The word “arbovirus” is an acronym for “arthropod-borne virus”, which describes a virus that comes from arthropods.

More than a million different arthropods, that is more than 80 % of all described living animal species, have already been described by scientists − and there may be millions more out there. Arthropods include mosquitoes, spiders, ticks, sandflies, mites, millipedes, centipedes, crabs, lobsters, crayfish and shrimps. More than a 100 arboviruses are known.

The following arboviruses are found in Africa: West Nile, sindbis, yellow fever, dengue, chikungunya and Rift Valley.

What happens?

An arbovirus lives inside a host (eg birds or monkeys). An arthropod (eg a tick, mosquito or sandfly) feeds on the host and now carries the virus, thus becoming the vector. This vector transfers the virus to other organisms by feeding on their blood. In turn the newly infected organism now becomes a host for the virus … and thus the cycle continues. However, humans are not good hosts because arboviruses usually cannot thrive in the human body and usually humans cannot transfer the viruses to other humans.

Symptoms

The symptoms of an arbovirus infection generally occur within three to five days (but in some cases up to 15 days) after exposure to the virus and last for three to four days. The symptoms range from acute slight fevers of short duration to serious viral fevers where bleeding occurs and death. The most common symptoms of infection are fever, headache, rash and feeling unwell.

Prevention

Apart from environmental campaigns to eradicate vectors such as mosquitoes, the only way of preventing arbovirus infection is to prevent being bitten by the vectors in the first place. The following tips will help:

    • Wear clothing with long sleeves and cover your ankles – especially at dawn and dusk when mosquitoes are most active.
    • Apply insect repellents directly to the skin.
    • Use long-lasting insecticide sprays inside homes and buildings.
    • Use mosquito netting over the beds – they can also be soaked in certain types of insecticide.
    • Treat blankets and even clothing with insect repellents.
    • Place wire or gauze screens on all doors and windows.
    • Keep a fan on in the room during the night – the current seems to ward off the mosquitoes.
    • Spend evenings indoors rather than outdoors – you are much less likely to get bitten by mosquitoes.
    • Get rid of discarded tires, cans or plastic containers left outside that may contain standing water.
    • Turn over plastic wading pools and wheel barrows when not in use so that the water cannot gather in them.
    • Regularly drain standing water from your pool or hot tub cover.
    • Replace the water in bird baths, pet dishes and wading pools every three to four days.
    • Keep drains, ditches and culverts clean of trash and weeds so water will drain properly.
    • Clean the gutters to ensure they drain properly.
    • Where appropriate, get a vaccine before visiting an area where there is an arbovirus outbreak, for example of yellow fever.

 

Sources

https://en.wikipedia.org/wiki/Arbovirus
https://www.dhs.wisconsin.gov/arboviral/index.htm
http://www.medicinenet.com/script/main/art.asp?articlekey=16556
Prinsloo, B. Arboviral diseases in southern Africa. SA Fam Pract 2006:48(8).
Retrieved from http://www.safpj.co.za/index.php/safpj/article/view/665/579
Rautenbach, PGD. Mosquito-borne viral infections in southern Africa: a public health perspective. Retrieved from ttp://cmej.org.za/index.php/cmej/article/viewFile/2103/1794