As the West Nile virus is found circulating among animals in and around Mechelen, the potential spread of the mosquito-borne illness among humans has raised concerns.
The Mechelen city council issued a warning on Saturday, stating that tests among horses and mosquitoes indicate that the virus is circulating in the area. It warned hospitals and doctors to take potential infections into account when diagnosing cases.
The Red Cross announced on Monday that it would start testing blood donors from the area around Vilvoorde, just outside of Brussels, for potential infections.
"We detected the first cases among birds last year," professor Hans Nauwynck, head of the Laboratory of Veterinary Virology at the University of Ghent, told the Brussels Times. "The virus primarily circulates among Corvids and birds of prey. Outside of birds, it only spreads to humans and horses. We have now seen cases with horses."
While the virus can be transmitted intra-humanly, the chances are very low. "In larger mammals, the virus is diluted within the blood. The chances of a mosquito being contaminated by biting a human are very low," Nauwynck explained.
"With blood transfusions, these chances increase significantly. As larger amounts of blood get transfused, the chances of an infection grow,” he said. “Testing people who donate blood is a good call in my opinion. One infection caused by a donation is one too many."
Hard to estimate the spread
Infections tend to be mild among humans: only one in four develop symptoms like headache, muscle pain and fever. In very rare cases, the virus can lead to meningitis and become potentially fatal.
Belgium’s Federal Government advises being more mindful of getting bitten by mosquitoes, especially among people who have preexisting health conditions and the elderly.
The virus has started spreading in Europe in recent decades, as warmer winters and drier summers allow for the mosquitoes carrying the virus to survive and multiply.
With the majority of infected people or animals not noticing the infection, it is hard to estimate the extent to which it has spread in Belgium.
"The most accurate approach would be to test for antibodies. If a horse or a human has antibodies, you know they have been infected at some point," Nauwynck said. "But I doubt that investment will be made."
A babbling brook
A vaccine exists and has been widespread. Albeit only for horses.
"We predicted the spread of the virus years ago. I have told everyone I have met who owns horses to get them vaccinated for a long time. With the current panic, the vaccine stocks might run out. There should be a push to get as many horses as possible vaccinated," Nauwynck said.
"As veterinarians, we are simply more advanced in treating this virus. Diagnostically and preventively. We understand the virus and have experience in dealing with it,” he said. “In humans, West Nile is primarily treated as if it is the flu, targeting symptoms. Only the neurological cases will require actual treatment."
According to Nauwynck, the virus does not warrant panic. "For us veterinarians, it is a babbling brook. We predicted it, are ready and not worried."
