Components of natural focus are: 1) pathogen; 2) animals susceptible to the causative agent - reservoirs: 3) a corresponding complex of natural-climatic conditions, in which there exists this biogeocenosis. Special group natural focal diseases make up transmissive diseases Such as leishmaniasis, tripanosomosis, tick-borne encephalitis, etc. Therefore, the obligatory component of the natural focus of the transmissive disease is also carrier.

The category of diseases with natural foci was allocated Acad. E.N. Pavlovsky in 1939 on the basis of expeditionary, laboratory and experimental work. Currently, natural focal diseases are actively learning in most countries of the world. The development of new, unnecessary or low-noise territories leads to the discovery and new, unknown previously natural focal diseases.

Some natural focal diseases are characterized. endemism, those. Massage on strictly limited territories. This is due to the fact that the pathogens of the respective diseases, their intermediate hosts, animal tanks or carriers are found only in certain biogeocenosis. So, only four types of pulmonary salts from p were resets in separate areas of Japan. Paragonimus.. Their resettlement prevents the narrow specificity for intermediate hosts, which live only in some reservoirs of Japan, and the natural tank are such endemic species of animals as a Japanese meadow mouse or a Japanese cunnic.

Viruses of some shapes hemorrhagic fever It is found only in certain zones of East Africa, because there is an area of \u200b\u200btheir specific carryers - ticks from p. Atyouotta..

A small amount of natural focal diseases occurs almost everywhere. These are such diseases whose pathogens are usually not related to the cycle of their development with an external environment and amaze a wide variety of owners. Diseases of this kind include, for example, toxoplasmosis and trichinosis. These natural focal diseases may become infected in any natural climatic zone in any environmental system.

The absolute majority of natural focal diseases affects a person only in case of hitting it to the appropriate focus (on hunting, fishing, in tourist campaigns, in geological parties, etc.) under the conditions of its susceptibility to them. So, taiga Encephalitis man infects with a bite infected tick, and opistorhoz - Singing insufficiently thermally treated fish with feline sticks.

Prevention of natural focal diseases Represents special difficulties. Due to the fact that a large number of hosts are included in the circulation of the causative agent, and often carriers, the destruction of whole biogenotic complexes arising from the evolutionary process, are environmentally unreasonable, harmful and even technically impossible. Only in those cases, if the foci are small and well-studied, it is possible to complex transformation of such biogeocenoses in the direction that excludes the circulation of the pathogen. Thus, the recultivation of deserted landscapes with the creation of irrigated horticultural farms in their place, carried out on the background of combating deserted rodents and mosquitoes, can sharply reduce the incidence of leishmaniosa. In most cases of natural focal diseases, their prevention should be aimed primarily on individual protection (preventing bite with blood-sized arthropods, thermal processing of food products, etc.) in accordance with the circulation paths in the nature of specific pathogens.

Components of natural focus are: 1) pathogen; 2) animals susceptible to the causative agent - reservoirs: 3) a corresponding complex of natural-climatic conditions, in which there exists this biogeocenosis. A special group of natural focal diseases make up transmissive diseases Such as leishmaniasis, tripanosomosis, tick-borne encephalitis, etc. Therefore, the obligatory component of the natural focus of the transmissive disease is also carrier. The structure of such a hearth is shown in Fig. 18.8.

1 - causative agent - Leinsmania, 2 - Natural tank - Mongolian gerbils, 3 - pathogen carrier - Mosquito, 4 - Rodent holes in the semi-derangements of Central Asia, 5 - The causative agent of the disease is a wide tape 6 - Natural reservoir - fishing mammals, 7 - Intermediate hosts - cyclops and fish, 8 - large freshwater reservoirs of Northern Eurasia

The category of diseases with natural foci was allocated Acad. E.N. Pavlovsky in 1939 on the basis of expeditionary, laboratory and experimental work. Currently, natural focal diseases are actively learning in most countries of the world. The development of new, unnecessary or low-noise territories leads to the discovery and new, unknown previously natural focal diseases.

Fig . 18.9. Mite Amblyomma sp.

