogens (viruses, rickettsia, spirochetes, protozoa) in the peripheral blood of warm-blooded animals - natural reservoirs is most often limited in time and lasts several days.
Meanwhile, the causative agents of diseases such as tick-borne encephalitis, tick-borne relapsing fever, etc., multiply intensively in the intestines of tick carriers, perform transcoelomic migration and are carried with the hemolymph to various organs, including the ovaries and salivary glands. As a result, the infected female lays infected eggs, i.e. transovarial transmission pathogen to the offspring of the carrier, while the pathogens are not lost during further metamorphosis of the tick from the larva to the nymph and further to the adult, i.e. transphase transmission pathogen.
In addition, ticks retain pathogens in their bodies for a long time. E. N. Pavlovsky (1951) traced the duration of spirochete carriage in ornithodorine ticks to 14 years or more.
Thus, in natural foci, ticks serve as the main link in the epidemic chain, being not only carriers, but also persistent natural guardians (reservoirs) of pathogens.
The doctrine of natural focality examines in detail the methods of transmission of pathogens by carriers, which is important for understanding the possible ways of infecting a person with a particular disease and for its prevention.
Immunoprophylactic methods include immunization of the population. These methods are widely used to prevent infectious diseases. The development of immunoprophylaxis for invasions has a number of significant difficulties and is currently at the development stage. Measures for the prevention of natural focal diseases include measures to control the number of disease carriers (reservoir hosts) and arthropod vectors, by influencing their living conditions and the rate of their reproduction in order to interrupt the circulation of the pathogen within the natural focus.
62. General characteristics of protozoa (Protozoa) Review of the structure of protozoa
This type is represented by unicellular organisms, the body of which consists of cytoplasm and one or more nuclei. A protozoan cell is an independent individual that exhibits all the basic properties of living matter. It performs the functions of the entire organism, whereas the cells of multicellular organisms constitute only part of the organism; each cell depends on many others.
It is generally accepted that single-celled creatures are more primitive than multicellular ones. However, since the entire body of unicellular organisms, by definition, consists of one cell, this cell must be able to do everything: eat, move, attack, escape from enemies, survive unfavorable environmental conditions, reproduce, get rid of metabolic products, and protect from drying out and from excessive penetration of water into the cell.
A multicellular organism can also do all this, but each of its cells, taken individually, is good at doing only one thing. In this sense, the cell of a protozoan is by no means more primitive than the cell of a multicellular organism. Most representatives of the class have microscopic dimensions - 3-150 microns. Only the largest representatives of the species (shell rhizomes) reach 2-3 cm in diameter.
Digestive organelles are digestive vacuoles with digestive enzymes (similar in origin to lysosomes). Nutrition occurs by pino- or phagocytosis. Undigested residues are thrown out. Some protozoa have chloroplasts and feed themselves through photosynthesis.
Freshwater protozoa have osmoregulation organs - contractile vacuoles, which periodically release excess fluid and dissimilation products into the external environment.
Most protozoa have one nucleus, but there are representatives with several nuclei. The nuclei of some protozoa are characterized by polyploidy.
The cytoplasm is heterogeneous. It is divided into a lighter and more homogeneous outer layer, or ectoplasm, and a granular inner layer, or endoplasm. The outer integument is represented by either a cytoplasmic membrane (in amoeba) or a pellicle (in euglena). Foraminifera and sunfish, inhabitants of the sea, have a mineral, or organic, shell.
Irritability is represented by taxis (motor reactions). There are phototaxis, chemotaxis, etc.
Reproduction of protozoa Asexual - by mitosis of the nucleus and division of the cell in two (in amoeba, euglena, ciliates), as well as by schizogony - multiple division (in sporozoans).
Sexual - copulation. The protozoan cell becomes a functional gamete; As a result of the fusion of gametes, a zygote is formed.
Ciliates are characterized by a sexual process - conjugation. It lies in the fact that cells exchange genetic information, but the number of individuals does not increase. Many protozoa are able to exist in two forms - a trophozoite (a vegetative form capable of active feeding and movement) and a cyst, which is formed under unfavorable conditions. The cell is immobilized, dehydrated, covered with a dense membrane, and metabolism slows down sharply. In this form, protozoa are easily transported over long distances by animals, by wind, and dispersed. When exposed to favorable environmental conditions, excystation occurs and the cell begins to function in the trophozoite state. Thus, encystment is not a method of reproduction, but helps the cell survive unfavorable environmental conditions.
Many representatives of the Protozoa phylum are characterized by a life cycle consisting of a regular alternation of life forms. As a rule, there is a change of generations with asexual and sexual reproduction. Cyst formation is not part of the normal life cycle.
The generation time for protozoa is 6-24 hours. This means that, once in the host’s body, the cells begin to multiply exponentially and theoretically can lead to the host’s death. However, this does not happen, since the host’s defense mechanisms come into force.
