The Greater Los Angeles County Vector Control District has confirmed the spread of West Nile Virus to four communities. The group confirmed that signs of the disease have been detected in the Carson, Northridge, Reseda, and Signal Hill neighborhoods.

According to local reports, residents of these areas are being urged to use the proper EPA-approved repellents when spending time outside to avoid exposure to mosquitos. This is especially important currently, as summer heat can increase mosquito populations. West Nile is passed to humans through mosquitos, which pick it up from birds.

“People over 50 years of age and those with certain medical conditions are at increased risk of serious complications from WNV infection,” the Orange County Health Care Agency said in a press release, according to the Orange County Register.

There have 10 West Nile Virus human cases reported in California in 2019. 

Two Los Angeles County residents were reported to have been infected with the mosquito-borne West Nile virus in July and were recovering. 

Traces of West Nile were first discovered in Orange County as well, as mosquitos and dead birds found in Cypress, Buena Park, Huntington Beach and Tustin tested positive for the virus.

Earlier this week, a Tustin woman in her 50s was diagnosed with the first human case of West Nile in Orange County in 2019. In 2018, 12 people were diagnosed with the virus in Orange County and resulted in one death.

Symptoms of West Nile may include fever, nausea, fatigue and rashes, with more serious cases causing confusion, paralysis, and weakness. Most with the virus will exhibit no symptoms, however.