Rift Valley Fever arrives

There have been cases of Rift Valley Fever reported in Uganda. This is not the first time that the virus has been in East Africa. It has been known to be in the region for about the last century. Where or when it will show up is not known. It arises sporadically, as if watered by floods or heavy rains. When water arrives, the virus sometimes blossoms - if there's the right mix of farming animals, mosquitoes, and people over a long period of time.

Want to find out more about the basics of Rift Valley Fever? Click here.

How can people get sick?

People can get sick from being associated with sick animals. This doesn't mean, though, that they touched a sick animal.

Some people become sick through contact with blood, body fluid, organs, and other tissues of infected animals. This can be from slaughter, butchering, veterinary work, or helping an animal give birth.

It's possible that these fluids can spray in the air and spread airborne, as they have been found to have done in laboratories.

There has not been any evidence of the infection from spreading from one infected person to another person, however. There is concern though that the infection could be transmitted to caregivers from patients, but, if so, the risk is very low.

On the other hand, sometimes, the association with infected animals can be pretty far removed. The virus can spread also through mosquitoes, or some other biting flies or insects, that have been contaminated with infected blood (that had been in an infected animal).

There are several different mosquito species that can be responsible. These can include different types of Aedes mosquitoes and sometimes Culex mosquitoes. The lifecycles of the mosquitoes and their interactions with animals and people help determine when outbreaks happen. 

Mosquito spread of the virus thought to be the reason why flooding and rainfall appear to be associated with large RVF outbreaks.The virus is transmitted from female mosquitoes to offspring and the virus remains infectious inside the egg - even for several years and during dry times.

Rainfall leads to more eggs hatching. The mosquitoes are then hungry and look for meals from animals and humans. As such, outbreaks are often sporadic.

What sort of illness do animals face?

RVF causes bad liver disease, bloody diarrhea, and miscarriages in animals. Many die. Most young animals die. Most adults live, but many die (maybe 1 in 4, 1 in 5). Many, often most, pregnant animals miscarry. Different types of animals are more likely to get sick - and more likely to get really sick. Sheep are more likely to get sick than cows; cows more than camels.

How is it treated?

There is no specific treatment. Care involves IV fluid, oxygen, and other supportive care as needed, for seriously ill patients.

Is there a vaccine?

Sort of. There is a vaccine (inactivated, no live virus) and a live vaccine as well. There is not a vaccine licensed for use. Vaccines have been used experimentally for those people who work in labs or in veterinary work that may expose them to the virus.

There is hope that vaccinating animals may reduce spread.

Where is Rift Valley Fever found?

Well, not surprising, Rift Valley Fever was first found in the Rift Valley in Kenya. It was reported in livestock in the 1910's by veterinary officers. The virus was first identified in 1930.

Rift Valley Fever (RVF) is normally found in eastern or southern Africa, where there's sheep and cattle farming. The virus can also be found in many parts of Africa, reaching to west Africa and even Madagascar off the coast of Africa, but some areas where the virus spreads in animals have not seen any notable human outbreaks.

It was first identified outside of Africa in 2000. It was found in animals in Saudi Arabia and then Yemen.

What sort of virus is it?

RVF virus is in the genus Phlebovirus and the family Bunyaviridae. The Bunyaviridae are negative-stranded, enveloped RNA viruses and include Hantavirus and Crimean-Congo Hemorrhagic Fever.

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