From Big Medical Encyclopedia

TROPICAL DISEASES — troupe of the diseases extended among the population in areas with tropical or subtropical climate. T. 6. are subdivided into infectious and noncontagious diseases.

Infectious tropical diseases. It is accepted to carry infectious and parasitic (invasive) diseases to this group, endemic for tropics. They have paramount value in pathology of the person among T., strike millions of inhabitants of tropics and subtropics and cause huge economic damage. Among them are the most widespread:

from among viral diseases — yellow fever (see), flebotomny fever (see), a dengue (see), tropical mosquito viral fevers (see); from among rickettsioses — tsutsugamush (see), the Marseilles fever (see), spotty fever of the Rocky Mountains (see); from bacterial diseases — a bartonellosis (see), a melioidosis (see), a tick-borne typhinia (see the Typhinia), pint (see), a frambeziya (see), a badge (see. From a pirokhetoza); from mycoses — fungus diseases of skin (see), the Madura stopsha (see), chromomycosis (see); from protozoocall — malaria (see), a trypanosomiasis (see), leyshmanioza (see); from helminthoses — ankilostomidoza (see), shistosomatoza (see), a dracunculosis (see), filariases (see); from entomoz — ■ sarkopsillez (see) and mioses (see). With tropical protozooza it is struck apprx. 250 million, and tropical helminthoses — more than 1,5 billion inhabitants of tropical countries.

Prevalence of tropical infections and invasions generally in the countries with roast telimaty is caused by a complex of natural and social factors. From natural factors paramount value has the heat balance of the land surface defining high temperatures of air, water and soil in a zone of tropics and subtropics. In this regard only in tropics among people the most thermophilic causative agents of infectious diseases, napr circulate, such as virus of yellow fever, filarias, shisto-catfishes, temperature optimum of development to-rykh lies within 20 — 30e. Thermophilic activators T. do not take roots in midlatitudes, even in the presence of here carriers and intermediate owners, because of a lack of heat for their development. In this regard in zones of a temperate climate the centers, napr, yellow fever, a vukhererioz do not form (see). Importance for emergence of T. has existence in a zone of tropics of thermophilic arthropod carriers and mollusks — intermediate owners, and at zoonoza (see) also corresponding hematothermal animals — sources of activators. So, e.g., the centers of a tsetse-fly disease (see) cannot arise where on an environment there are no tsetse flies (see the Tsetse fly), being carriers of the causative agent of a sleeping sickness (Trypanosoma gam-biense). The centers of the Japanese schistosomatosis (see Shistosomatoza) do not appear in those areas where there are no mollusks of the sort Oncomela-nia, being intermediate owners of the activator of the Japanese schistosomatosis (Schistosoma japoni-cum). The endemic centers of yellow fever exist only in those territories where the different types of monkeys serving by specific owners of a virus (Flavivirus febricis) live in the nature.

Prevalence of infectious T. it is to some extent caused also by socio-economic factors — type of dwellings, working conditions and life, level a dignity. cultures, system and level of development of health care, etc. Infectious T. meet considerably more often where social and economic conditions and the held anti-epidemic events limit their distribution not enough. More the fact that T are especially characteristic of tropical countries not only actually is explained by it., but also those in the past everywhere widespread diseases, incidence to-rymi in the developed countries managed to be liquidated or to limit considerably, napr, a leprosy (see), trachoma (see).

In the territory of the USSR, hl. obr. in the republics of Transcaucasia and Central Asia, in the past there were extensive centers of nek-ry T. As a result of purposeful actions nek-ry of them are liquidated completely, napr, a dracunculosis, a leushmaniosis of city type, the others (malaria, a visceral leushmaniosis, ankilostomidoza, etc.) remained only in the limited centers.

Because infectious T. take the paramount place in pathology of the population of tropical countries, the Special program of WHO for fight against tropical diseases existing since 1976 and which is actively supported by the Soviet Union was created. Fight against such T is provided in this program., as malaria, leyshmanioza, three panosomoza, shistosomatoza, filariases, etc.

Noncontagious tropical diseases include the diseases connected with influence of hot climate, a disease of food, the defeats arising at contact of the person with the poisonous animals living in tropics and also the nek-ry genetic anomalies inherent to inhabitants of tropics.

Carry to the diseases connected with immediate effect of hot climate: a thermal shock (see), a syndrome of salt insufficiency (see the Water salt metabolism, Mineral metabolism). The frustration connected with overheating arise at children and elderly people more often, and also at the military personnel at insufficient acclimatization in hot climate. Enters into the same group tropical deprive (Miliaria rubra) — the burdensome thermal dermatitis arising in connection with the expressed perspiration.

From diseases of food in tropics meet a kwasiorkor (see), to a spr (see) and beriberi more often (see). To this group T. it is possible to carry also the poisonings observed at consumption of the products containing toxicants. So, e.g., an epidemic edema, or an argemonizm, develops at consumption of the mustard containing impurity of the argemonovy oil received from the Mexican poppy (Argemona mexicana). Clinically the disease is shown by hypostases in combination with symptoms of damage of heart, but without the paralyzes and anesthesia characteristic of beriberi. The disease quite often comes to an end with death. The outbreaks of epidemic dropsy are described in India, Mauritius and Fiji.

