Two Orange County residents have died of West Nile virus in the past week as the county's number of human infections has grown fivefold this month and appears to be "spiraling out of control," health officials said Thursday.
The county Health Care Agency reported 13 more West Nile infections in the past two days, bringing the total number of reported cases this year to 53. At the beginning of August, the year's total was nine, meaning 44 cases have been added this month.
An unidentified Huntington Beach man in his 70s died after contracting West Nile neuroinvasive disease, the most severe form of the mosquito-borne illness, according to the county Health Care Agency.
His death was reported a week after a Seal Beach woman in her 80s died after contracting the same disease. Underlying medical conditions also contributed to her death, officials said.
But the illness isn't discriminating by age – most of those infected are in their 30s to 50s; two are younger than 18. All but eight are male.
Seven people, three of them in Costa Mesa, have a form of the virus but do not show symptoms, which can include fevers, headaches, body aches, convulsions and muscle weakness, health officials said.
Thirty-seven people, including one in Costa Mesa, have the neuroinvasive form, which in some cases leads to neurologic illnesses like meningitis, according to the federal Centers for Disease Control and Prevention.
Cause of outbreak uncertain
Local officials said they're unsure what's causing the rapid increase in cases, though Jared Dever, director of communications for the Orange County Vector Control District, said the agency anticipated a potential outbreak in June after seeing growth in the number of West Nile-carrying mosquitoes since the beginning of the year.
"We knew that there were going to be some serious problems," said Huntington Beach Councilman Joe Carchio, who is vice president of the Vector Control District. "We were hoping that we had enough ammunition to bring it under control and curtail it as much as we could, but it seems like it's just spiraling out of control now."
West Nile spreads from birds to mosquitoes to people. The Vector Control District provides services aimed at protecting the public from pests including mosquitoes, rodents, flies and ants.
Carchio said he was surprised that the latest fatality, the 11th West Nile death in Orange County in a decade, occurred in Huntington Beach, where there had not been a reported human infection this year before the man's death.
Thirty-four of the county's cases are in Santa Ana and Anaheim. The disease also has been reported in Fullerton, Garden Grove, Laguna Niguel, Los Alamitos, Orange and Tustin, according to the Health Care Agency.
Vector Control said it has found 229 dead birds and 296 mosquitoes that tested positive for the disease.
By comparison, the Greater Los Angeles County Vector Control District this year has reported 12 human infections, seven dead birds and 120 mosquitoes carrying the illness.
While Orange County Vector Control has tried to slow the breeding of mosquitoes by placing fish in pools and ponds to eat their spawn, residents need to help control the West Nile outbreak, Carchio said.
"Maybe it's because we have a lot of pools that are not being maintained," he said. "You need to have the support of the communities. I think that people don't take it as serious as they should."
Dr. Michele Cheung, deputy medical director of epidemiology at the Health Care Agency, said there is no treatment for the illness.
Those experiencing severe headaches, confusion, neck stiffness, muscle weakness or vision loss should see a doctor immediately, she said.
Those with milder symptoms can take over-the-counter pain and fever medication and seek further attention, if the condition becomes worse, Cheung said.
Here are tips from the Health Care Agency and Vector Control District to help prevent mosquitoes from spawning and to protect yourself from bites:
• Empty all standing water on your property, including flower pots and bowls.
• Make sure windows and screens are in good condition.
• Use insect repellent containing DEET.
• Limit outdoor activity at dawn and dusk, when mosquitoes are most active.
• Wear long-sleeved shirts and long pants outdoors.