Representatives of protozoa belonging to the classes Sarcodaceae, Flagellates, Ciliates and Sporozoans are of medical importance.
Typhus is one of the infectious diseases that is caused by rickettsia. Symptoms include the following:
- petichial rash;
- increase in liver size;
- fever;
- enlarged spleen;
- some signs of encephalitis.
The disease is transmitted by lice, most often body lice, not head lice. They excrete rickettsiae in feces for 5 days; in total, the life of lice lasts approximately 17 days.
The development of typhus has several stages:
- rickettsiae enter endothelial cells;
- with the development of rickettsia, destroyed cells begin to appear;
- vascular functions are disrupted and, as a result, improper microcirculation;
- thrombovasculitis of small vessels.
An exacerbation of the disease is observed in the winter-spring period, the incubation period lasts from 5 to 25 days. The first symptom is an increase in temperature, within a few days it can rise to 40 ° C, hallucinations, nausea, headache, insomnia, Rosenberg-Vinokurov symptom may also appear, decreased urination and much more may occur.
Typhus has many symptoms, and if you have one of them, you should go to the hospital to avoid further complications.
Relapsing fever is a disease caused by spirotechae, which are transmitted by ticks. This typhus manifests itself in the form of endemic, sporidic and epidemic diseases. Infection occurs after a bite, the most acute period of development of the disease, the warm season, when ticks are active. The carriers of epidemic typhus are lice.
The incubation period of the disease lasts 1-2 weeks, the infection process is divided into periods. The first symptoms are fever and chills, the formation of a dark red papule at the site of the bite. For the first 2-3 days, the patient continues to have a febrile attack, which is subsequently replaced by other symptoms, such as:
- pain in the calf muscles;
- the skin takes on a yellowish tint;
- slight weakness, malaise;
- The size of the spleen increases slightly.
By the end of the attack, the body temperature returns to normal, which is accompanied by severe sweating. Subsequently, relapsing fever may have 1-2 more attacks of fever, and tick-borne fever may have 3-4. Diagnosis of relapsing typhus is carried out only during attacks, since it is during this period that the pathogen is easy to detect.
Malaria is transmitted by the bite of a mosquito (malarial), the characteristic symptoms of the disease are chills, fever, anemia, an increase in the size of the liver and spleen. The causative agents of malaria live mainly in the cells of the liver and spleen; with a long course of the disease, it also appears in connective tissues.
Malaria has several forms of manifestation: oval malaria, three-day, tropical and four-day. Each form has its own distinctive features, but all are characterized by fever, anemia and splenohepatomegaly.
Plague is a quarantine disease; not only people, but also animals can become infected. The plague microbe is an ovoid bacillus that easily multiplies in nutrient media, but is not resistant to disinfection and dies at a temperature of 100 ° C. Plague is transmitted by the bite of a rodent or by direct contact with an infected person.
The plague has very extensive symptoms; initially, the infected person experiences severe headache, chills, agitation, flushed skin, fever; damage to the membranes of the brain can be a common manifestation.
The most dangerous form of plague is pneumonic; the first manifestation is severe pain in the chest, and pink sputum may be discharged. Without treatment, death is 100% inevitable.
Tularemia is an infectious disease that affects the lymph nodes. The causative agent is non-motile gram-negative aerobic encapsulated bacteria (African, Central Asian, European-Asian). Human infection occurs through contact with an infected rodent. The causative agents of tularemia are not resistant to direct sunlight, disinfection and high temperature. Raw water, especially from reservoirs, can be contaminated.
Symptoms of the disease: high fever, chills, dizziness, muscle pain. There are five forms of development of the disease:
- bubonic;
- ulcerative bubonic;
- anginal-bubonic;
- pulmonary;
- generalized.
Each form has its own additional symptoms, which during the course of the disease have a certain period of manifestation.
Tick-borne encephalitis is transmitted by a tick bite (encephalitis); the pathogens are found in the saliva. There are three types of infection: Central European, Far Eastern, and two-wave meningoencephalitis.
The outcome of the disease is very varied, the patient can recover completely, or become disabled, and in the most severe cases, death is possible.
The disease begins with severe headache, photophobia, muscle pain, fever, in the first days the skin becomes dry, the upper part of the body becomes hyperemic.
Prevention and treatment
To avoid infection with vector-borne diseases, it is necessary to adhere to the following preventive measures:
- during periods of strong activity of various insects, you should avoid long walks in parks and forest belts;
- avoid traveling to countries in the equatorial belt;
- pregnant women should lead a healthy lifestyle and strictly follow the instructions of the attending gynecologist.
Each disease has its own method of treatment, although it is worth noting that some diseases require hospitalization. Typhus is treated with chloramphenicol and tetracycline drugs. Particular attention is paid to the patient's skin, he is wiped daily and, in case of bedsores, a rubber circle is laid. The patient can be fed only liquid food.
