Yellow fever

General characteristic of a disease

Yellow fever represents acute hemorrhagic (followed by hemorrhage) the disease having a virus etiology.

Sources of infection with this virus are wildings, usually opossums and monkeys, and also people sick with them. As carriers of the causative agent of yellow fever serve mosquitoes while directly from the person to the person the virus is not transmitted. This disease is local in Latin America and tropical area of Africa.

By estimates, in the world annually this virus affects about 200 thousand people from whom for 30 thousand the outcome of a disease has lethal character. For the last twenty years the tendency of increase in cases of infection with yellow fever is observed that is caused by decrease in immunity of the population, an urbanization, deforestation, population shift and climate change.

The most effective prevention of a disease is the yellow fever inoculation today.

Disease symptoms

The virus of yellow fever is in an incubation interval about 3-6 days then the infection begins to be shown.

The disease can have one or two stages. Temperature increase, a fever, pain in a waist, muscular pains, a headache, appetite loss, vomiting or nausea are characteristic of the first stage.

For most of patients the disease is limited only to this stage – in 3-4 days symptoms of yellow fever pass. However in 15% of cases in a day after remission of patients the second stage, more toxic, than previous expects. At this stage body temperature rises again, there is a defeat of systems of an organism, jaundice in high gear begins to develop, the patient suffers from vomiting and pain in a stomach.

Bleedings from a nose, a mouth, eyes become characteristic symptoms of yellow fever at this stage. The gastromenia which is shown in the form of availability of blood in excrements and vomiting is possible. Besides, at this stage of a disease there is a deterioration in function of kidneys. About 50% of the patients who faced a toxic stage of a disease die in 10-14 days, and the others in most cases recover without essential defeats of bodies. Disease complications in the form of pneumonia, myocarditis, gangrene of extremities or soft tissues are only sometimes possible. The development of sepsis caused by accession of a secondary bacterial flora is also possible.

Symptoms of yellow fever are similar to symptoms of heavy malaria, a hay fever, viral hepatitis, other hemorrhagic fevers, poisonings therefore it is very difficult to diagnose this disease. Only highly skilled medics by carrying out laboratory researches of samples of blood or posthumously taken hepatic fabric can reveal a virus of yellow fever.

Treatment of yellow fever

Specific drugs are not developed for treatment of yellow fever today therefore only symptomatic therapy of a disease is possible.

Patients are recommended to observe a bed rest and to keep to the sparing diet rich with high-calorific products. Treatment of yellow fever assumes massive vitamin therapy, use of non-steroidal anti-inflammatory drugs (except acetylsalicylic acid), infusional administration of plasma substitutes and the adsorbing drugs. At the expressed bleedings hemotransfusion can be appointed.

Prevention of a disease

The yellow fever inoculation represents the most important and efficient way of prevention of this disease. Vaccination is necessary not only to the tourists living in local areas, but also leaving to those regions.

The certificate on an inoculation from yellow fever is necessary for all persons making trips to Africa or Latin America. If on medical indications vaccination is contraindicated to the person making a trip, release from it has to be certified by competent authorities.

The vaccine against yellow fever containing the weakened virus allows within a week at 95% vaccinated to develop reliable immunity to a disease which remains for 30-35 years, and sometimes and for life. In spite of the fact that the vaccine is recognized as one of the most highly effective and safe in the history of a vaktsinologiya, the yellow fever inoculation and contraindications has. This vaccine is not intended for:

• 9 months in case of carrying out regular immunization are younger than children;
• 6 months on condition of epidemic are younger than children;
• pregnant women – an exception disease outbreaks are;
• the persons having a heavy allergy to ovalbumin;
• persons with the heavy immunodeficiency caused by symptomatic HIV / AIDS either other reasons, or the suffering thymus diseases.

The infected person, even at an easy form of yellow fever, represents danger to people around therefore to prevent further spread of a virus, provide to the patient the maximum protection against stings of mosquitoes. Isolation of the patient is reasonable only in the first 4 days as later he does not represent an infection source for mosquitoes any more.

Nonspecific way of prevention of yellow fever is the fight against mosquitoes including destruction of breeding grounds of these insects, spraying of insecticides for destruction of adult individuals and also addition of these chemical drugs in water sources in which mosquitoes begin the development.