A new type of rabies was discovered this week by scientists at the University of Glasgow and the Animal Health and Veterinary Laboratories Agency (AHVLA).
The virus originated from the Serengeti National Park in Tanzania; a park that has been rabies-free since 2000.
What prompted the discovery was the 2009 attack from an unprovoked civet on a child who was visiting the park. The bite was promptly washed and cleaned, and the child given appropriate post exposure rabies vaccination. Rangers were contacted after the attack, and the civet, who had been displaying symptoms of rabies, was killed. Scientists at the Central Veterinary Laboratory in Tanzania tested brain samples from the civet and noted the presence of lyssavirus-specific antigens.
Lyssaviruses are those responsible for rabies-like diseases in animals. When an animal has lyssavirus-specific antigens present, the animal’s immune system is emitting antibodies to fight a particular pathogen. In this case, as the antigens indicated, the pathogen is a lyssavirus, which means the civet was rabid. The AHVLA confirmed these results and conducted further analysis showing that the virus was actually a novel type of rabies.
Rabies belongs to the lyssavirus family. In this family, eleven different lyssaviruses have been classified, and two relatively new viruses have been identified. The difference between the two (classification and identification) is that classification involves identifying a group of organisms that shares common properties and is different from other groups of organisms, whereas identifying an organism means that said organism is placed within a classification. In other words, classification tells us how an organism is related to other organisms, where as identification is assigning an organism a specific identity (perhaps assigning it to a group or class).
What was peculiar about these samples was that they did not match samples from other classified and identified rabies viruses. Scientists tested the civet samples against all different lyssavirus species and found no match.
The scientists from the University of Glasgow are calling the new lyssavirus Ikoma lyssavirus, or IKOV.
This discovery was extremely surprising for scientists as there has been no rabies present in the park, or within a 30km radius, for over a decade. Further, because this is a new virus, scientists cannot confirm whether the treatment the child received is effective against IKOV. To date, the child is well.