Some natural focal diseases are characterized. endemism, those. Massage on strictly limited territories. This is due to the fact that the pathogens of the respective diseases, their intermediate hosts, animal tanks or carriers are found only in certain biogeocenosis. So, only four types of pulmonary salts from p were resets in separate areas of Japan. Paragonimus. (See Section 20.1.1.3). Their resettlement prevents the narrow specificity for intermediate hosts, which live only in some reservoirs of Japan, and the natural tank are such endemic species of animals as a Japanese meadow mouse or a Japanese cunnic.

Viruses of some shapes hemorrhagic fever It is found only in certain zones of East Africa, because there is an area of \u200b\u200btheir specific carryers - ticks from p. Atyouotta. (Fig. 18.9).

A small amount of natural focal diseases occurs almost everywhere. These are such diseases whose pathogens are usually not related to the cycle of their development with an external environment and amaze a wide variety of owners. Diseases of this kind include, for example, toxoplasmosis and trichinosis. These natural focal diseases may become infected in any natural climatic zone in any environmental system.

The absolute majority of natural focal diseases affects a person only in case of hitting it to the appropriate focus (on hunting, fishing, in tourist campaigns, in geological parties, etc.) under the conditions of its susceptibility to them. So, taiga Encephalitis man infects with a bite infected tick, and opistorhoz - Singing insufficiently thermally treated fish with feline sticks.

Prevention of natural focal diseases Represents special difficulties. Due to the fact that a large number of hosts are included in the circulation of the causative agent, and often carriers, the destruction of whole biogenotic complexes arising from the evolutionary process, are environmentally unreasonable, harmful and even technically impossible. Only in those cases, if the foci are small and well-studied, it is possible to complex transformation of such biogeocenoses in the direction that excludes the circulation of the pathogen. Thus, the recultivation of deserted landscapes with the creation of irrigated horticultural farms in their place, carried out on the background of combating deserted rodents and mosquitoes, can sharply reduce the incidence of leishmaniosa. In most cases of natural focal diseases, their prevention should be aimed primarily on individual protection (preventing bite with blood-sized arthropods, thermal processing of food products, etc.) in accordance with the circulation paths in the nature of specific pathogens.

Natural focal infections are diseases common for humans and animals, whose pathogens can be transmitted from animals to a person, are characterized by the ability of pathogens for a long time to persist in the external environment in individual territories - natural foci, in animal organisms, including rodents, birds, Blood-axes, which are sources and carriers of these infections.

The most common in the territory of the Republic of Belarus such natural focal infections as tularemia, hemorrhagic fever with renal syndrome, leptospirosis, yersiniosis, pseudotuberculosis, lemaryiosis.

Of particular importance, these infections acquire in the active spring-autumn period and especially for citizens traveling to the natural environment, country sitesAs well as for children of summer country health facilities.

Infection of natural focal infections occurs in different ways:

Production infections are associated with work in the forest or near it (construction, forest harvesting, etc.). Infection of people is also also in industrial enterprises, to the territory or in the workshop whose forest rodents penetrate. Agricultural infections occur mainly in autumn and in winter during the transportation of hay and straw, folded into stacks and omeets in the forest or near him. With the onset of cold weather in a lot of quantities, field and forest rodents are aligned. In the autumn period, people occupied on the cleaning and processing of flax are possible. The disease can be registered among shepherds, beekeepers, workers of livestock farms, warehouses and granaries, as well as in persons engaged in disassembling potato and beetrootes. Possible infection of workers and employees traveling to the collective cleaning of vegetables.

Infection when working in gardens, at the gardens and dachas. Favorite places of rodent dislocation in dacha arrays are country houses, sheds, garbage piles, dumps of conceded trees and shrubs. In the spring, in the country houses and in the adjacent territory, there are traces of rodents (litter and dry allocations of rodents), which can inhalation in the subsequent cause diseases with natural focal infections.

Infection at the place of residence (domestic) occur mainly from October to February in homes located near the forest. They are due to the fact that forest rodents populate the cellar, sheds, hayrs, heaps of twigs and woodwoods, located on the territory of the estates, and sometimes penetrate the living quarters.

