I'm an incidental host, I swear!
This week the CDC’s Emerging Infectious Disease journal published a study showing evidence of a novel lyssavirus detected from brain samples of an African civet in the Serengeti ecosystem of Tanzania.
What does this mean? Well, essentially an African civet displaying rabies like symptoms was shot by Serengeti National Park (SNP) rangers in May of 2009, after the civet had bitten a child in an unprovoked attack. Because SNP implements a rabies control program, park rangers were trained to take samples of the civet for analysis. Brain tissue is the best sample type for detecting rabies virus, so a portion of the civets brain was taken to the Central Veterinary Laboratory in Dar es Salaam.
At the lab, scientists extracted RNA from the samples, and then with colleagues at the Animal Health and Veterinary Laboratories Agency in the UK, detected a novel strain from the lyssavirus family using molecular techniques (e.g. pan-lyssavirus reverse transcriptase PCR). The new virus, called Ikoma Lyssavirus (IKOV), is highly divergent from rabies virus, though the civet’s behavior indicates it can cause rabies-like symptoms. The child was treated with the post-exposure rabies vaccination and given wound care, and at the time of the report was well. However, it is not known if the vaccine is effective against the new virus.
Phylogenetic relationships of all currently identified lyssavisures compared with Ikoma lyssavirus from the African civet.
This was the first detected case of rabies in SNP since 2000, but because the civet was infected with a novel lyssavirus, it is not considered a breach in the rabies control program. Also, because lyssaviruses like rabies are infrequently detected in civets, it is assumed the animal was acting as an incidental host, which means that it was most likely infected through another animal, perhaps a bat. This study demonstrates the importance of wildlife surveillance for public health, and projects like HALI working through the PREDICT project of USAID’s Emerging Pandemic Threat program, are investigating wildlife, including bats, to better understand what viruses are circulating in wildlife and how best to prevent human exposure and respond to potential outbreaks.
To learn more about HALI’s role in the PREDICT project, feel free to contact the HALI team.