Arboviruses Health Dictionary

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Arboviruses: From 1 Different Sources

A heterogenous group of around 500 viruses, which are transmitted to humans by ARTHROPODS. Grouped in four families, they include the viruses of DENGUE and YELLOW FEVER which are transmitted by mosquitoes.
Health Source: Medical Dictionary
Author: Health Dictionary

Arthropods

Arthropods are segmented invertebrates with jointed legs. They include a wide range of organisms, such as scorpions, mites, ticks, spiders and centipedes (see also ARBOVIRUSES).... arthropods

Yellow Fever

An acute arbovirus (see ARBOVIRUSES) infection caused by a ?avivirus of the togavirus family, transmitted from animals to humans by various species of forest mosquito (jungle/sylvan yellow fever), and from human to human by Aëdes aegypti (urban yellow fever). Mosquito transmission was shown by Walter Reed and his colleagues in 1900. It is ENDEMIC in much of tropical Africa and Central and South America but does not occur in Asia. In the urban cycle, humans constitute the reservoir of infection, and in the jungle/sylvan variety, mammals – especially subhuman primates – are involved in transmission. Historically, yellow fever was enormously important, causing devastating epidemics (see EPIDEMIC); it also carried a high mortality rate in travellers and explorers. Differentiation from other infections associated with JAUNDICE was often impossible.

Clinically, yellow fever is characterised by jaundice, fever, chills, headache, gastrointestinal haemorrhage(s), and ALBUMINURIA. The incubation period is 3–6 (up to 10) days. Differentiation from viral hepatitides, other viral haemorrhagic fevers, severe Plasmodium falciparum malaria, and several other infections is often impossible without sophisticated investigative techniques. Infection carries a high mortality rate. Liver histology (biopsy is contraindicated due to the haemorrhagic diathesis) shows characteristic changes; a fulminating hepatic infection is often present. Acute in?ammation of the kidneys and an in?amed, congested gastric mucosa, often accompanied by haemorrhage, are also demonstrable; myocardial involvement often occurs. Diagnosis is primarily based on virological techniques; serological tests are also of value. Yellow fever should be suspected in any travellers from an endemic area.

Management consists of instituting techniques for acute hepatocellular (liver-cell) failure. The affected individual should be kept in an isolation unit, away from mosquitoes which could transmit the disease to a healthy individual. Formerly, laboratory infections were occasionally acquired from infected blood samples. Prophylactically, a satisfactory attenuated VACCINE (17D) has been available for around 60 years; this is given subcutaneously and provides an individual with excellent protection for ten years; international certi?cates are valid for this length of time. Every traveller to an endemic area should be immunised; this is mandatory for entry to countries where the infection is endemic.... yellow fever

Alphavirus

n. any member of a genus of *arboviruses transmitted by mosquitoes. Many alphaviruses can cause disease in humans and animals, including *O’nyong nyong fever and *Ross River fever.... alphavirus

Dengue

(breakbone fever) n. a disease caused by arboviruses and transmitted to humans principally by the mosquito *Aëdes aegypti. Symptoms, which last for a few days, include severe pains in the joints and muscles, headache, sore throat, fever, running of the eyes, and an irritating rash. These symptoms recur in a usually milder form after an interval of two or three days. Death rarely occurs, but the patient is left debilitated and requires considerable convalescence. A more severe form, dengue haemorrhagic fever, characterized by a breakdown of the blood-clotting mechanism with internal bleeding, can affect children. Dengue occurs throughout the tropics and subtropics. Patients are given aspirin and codeine to relieve the pain and calamine lotion is helpful in easing the irritating rash.... dengue

Flavivirus

n. any member of a genus (and family) of *arboviruses that cause a wide range of diseases in vertebrates (including humans). Transmitted by ticks or mosquitoes, these include *yellow fever, *dengue, *Kyasanur Forest disease, *Russian spring-summer encephalitis, and *West Nile fever.... flavivirus

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