Arbovirosis

December 31, 2014

Synonyms

Overview

An infectious disease caused by an arbovirus. The word arbovirus is an acronym (ARthropod-BOrne virus). The word tibovirus (TIck-BOrne virus) is sometimes used to describe viruses transmitted by ticks, a superorder within the arthropods. The virus is transmitted by arthropods such as insects and ticks. Examples of arboviruses include Yellow Fever, Japanese encephalitis and tick-borne encephalitis.

The symptoms may vary depending on the type of virus involved. Symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last 3 or 4 days. The most common clinical features of infection are fever, headache, and malaise, but encephalitis and hemorrhagic fever may also occur. The infection can lead to life-threatening brain inflammation.

Symptoms

Chills
Tiredness
Aching muscles
Asymptomatic
Fever
Headache
Vomiting
Drowsiness
Irritability
Nausea
Confusion
Weakness
Stiff neck
Seizures
Encephalitis
Meningitis
Paralysis
Rash
Hemorrhagic fever
Arthritis
Central nervous system symptoms

Prevention

Vector control measures, especially mosquito control, are essential to reducing the transmission of disease by arboviruses. Habitat control involves draining swamps and removal of other pools of stagnant water (such as old tires, large outdoor potted plants, empty cans, etc.) that often serve as breeding grounds for mosquitoes. Insecticides can be applied in rural and urban areas, inside houses and other buildings, or in outdoor environments. They are often quite effective for controlling arthropod populations, though use of some of these chemicals is controversial, and some organophosphates and organochlorides (such as DDT) have been banned in many countries. Infertile male mosquitoes have been introduced in some areas in order to reduce the breeding rate of relevant mosquito species. Larvicides are also used worldwide in mosquito abatement programs. Temefos is a common mosquito larvicide.

People can also reduce the risk of getting bitten by arthropods by employing personal protective measures such as sleeping under mosquito nets, wearing protective clothing, applying insect repellents such as permethrin and DEET to clothing and exposed skin, and (where possible) avoiding areas known to harbor high arthropod populations. Arboviral encephalitis can be prevented in two major ways: personal protective measures and public health measures to reduce the population of infected mosquitoes. Personal measures include reducing time outdoors particularly in early evening hours, wearing long pants and long sleeved shirts and applying mosquito repellent to exposed skin areas. Public health measures often require spraying of insecticides to kill juvenile (larvae) and adult mosquitoes.

Vaccination:
Vaccines are available for the following arboviral diseases:

Japanese encephalitis
Yellow fever

Vaccines are in development for the following arboviral diseases:

Dengue fever
Eastern Equine encephalitis
West Nile

Diagnosis

Preliminary diagnosis of arbovirus infection is usually based on clinical presentations of symptoms, places and dates of travel, activities, and epidemiological history of the location where infection occurred.

Definitive diagnosis is typically made in a laboratory by employing some combination of blood tests, particularly immunologic, serologic and/or virologic techniques such as;

ELISA
Complement fixation
Polymerase chain reaction
Neutralization test
Hemagglutination-inhibition test

Treatment

Because the arboviral encephalitides are viral diseases, antibiotics are not an effective form of treatment and no effective antiviral drugs have yet been discovered. Treatment is supportive, attempting to deal with problems such as swelling of the brain, loss of the automatic breathing activity of the brain and other treatable complications like bacterial pneumonia.

Aspirin and ibuprofen should not be taken in cases of dengue fever as it could increase the risk of bleeding and cause Dengue Shock Syndrome.