Infection with short-term stay on vacation in the forest (walks, tourist hiking, fishing, hunting, etc.) occur mainly in the summer and early autumn. Possible infection during overnight stays in tents, forest shops, temporary houses, etc., available for rodents, as well as with an unsanitary state of health facilities. These infesses are most characteristic of the urban population.

Infection can also occur in the bite of bloodsowing insects: ticks, fleas, blind, etc. (most often happens in natural foci of Tularemia). A person can get infected through water of water bodies (swamps, ponds, shallow rivers, canals) when bathing, fishing, various economic activities.

Hemorrhagic fever with renal syndrome (GLPS)

Hemorrhagic fever with renal syndrome (GLPS) - acute viral natural focal infectioncharacterized by defeat vascular system and the development of acute renal failurewhich can lead to a fatal outcome.

The GLPS virus penetrates the human body through airways, gastrointestinal and damaged skin.

The source of the virus is miserable rodents that distinguish the virus with urine and feces that can infect environmental objects, food and household items.

Transmission paths: Aerogenic (air-dust) when inhaling dust, infected with rodents and alimentary (infected food).

Leptospirosis

Leptospirosis - acute infectious bacterial disease, main clinical manifestations which are symptoms of damage to the vascular system, liver and kidney, with the development of acute hepatic or renal failure.

Pathways: bacteria of various species that are inherent in certain types of animals - pigs, dogs, rats, etc. Leptospira penetrate the human body through damaged skin, intact mucous membranes and gastrointestinal tract.

Sources of infection: in natural conditions - many types of rodents, as well as pets (pigs, large cattle, dogs, etc.). The animals of patients and carriers are isolated to the external leptospira with urine and infect reservoirs, food and home item (rodents).

Transfer paths - contact when communicating with patients with animals and infected objects of the external environment, water, food.

Liseriosis

Liseriosis is an acute infectious natural-focal bacterial disease, which is characterized by various clinical manifestations: angina, conjunctivitis, lymphadenitis, meningoencephalitis, gastroenteritis, septic state.

The causative agent is a bacterium of lisureness, intracellular microorganism. It has the ability to preserve and multiply in soil, water, food products (meat, milk, vegetables) even in the conditions of cold.

Sources of infection: Animals (agricultural, homemade, wild), as well as birds (decorative and home).

Path transmission infection:

food, with the use of infected products;

aerogenic, with inhalation of dust infected with rodents;

contact, when communicating with patients with animals and infected objects of the external environment;

transplascent, from the Mother of Fruit or Newborn (the development of septic conditions, the death of fruits and children in the first days of life). Special danger for pregnant women is the use of raw meat, removal of samples from raw minced meat.

Tularemia

Tulyarania is a sharp infectious disease that is transmitted to man from rodents (water rat, ondatra, hare, horselock, grounding, rat, mouse).

The causative agent of Tularerey is a bacterium with considerable resistance in the external environment.

The source of infection under Tularemia for humans are sick rodents, as well as the objects of the external environment infected with the discharges of sick animals.

A distinctive feature of Tularemia is the set of ways to transfer:

a person's infection can occur when contact with mile-like rodents;

the infection can be easily applied with "dirty" hands on the mucous membrane of the eye, mouth, for food products;

you can also get infected when inhalation of dust, which is formed during the operation of the threshing, carrying hay, etc.;

during the catch of water rat, the removal of the skins, the processing of the furs (the presence of skin damage: abrasions, scratches of cuts - increases the risk of infection);

when eating contaminated with excrement or corpses of the fallen rodents of food and water;

with the bite of bloodsowing insects: ticks, fleas, blind, etc. (most often occurs in the natural foci of Tularemia).

The clinical picture is characterized by the emergence of one-sided lymphadenitis (increase lymph nodes), conjunctivitis, angin. The form of the disease depends on the place of penetration of the pathogen of Tularemia into the human body.

Iraciniosal infection

There are intestinal rationsiniosis and pseudotuberculosis.