The atactic spastic paraplegia, or a lathyrism (see), arises at consumption ranks (a special type of the Lathi-rus lentil) containing hydrocianic to - that. The phenomena of a spastic lower paraplegia (see), disturbance of an urination, sometimes — an incontience a calla, etc. are characteristic of a disease. Disease is chronic, quite often comes to an end with disability. Cases are described in India, Ethiopia, Algeria, Afghanistan.

The emetic disease arises at children at the use of immature fruits of a tree of Blighia sapida, to-rye contain toxicant hypoglycine. The main symptoms of poisoning — vomiting, spasms, a coma.

In a pathogeny of a disease the important role belongs to the expressed hypoglycemia and fatty regeneration of a liver, kidneys, a pancreas and myocardium. The emetic disease is described in Jamaica and in the countries of the Western Africa.

Inhabitants of tropics quite often are surprised poisonous animals (see). Toxins of poisonous glands get into a human body at stings of nek-ry snakes, fishes, spiders or at a prick about appendages of a body of fishes and scorpions. Stings of blood-sicking arthropods can be followed not only acute local reaction (necrosis), but also the general. So-called tick-borne paralyzes are described at people and animals at mass stings of mites of the nek-ry types relating to the sort Ixodes, Hyalomma, Rhipice-phalusn Haemaphisalis. The most often acute ascending paralysis of motive muscles as a result of a long krovososaniye of mites is registered in South America and Australia. Tick-borne paralyzes usually come to an end with recovery, however lethal outcomes owing to paralysis of respiratory muscles are registered. Stings of mites of the sort Ornithodoros coriaceus are so painful that the population of Mexico fears these mites not less, than a rattlesnake.

The St. 350 species of scorpions are widespread in tropics and subtropics, nek-ry of them are more dangerous, than venomous snakes. Poison of scorpions contains strong neurotoxins, defiant pains, spasms, a zatrudnennost of breath, shock and quite often death. In the countries of the Mediterranean, tropical Africa and the Middle East scorpions of three types are extremely dangerous:

Andro-ctonus australis, poison to-rogo can be deadly to the child; Buthus quinquestriatus and V. crassi-cauda, to-rykh perish from poison annually hundreds of children (the lethality among victims reaches 50%). In Mexico the big lethality from poison of a scorpion of Cent-ruroides suffusus is registered. In the countries of South America about 25% of victims perish from poison of scorpions of the sort Tityus. Apply serum against poison of these insects to treatment.

From poisonous spiders representatives of the sort Latrodectus are most widespread in tropics («the black widow», «the gray widow», «the redlegged widow», etc.)> the sting to-rykh is very painful, does not give in to action of analgetics and sedative drugs, is followed by spasms, vomiting, shock and suffocation, in some cases leads to a lethal outcome. Poisonous spiders tarantulas of the sort Lycosa live in the South American countries with a humid climate. On site their sting there are extensive ulcerations, sometimes gangrene. In the countries of South and Central America are eurysynusic and from there spiders of the sort Phoneutria are quite often delivered to other countries with fruit, especially with bananas. They differ in extreme aggression, their poison on force of action is equal to poison of a cobra and is less toxic, than poison of a scorpion of the sort Tityus. Apply serums against poison of spiders of the sorts Lycosa and Phoneutria to treatment of victims of a sting of spiders.

Genetic anomalies (see. Hereditary diseases) are eurysynusic in many districts of tropics. So, at residents of the nek-ry regions of Africa the frequency of abnormal hemoglobin S reaches 40% (see the Sickemia). High frequency of this anomaly is the share, as a rule, of territories, hyper endemic on tropical malaria (see), edges as it is considered to be, was the selection factor for carriers of abnormal hemoglobin S. The weight of evidence suggests, as other mass genetic anomalies collected at inhabitants of tropics under the influence of malaria (e.g., deficit of a glyukozo-6-phosphate-dehydrogenase in erythrocytes).

Bibliogrvoprosa of medical parasitology, under the editorship of V. P. Podjyapolskaya and JI. I. Prokopenko, page 201, M., 1970;

The Guide to tropical diseases, under the editorship of A. Ya. Lysenko, M., 1983; E d i n g-t o n G. M. a. G i 1 1 e s H. M. Pathology in the tropics, L., 1976; Manson’s tropical diseases, ed. by Ch. Wilcocks a. P. Manson-Bahr, L., 1974; Service M. W. A guide to medical entomology, L., 1980; S e of at V. a. Mirovsky J. L£karstvi v tro-pech a subtropech, Praha, 1976; Tropical medicine, ed. by G. W. Hunter a. o., Philadelphia a. o., 1976. A. Ya. Lysenko.