New Important Discoveries about Foot and Mouth Disease

Foot-and-mouth disease is a viral illness that is highly contagious, affecting both wild and domestic cloven-hoofed animals like sheep, goats, antelopes, pigs, and bison. This disease is one of the most common and deadliest livestock diseases with reports on its global outbreak, especially in Africa, Asia, South America, and the Middle East.

FMD is caused by a virus that comes in seven different serotypes; A, O, C, Asia1, SAT1, SAT2, and SAT3, which are endemic. It is important to be able to distinguish the serotypes of this virus because it makes vaccination much easier; protection from one serotype doesn’t cover for the protection from others.

This viral disease is known to spread rapidly among animals; humans are incapable of hosting the Foot-and-mouth disease virus (FMDV). The presence of just one infected animal gives a signal that every other animal around is either infected or is at risk of being infected. Especially in cases where animals are closely housed together.

FMDV can be easily transmitted, affecting neighbouring animals very quickly. Direct contact with an infected animal, contaminated fodder, and inhalation are the easiest ways animals can get infected. Transmission becomes faster through the movement of infected animals with pigs being a fast transmitter of this disease, excreting a large quantity of this virus in their exhaled breath.

Symptoms are most likely to surface between 24 hours to ten days of infection and might even take longer. Infection occurs when particles of the FMDV (picornavirus), is transported into the cell of the host. Fever, blisters in the mouth causing the secretion of foamy saliva that would lead to drooling, weight loss, reduced milk production, lameness and swollen testicles in infected male animals. These symptoms are hard to notice in sheep, making it more difficult to curb this disease.

There is no known cure for the FMD disease and vaccination can only go so far as to protect animals from this disease. A new system used by FMDV to avoid antiviral signalling of infected cells has been discovered by scientists at the Pirbright Institute in collaboration with the MRC Laboratory of Molecular Biology and other research institutes.

Being able to distinguish between infected and vaccinated animals is a smart step to containing this virus. Research on a Novel Biomarker that could be used to make this distinction has been published in Proceedings of the National Academy of Sciences.

The reproduction of virus-infected cells could be prevented through the deploying of an antiviral protein known as ISG15, which attaches to the FMDV. Lbpro, a protein encoded in FMDV has been discovered to allow the virus to continuously reproduce without any obstructions by stopping the actions of ISG15. When the actions of ISG15 is stopped, small parts of the protein are left behind (a GlyGly motif), making it easier for scientists to detect that an animal is infected.

FMD in animals has negatively affected the government and farmers, the loss of livestock and the inability of countries to trade. The provision of a more accurate method of determining if livestock is infected would create a better trading system for vaccinating countries.