Iraciniosis is an acute human and animal infectious disease. The pathogens of the yersiniosis infection are widespread in nature, multiply in the soil, on vegetables, fruits, berries, meat, dairy and other products.

Pseudotuberculosis - acute infectious bacterial disease with polymorphic clinical picture From the scarlatin-like fever, lesions of the joints to food toxicoinfection and septic conditions.

Sources of infection with heersiniosis and pseudotuberculosis - different kinds rodents.

The pathogen: bacteria that are kept continuing and multiply in an external environment and food products (vegetables, fruits, milk, etc.), even in cold conditions.

Transfer paths - food (through infected products) and contact.

The most significant transmission factors of infection are food products used without heat treatment, which often leads to outbreaks in organized children's teams, in violation of the storage rules of vegetables, preparation and storage of raw vegetables dishes.

Should stay on more detailed description synantropic types of rodents, such as house mouse, black and gray rat. These disease carriers are dangerous because they live in close proximity to man, this in turn increases the likelihood of infection. The human activity is for mathithic rodents source of housing, shelter and feed base.

House mouse. The bulk of animals constantly lives in the buildings of man, which is especially characteristic of urban populations .. In nature, it is mostly in the twilight clock, in the construction of the time of daily activity in the opposite dependence on human activity. With favorable temperature and feed conditions, it is breed all year round, although some winter depression is observed. The average bulge from 5 to 7 cubs. Almost omnivorous appearance, the seeds of cereals, legumes and comprehensive seeds eat, the remains of insects, green and juicy feed are constantly found in their feed. Brings tremendous harm in settlements as an omnivorous pest of food reserves.

Rat gray. Rat is common throughout Belarus. In the summer, some individuals move into natural biotopes and returns to human housing for the winter. However, there is an opinion on the existence of two populations: synanthropic and "wild." In the presence of food can permanently reside even in industrial refrigerators. In natural conditions, Roet holes. Most of the year multiplies. Up to three litters per year on average 7 cubs. Young individuals aged 3 - 4 months can multiply. Omnivorous. In settlements, feeds mainly by garbage. Rat black. Completed throughout the territory of the republic. Being a warm-consuming than gray rat, inhabit natural biotopes only in areas with a softer climate. The rest of the range is associated with the housing of a person. In places of living with a gray rat, adheres to the upper floors, up to attic rooms. Gnobs builds on Earth under floor flooring or in the inter-storey structures of buildings. Per year brings 2 - 3 litters for 6 cubs in each. The food includes all permissible vegetable and animal feed.

To avoid infection with natural focal infections, it is necessary to observe simple rules:

it is regularly cleaning the territory of the area from the garbage, prevent the formation of garbage coup, trees, dry and other waste, which are places of mass accumulation and reproduction of rodents. Trash to export on the TWW polygons, prevent the formation of landfills in the forests;

ensure the rodent resistance of residential premises, to regularly destroy rodents of poisoners. Poisonman can be purchased at the territorial center of hygiene and epidemiology;

in no case can not catch and take rodents in the hands. If in the house or on the plot, in the environment you found the corpses of rodents or other animals, do not touch them with your hands and in no case allow it to make it children;

cleaning the house, basements after the winter, where there are traces of rodent vital activity, carry out only a wet method, without preliminary sweeping of garbage and mouse, using the means of personal protection of the respiratory organs, hands. Use for cleaning chlorine-containing drug. Solutions for cleaning prepare according to the attached instructions for the drug. Dishes It is advisable to quote boiling water, or to process any disinfectantAccording to the instructions for use;

bedding (mattresses, pillows, etc.) dry in the sun for several hours, periodically turning over. Bed linen and other accessories before use must be washed;

food products should be stored in an inaccessible place for rodents and other animals, in hermetic container. If nevertheless, you found traces of rodents about either on food products - then such products are better not to eat in food, comply with the technology of preparation and timing of the sale of salads from raw vegetables;

during work or rest in nature, you should not wash your hands before using food in the reservoir, and in no case drink water from the reservoir. To wash your hands, it is better to take water with you, or to gain in the nearest settlement in the well, column, water supply. For thickening, thirst is recommended to take with me bottled water;

