The LA County Department of Public Health announced its first case of West Nile virus this year. An Antelope Valley resident has been hospitalized with a rare and serious form of the virus.
On Monday, the Los Angeles County Department of Public Health said a person currently infected was hospitalized after developing West Nile virus encephalitis — which can cause fever, altered mental status and movement disorders, according to the Centers for Disease Control and Prevention. It occurs in less than 1% of infected patients.
“Finding West Nile virus in our region is a reminder that this virus has been present in California, and right here in our community, for over 20 years,” said Brenna Bates-Grubb, public relations specialist for the Antelope Valley Mosquito and Vector Control District.
The mosquitoes that carry the virus and the diseases it carries are “part of our environment and continue to evolve year after year,” Bates-Grubb said in a statement.
West Nile virus is the most common and dangerous mosquito-borne disease in California with no specific treatment or vaccine to prevent infection.
Last week, local and state public health officials reported that West Nile virus activity is above average for this time of year. By the end of June, there were at least 48 cases of human disease across the country, including 38 cases of severe neuroinvasive disease.
There have been three reported human cases of West Nile virus in the state so far this year — a case announced Monday by health officials in Los Angeles County, one in Sacramento County and one reported by the city of Long Beach.
The Los Angeles Department of Public Health reports 41 human cases a year, on average, over the past five years, officials said.
“However, the number of people infected with West Nile virus each year in LA County is very high as the majority of people infected with the virus are either asymptomatic or mildly ill,” the department said in a statement.
Anyone is at risk of contracting the virus, but those most at risk of serious illness and long-term complications include people over 50 and those with pre-existing conditions.
Most of the people who get infected with this virus do not show any symptoms. Some will experience mild symptoms such as fever, body aches and nausea.
In severe cases, symptoms include high fever, headache, neck stiffness, vision loss, paralysis and coma. These more severe symptoms can last for several weeks and lead to permanent damage to the brain and nervous system.
LA County officials said the first human case is an important reminder to the public that everyone needs to take steps to prevent mosquito bites and breeding.
How to avoid mosquito bites
- Apply mosquito repellent directly to all exposed skin. The repellent must contain at least one of the following active ingredients: DEET, IR3535, oil of lemon eucalyptus or Picaridin/KBR 3023.
- Wear a long-sleeved shirt and long pants when outside, especially in the morning and evening.
- If you can, avoid being outside between dusk and dawn, which is when mosquitoes that spread West Nile virus are most active.
How to prevent mosquitoes from breeding in your home
The best way to prevent infection is to make sure your home is not a breeding ground for mosquitoes that carry the virus.
- Remove standing water near homes, and remove containers that may catch and hold water.
- Empty or change the water in pet bowls, birdbaths and other outdoor containers at least once a week.
- Clean and chlorinated swimming pools; remove any water that collects on pool covers.
- Install or repair door and window screens.
- Garden ponds are stocked with mosquito fish (aka Gambusia affinis), goldfish, Koi or other mosquito-eating fish. These eat mosquito eggs and larvae.
- Support local mosquito prevention efforts by reporting neglected swimming pools, large mosquito breeding sites or unusually high mosquito infestations to the County Animal Control Department; The LA County agency offers many tips and mosquito removal services.
- Report dead birds to the Vector Control District; it's one way officials can track where the West Nile virus is spreading. West Nile virus is transmitted to birds by the bite of an infected mosquito, and mosquitoes can become infected by the bite of an infected bird.
