EBOLA


Ebola Virus Image Tables and Charts:


AGENT
Ebola virus is a member of the virus family Filoviridae.

There are at least four subtypes of Ebola virus: the original strain isolated from Zaire in 1976 and subsequently reappearing in 1995; a subtype isolated from Sudan in 1976 and again in 1979; "Reston" subtype isolated from monkeys imported into the United States from the Philippines in 1989, and later from similar monkeys imported into Italy and from the original shipping source of the monkeys in the Philippines; and a newly discovered subtype isolated from Côte d'Ivoire in 1994.

DESCRIPTION
The Ebola virus is one of the most pathogenic viruses known to science, causing death in 50-90% of all clinically ill cases.

TRANSMISSION
By direct contact with the blood, secretions, organs, or semen of the infected person. Transmission by semen may occur up to seven weeks after recovery. Health care workers are frequently infected while caring for the ill or dead patient. It can be transmitted by infected needles.

The natural reservoir of the Ebola virus is not known. Extensive ecological studies are currently underway in Côte d'Ivoire, Gabon and Zaire to identify the reservoir. Ebola-related filoviruses were isolated from cynomolgus monkeys (Macacca fascicularis) imported into the United States of America from the Philippines in 1989. A number of the monkeys died and at least four persons were infected, although none of them suffered clinical illness.

SYMPTOMS
Ebola haemorrhagic fever is often characterized by the sudden onset of fever, weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, limited kidney and liver functions, and both internal and external bleeding.

INCIDENCE AND DISTRIBUTION
Outbreaks have occurred in Sudan, Zaire Côte d'Ivoire, and the United States of America. First identified in a western equatorial province of Sudan and in a nearby region of Zaire in 1976. The most recent outbreak was in rural Gabon in February 1996. See chart of reported cases.

TREATMENT
No specific treatment or vaccine exists for Ebola haemorrhagic fever. Severe cases require intensive supportive care, as patients are frequently dehydrated and in need of intravenous fluids. Experimental studies involving the use of hyperimmune sera on animals demonstrated no long-term protection against the disease after interruption of therapy.

PREVENTION
Suspected cases should be isolated from other patients and strict barrier nursing techniques practised. any person who has had close physical contact with patients should be kept under strict surveillance, i.e. body temperature twice a day

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