in order to avoid infection during agricultural development, during hay and harvest (grilling dry hay, straw, loading, transportation, discharging, etc.) it is necessary to use a four-layer marlay bandage and mittens;

when choosing a place for overnight stays or day leisure, stamped areas of the forest with thick shrubs and grass, old stumps, dressed trees, should be avoided. It is better to choose the edge of the forest or the melan. It is necessary to lay a light blanket for Earth, a raincoat, so as not to have direct contact with the soil infected with rodents, grass;

under the night in the tent, it is necessary to cover all the slots through which rodents can penetrate. You can not sleep in the haystacks, straw, located in the forest, as they are often infected with the discharge of rodents, do not use the old straw, hay and leaves as a litter;

going into the forest in the spring - in the fall, it is necessary to use repellents - means of scaring insects; Choose clothes that prevented insect penetration to the body;

be sure to wear a headdress (especially for women and children), to conduct an inspection itself or a mutual inspection for improving ticks;

it should also be paid to the storage of food products, especially in the cellar, basements, garages. Fruits and greens should be stored in boxes. It is necessary to periodically remove fallen vegetables, and also to remove the garbage, not to eat vegetables and fruits, with traces of damage from rodents.

Department of particularly dangerous infections.

Most transmissible diseases are associated with certain areas where wild animals are common - carriers of these diseases. The carriers and carriers of transmissive diseases live among animals inhabiting this territory and are in complex relationships between themselves and with environmental conditions. They are well adapted to the habitat. Natural foci of transmissive diseases arose in the process of evolution and exist independently of humans. Finding into the territory of the natural focus, a person can become infected with transmissible disease in the uncens of carriers.

Transmissive diseases with natural foci are characterized by the following features:

Circulate in nature independently of the person;

The reservoir are wild animals that make up with causative agents and carriers of a bioceneotic complex;

Completed in the territory with a specific landscape, climate and biocenosis. Components of natural hearth:

Causative agent;

Reservoir owner;

Complex of natural conditions;

The presence of a carrier if transmissive.
An example of a transmissive disease with natural foci can be a tick return tit. Foci is found in deserts and semi-deserts. The reservoir hosts are dickeranes, gerbils, etc. Carriers - village ticks living in nonorah, caves, abandoned housing. Feeding the blood of tank animals, ticks support the focus for many years.

A transvocate transfer of the pathogen is possible, i.e. Transmission through egg cells from one generation to another. From the infected eggs, larvae, nymphs and imago, contaminated by spirochetes, causing tick-free returning, are developing from an infected egg. This method of transmitting the pathogen allows you to maintain it for a long time. Ticks are not only carriers, but also the reservoir masculient owners.

Transmissive diseases with natural foci include plague, leishmaniasis, tick-free spring - summer encephalitis, etc.

Some helminthiasis (dihlobotryosis, opisthorchosis, trichinosis and others can be attributed to natural focal diseases.

The doctrine of the natural foci made it possible to develop measures of prevention and protection against these diseases. Prevention involves individual protection and destruction of tank animals.

Anthroponose -diseases, whose pathogens affect only a person. The biological owner and the source of pathogens at the same time is an infected person (dysenteric amoeba, giardia, trichomonada, etc.).

Zoonoses -diseases, whose pathogens affect the human and animal organism. The source of causative agents of diseases is home and wild animals (Leishmania, Balantium, etc.).

· Protozoology

· helmintology

· arachnentomology.

The body of the simplest consists of a shell, cytoplasm, kernels, various organelles, providing nutrition, movement, highlighting. The simplest moves with the help of pseudopodia (sarcodic), flagella and abnorming membranes (flagella), cilia (wilderness infusories).

Single-cell food serve organic particles, including living microorganisms, as well as dissolved nutrients in the environment. Some swallow food particles by cell mouth, others absorb dietary particles using pseudo-pending (falselyones) formed in any body portion. In this case, the particle seems to be strengthened and turns out inside the vacuole in the cytoplasm of the simplest, where and digested (pinocytosis). In some types of simplest food occurs by suction of nutritional juices and dissolved nutrients with the surface of the body (endoosmotically).

