The main characteristic of natural focaldiseases is that their pathogens are transmitted to humans from birds or animals. As a rule, transmission occurs through the bites of blood-sucking insects, for example, mosquitoes. Several pathogens can co-exist in one natural focus: bacteria, viruses, helminths, protozoa, etc. In order to protect themselves against natural focal diseases, many of which pose a serious threat to people's lives, it is important to have information about the transmission routes and methods of prevention diseases.
The phrase "natural hearth" directlyindicates that the source of infection exists in nature. Transmissible and natural focal diseases are associated with certain biogeocenoses. The causative agents of natural focal diseases tend to be transmitted from people to animals, which means that a person who finds himself in a similar biogeocenosis may be exposed to infection. In this case, the pathogens are transmitted in various ways: through insect bites, inhalation of dried excrement of infected animals, etc.
The study of natural focal diseases Academician Pavlovsky is one of the most outstanding achievements of biological science.
Teaching Pavlovsky states that inSome landscapes have foci of diseases that can be transmitted to humans. These centers were formed during the long evolutionary development of biogeocenosis.
The disease natural focal occurs when three links simultaneously occur:
For example, to natural focal diseasesPendinsky ulcer, common in some areas of Central Asia. The causative agent of the disease are Leishmania. The reservoir of leishmania are gerbils - small rodents living in deserts. And leishmania is transmitted through mosquito bites.
Foci of several diseases may be simultaneously present on one territory, which is important to consider when developing preventive measures.
The disease is natural focal can be of two types:
E. N.Pavlovsky singled out another type of natural foci - anthropourgic. The appearance of these foci is due to human activity and the ability of some vectors to move to a synanthropic existence. Such carriers, such as mosquitoes or ticks, are found mainly in urban or rural conditions, that is, not far from a person’s home.
Natural focal infectious diseases candistributed by two types of carriers: specific and non-specific. In specific carrier organisms, the causative agent of the disease goes through some of the stages of its life cycle: it multiplies, accumulates, or even from an egg turns into a larva. The pathogen can support its vital activity only in the body of a particular carrier, adapting to it in the process of evolutionary development.
Nonspecific carriers move pathogens mechanically. In this case, the pathogen for some time resides either on the trunk or in the intestine of the distributor.
Infection with natural focal diseases can occur in various ways:
Tick-borne encephalitis - a diseasenatural focal, characterized by severe intoxication and damage to the brain and spinal cord. Patients develop persistent irreversible neurological disorders, death is possible.
Japanese encephalitis is an acute disease,flowing with damage to the brain and its membranes. A vector of Japanese encephalitis are mosquitoes. The main symptoms are lethargy, fatigue, speech and vision disorders, fever, chills and vomiting. Death occurs in 40-70% of cases.
Rabies is one of the most dangerous.natural focal diseases. The signs are anxiety, hypersensitivity to bright light, insomnia, convulsions, hydrophobia. The patient sees hallucinations, becomes aggressive.
Foot and mouth disease - a natural focal disease that affectsmucous membranes, periungual bed and folds between the fingers. The pathogen enters the body through food. The onset of FMD is quite acute, occurring with a sharp increase in temperature. The prognosis is often favorable, although serious complications may occur in children.
Anthrax is a disease that has two forms:cutaneous and septic. The cutaneous form is characterized by the fact that numerous ulcers appear. This form develops rather slowly and is well treatable. The septic form is more dangerous, death can occur in just a few days.
Учение Павловского о природно-очаговых diseases has had a profound effect on the approach to prevention. If initially the main measure of prevention of epidemics was the treatment of infected people and the destruction of vectors, such as mosquitoes or ticks, then today the main goal is the elimination of animal reservoirs.
In order to protect yourself from natural focaldiseases, it is important to observe a number of preventive measures: to make timely vaccinations, not to visit the habitats of animals that are carriers of pathogens, and also to protect themselves from the bites of insect vectors with the help of closed clothing or using special repellents.