Treatment of all forms of relapsing fever is carried out after hospitalization. The patient is prescribed antibiotics from a number of tetracyclines. For prevention, personal protection and disinsection are recommended.
Treatment of malaria is carried out with the help of Quinine, and prevention with the help of the drug Lariam.
Plague treatment is carried out under conditions of strict isolation of the patient in special institutions; the infected person is immediately hospitalized and treatment begins. The main medicine prescribed is tetracycline antibiotics, as a supplement, cardiovascular antibiotics, ascorbic acid in large quantities, various antihistamines and oxygen therapy.
Among the many different infections, there are those that are classified as vector-borne diseases. They cause a number of dangerous pathologies that can be fatal. When such an infection is diagnosed, it is necessary to immediately take appropriate measures to eliminate the disease. Therapy should only be performed by a doctor.
What is a vector-borne route of transmission of infections?
The transmissible route of transmission is the penetration of infected blood into the human blood through a pathogen. This method of transmission of infections occurs in several ways:- Inoculation. If infected blood, through an infectious agent, enters the circulatory system of a healthy person, then this route of transmission is called transmissible. If, for example, an infected insect bites a healthy person, then he becomes infected, and the insect can infect people until it dies.
- Contamination. If there are minor skin lesions on the body of a healthy person, for example scratches, then when feces of an infected animal come into contact with it, infection occurs.
- Specific contamination. The same thing happens as with contamination: infection occurs if you rub a dead infected insect that has already bitten. But in this case, infection occurs once, since the source dies.
Infectious agents
Vector-borne infections also occur due to the following pathogens:- sucking arthropod insects, and these include mosquitoes, ticks (more about tick-borne infections -), mosquitoes, lice, fleas;
- rodents: rats and mice, and gastropods;
If infected bloodsuckers bite a healthy person, then there is a possibility of infection through the blood with such serious diseases.
- food products with insufficient heat treatment, and these can be cereals, vegetables, fruits, if they have been contaminated with the urine and feces of sick animals.
Infectious diseases that are transmitted vector-borne
Symptoms of the disease are:
- high temperature;
- skin rash;
- enlarged spleen and liver;
- vomiting, headaches and sleep disturbances.
This disease has a long incubation period - a period of 5 to 25 days. At the first symptoms, you should immediately consult a doctor to avoid complications.
Relapsing fever
Occurs after a tick bite. They can be infected with spirochetes, which, during a bite, enter the blood of a healthy person. The most dangerous period occurs in warm spring.Malaria
Occurs after a malaria mosquito bite. This disease has the following symptoms:- low hemoglobin;
- high temperature;
- enlarged liver and spleen.
Epidemic typhus
Occurs when bitten by lice. The incubation period of the disease can last up to 14 days. First, the temperature rises, the bite site turns red, forming a papule. Subsequently, other symptoms appear:- pain in the leg muscles;
- weakness;
- slight enlargement of the spleen;
- yellowing of the skin.
Plague
It is transmitted through rodents, which are carriers of the ovoid bacillus, and also through their bite. When placed in a nutrient medium, the rods begin to develop very quickly. They die when heated to 100 degrees, as well as when treated with disinfectants.Symptoms of the plague are:
- headache;
- redness of the skin;
- high temperature.
Tularemia
Occurs from a bite or contact with an infected rodent. The causative agent of the disease is bacteria in capsules. They die in the sun, at high temperatures and when surfaces are treated with disinfectants. You can become infected by drinking unboiled water from a natural reservoir if it turns out to be contaminated.The disease is diagnosed if there is:
- high temperature;
- muscle pain;
- severe dizziness.
Encephalitis
Occurs when bitten by ticks infected with encephalitis. The causative agent of the disease is in the saliva of the tick. Symptoms of encephalitis:- headache;
- elevated temperature;
- redness and dryness of the skin.
Prevention
The main preventive measures include avoiding contact with blood-sucking insects. To do this, a number of measures should be taken:
- in the evening, wear clothes with long sleeves and thick fabric, with zippers and Velcro fasteners;
- do not walk in the forest, park, or near bodies of standing water in the evening;
- install mosquito nets and curtains over beds in houses;
- carry out chemical treatment of areas where insects accumulate;
- take medications to prevent diseases and carry out timely vaccinations;
- It is advisable to drink only boiled water.
Blood-borne infections
Infections that are classified as blood-borne are transmitted through donor blood during transfusion. HIV infections, as well as hepatitis B and C, can be transmitted through blood. Nowadays, there are a large number of people infected with these types of hepatitis.Due to the spread of these infections, there is an increasing need to strengthen preventive measures when transfusing blood to patients. Such measures include:
- measures to ensure safety during the collection of material, procurement and storage of donor blood, organs and tissues, as well as increased safety and sterility measures when using donor materials;
- documents and examination results of blood, organ, sperm and tissue donors must be carefully examined;
- Donors must be re-examined six months after donation.