The simplest of some species are capable of incinerate, i.e. they are rounded and covered with a dense shell (for example, a dysenteric amoeba). Cysts are more resistant to the effects of adverse external factors than vegetative forms. If you get to favorable conditions, the simplest out of cysts and begin to multiply.

The simplest people living in the human body belong to the kingdom Animalia., facing Protozoa.. In the face of the simplest ( Protozoa) Three types are isolated: Saromastigophora.,Apicomplexa. and Ciliophora,available meaningful ( see Table).

Components of natural focus are: 1) pathogen; 2) animals susceptible to the causative agent - reservoirs: 3) a corresponding complex of natural-climatic conditions, in which there exists this biogeocenosis. A special group of natural focal diseases make up transmissive diseases Such as leishmaniasis, tripanosomosis, tick-borne encephalitis, etc. Therefore, the obligatory component of the natural focus of the transmissive disease is also carrier. The structure of such a hearth is shown in Fig. 18.8.

1 - causative agent - Leinsmania, 2 - Natural tank - Mongolian gerbils, 3 - pathogen carrier - Mosquito, 4 - Rodent holes in the semi-derangements of Central Asia, 5 - The causative agent of the disease is a wide tape 6 - Natural reservoir - fishing mammals, 7 - Intermediate hosts - cyclops and fish, 8 - large freshwater reservoirs of Northern Eurasia

The category of diseases with natural foci was allocated Acad. E.N. Pavlovsky in 1939 on the basis of expeditionary, laboratory and experimental work. Currently, natural focal diseases are actively learning in most countries of the world. The development of new, unnecessary or low-noise territories leads to the discovery and new, unknown previously natural focal diseases.

Fig . 18.9. Mite Amblyomma sp.

Some natural focal diseases are characterized. endemism, those. Massage on strictly limited territories. This is due to the fact that the pathogens of the respective diseases, their intermediate hosts, animal tanks or carriers are found only in certain biogeocenosis. So, only four types of pulmonary salts from p were resets in separate areas of Japan. Paragonimus. (See Section 20.1.1.3). Their resettlement prevents the narrow specificity for intermediate hosts, which live only in some reservoirs of Japan, and the natural tank are such endemic species of animals as a Japanese meadow mouse or a Japanese cunnic.

Viruses of some shapes hemorrhagic fever It is found only in certain zones of East Africa, because there is an area of \u200b\u200btheir specific carryers - ticks from p. Atyouotta. (Fig. 18.9).

A small amount of natural focal diseases occurs almost everywhere. These are such diseases whose pathogens are usually not related to the cycle of their development with an external environment and amaze a wide variety of owners. Diseases of this kind include, for example, toxoplasmosis and trichinosis. These natural focal diseases may become infected in any natural climatic zone in any environmental system.

The absolute majority of natural focal diseases affects a person only in case of hitting it to the appropriate focus (on hunting, fishing, in tourist campaigns, in geological parties, etc.) under the conditions of its susceptibility to them. So, taiga Encephalitis man infects with a bite infected tick, and opistorhoz - Singing insufficiently thermally treated fish with feline sticks.

Prevention of natural focal diseases Represents special difficulties. Due to the fact that a large number of hosts are included in the circulation of the causative agent, and often carriers, the destruction of whole biogenotic complexes arising from the evolutionary process, are environmentally unreasonable, harmful and even technically impossible. Only in those cases, if the foci are small and well-studied, it is possible to complex transformation of such biogeocenoses in the direction that excludes the circulation of the pathogen. Thus, the recultivation of deserted landscapes with the creation of irrigated horticultural farms in their place, carried out on the background of combating deserted rodents and mosquitoes, can sharply reduce the incidence of leishmaniosa. In most cases of natural focal diseases, their prevention should be aimed primarily on individual protection (preventing bite with blood-sized arthropods, thermal processing of food products, etc.) in accordance with the circulation paths in the nature of specific pathogens.