Yellow fever

The yellow fever , sometimes called black vomit ( vomito negro ) or American plague , is a acute Viral disease. It remains always an important cause of hemorrhagic diseases in several African and South American countries, in spite of the existence of a effective Vaccin.

History

1965 - several thousands of case causing several hundreds of died with the Senegal
1978 - 91 died in Bolivia, Ecuador, Brazil, Colombia, Peru and Venezuela
1978 - 63 died in Gambia
1978 - 40 died with the Ghana

Whereas 206.000 cases of yellow fever were listed in 2005 in twelve African countries (Bénin, Burkina Faso, Cameroun, Ivory Coast, Ghana, Guinea, Liberia, Mali, Nigeria, Senegal, Sierra Leone and Togo), causing 52.000 deaths, the the World Health Organization estimates that the epidemic will be able to make between 1,5 and 2,7 million deaths if nothing is done as regards vaccine prevention.

Epidemiology

The disease is caused by a Arbovirus of the family Flaviviridae (which also includes/understands the Dengue, the Encéphalite of Saint Louis and the Virus of the Western Nile). It is one of smallest the Virus with ARN than one succeeded in isolating at the man.

The Moustiques are the principal vector of the disease by transmission of the monkeys to the man and transmission of man with man. The implied mosquitos are Aedes simpsoni , Aedes africanus , and Aedes aegypti in Africa, as well as the Haemagogus and Sabethes . There is a difference between the symptoms of the disease in rural sectors and the cities. The symptoms of the disease in the cities and at the people of foreign origin are usually more serious.

Physiopathology

Puncture Aedes => VIRUS => blood
Multiplication in ganglia => blood
Liver, spleen, kidneys

Diagnosis

After one incubation period from 3 to 6 days, the typical symptoms which appear are the fever, of the muscular pains, the headaches and the back pains. The red language, the livid face and the reddening of the eyes can also be symptoms of the disease. In certain cases, internal bodies such as the liver, the kidneys and the heart can be touched. There can be a hemorrhage of the digestive tract: the subject vomits black blood then (the characteristic vomito negro ).

Assumption of responsibility

There does not exist treatment, this is why the protective inoculation is so important. One can only treat the symptoms of the disease and support the patient, in particular by réhydratant it. Heavier actions are necessary for the most serious cases, like blood transfusions or dialyzes.

Evolution and complications

The majority of the patients see their state improving at the end of three to four days. However in 15% of the cases, the disease develops towards a more serious, sometimes complicated form by a Ictère due to a failure of the liver and/or an impaired renal function caused by a Protéinurie. If the disease progresses, the subject is delirious and fall into the coma. Hypotension and dehydration are also current. The yellow fever is mortal in 50 to 80% of the serious cases. Death occurs 6 to 7 days after the beginning of incubation.

Prevention

A vaccine against the yellow fever was developed: it gets a ten years immunity and protects the people effectively travelling in the sectors affected by the disease while being a means of controlling the expansion of the disease. The insecticides, clothing protective and the installation of Moustiquaires on the houses are individual measurements useful, but not always sufficient, against this disease. Eradication campaigns of the mosquitos in the affected areas also make lower the number of cases.

In much of country, the people who visited in the last six months of the countries touched by the yellow fever and which do not have material proof of vaccination are likely to be placed in quarantine until one could check that they are not carrying the disease.

Obligatory declaration

In France, in Belgium, and Germany, this disease is on the list of the Infectious illness to obligatory declaration

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