On Wednesday, Madison County Department of Public Health officials announced that the West Nile virus has been found in Edwardsville. For now, it is not clear whether the virus was detected in mosquitoes or in a dead animal.

Officials were of the view that this summer, the virus was also detected in the metro-east. Mosquitoes were tested positive in Belleville, O’Fallon and Waterloo. As per Illinois Department of Public Health, the virus has been detected in 24 Illinois counties.

For now, there have been no human cases recorded. The officials have affirmed that five dead birds and 117 batches of mosquitoes were tested positive for the virus. Colorado health officials have been adopting precautions. They have warned livestock owners to take all the measures during the summer months.

Extra cautiousness is needed because Colorado’s first case of West Nile virus has been confirmed in Boulder County. The State Veterinarian's Office has warned that equine owners should keep a close check on their properties for insects. The virus has also been detected in Mesa County.

Experts have even asked to not keep standing water from recent rain, as it can become a breeding ground for mosquitoes that carry the insects. “The best to protect them is vaccinate them. That way if they get bit, it doesn't really matter because the vaccine is gonna protect them”, said equine veterinarian John Harris.

The transmission of the disease changes year to year and it depends on many factors like mosquito numbers.