Although September is known as the end of mosquitoes season that does not necessarily mean the threat of West Nile infection is over. The risk is still higher, the authorities warn, as the days get shorter and nights become longer giving mosquitoes the possibility to be more active, which might translate into more cases of West Nile infections.

The US Centers for Disease Control and Prevention has received reports of 413 cases of West Nile virus including five deaths from the infections, one in Arizona, and the other in Mississippi, two in California and the fifth in New York. However, the number of people infected with the virus could be much higher because the state and local governments need some time to file reports to the agency.

“Of the 413 cases, 180 (44%) were reported as West Nile meningitis or encephalitis (neuroinvasive disease), 219 (53%) were reported as West Nile fever (milder disease, and 14 (3%) were clinically unspecified at this time,” the CDC said.

Humans get contaminated with the West Nile virus through mosquito bytes which previously got it by feeding on infected birds. However, the virus cannot be transmitted from birds to man.

Although most people who are infected have no symptoms or seem to have a mild flu, the “classic” symptoms include a fever and headache, body aches and sometimes a rash and swollen lymph glands. Sometimes the infection turns into a neuroinvasive disease known as West Nile meningitis that puts patients into a near-coma state.

People have been warned to take adequate precautions in order to reduce the risk of mosquito bites. Eliminating standing water where the insects can breed, staying away from mosquito-infested areas, mending damaged window screens and doors, wearing trousers and long-sleeved shirts or applying mosquito repellant when leaving the house are several pieces of advice one must take into account, health officials say.