Earlier this month, Massachusetts and California became the latest states to confirm human cases of the West Nile virus this year. West Nile virus outbreaks have been reported annually during the summer months since 1999 in all states except Hawaii and Alaska, so while the latest reports aren’t uncommon, they do demand the public’s attention.

There were samples taken in different areas of Riverside County, CA on the 11th and 12th of August that were all found to be positive for the virus.  In Massachusetts the first human infection of West Nile was confirmed in the Middlesex County. In Riverside the Riverside County Department of Environmental Health received the confirmation from the Vector-borne Disease Section at UC Davis, which tests mosquitoes collected in Murrieta, Temecula and Hemet that were positive.

West Nile virus was first detected in the United States in 1999 after an epidemic broke out in New York. The virus can be traced back to 1937, when scientists first associated the feverish, sickly symptoms of what is now known as West Nile virus with a Ugandan woman. There is currently no vaccine for the disease but officials note that 70 to 80 percent of infected people do not actually end up developing symptoms. Around one in five infected people develop symptoms like headaches, diarrhea and rashes, body aches, weakness and fatigue, that can last up to a few weeks or even months.

“We need to continue to take steps to protect ourselves against mosquito bites by using insect repellant, covering up, and reducing outdoor activities at dusk and after nightfall when mosquitoes are at their most active,” said DPH state public health veterinarian Dr. Catherine Brown. Many species of mosquito are native to wet, marshy areas, which is why the West Nile virus is common in the summertime, when many people are out swimming to cool off. It is important to remain cognizant of mosquitos to avoid being bitten and contracting the viruses they carry.

Learn more about how to protect yourself and your loved ones against mosquito bites by visiting westnile.ca.gov.