In response to New Jersey’s first reported fatality associated with West Nile virus (WNV) and an increase in the number of cases from eight to 15 statewide, health officials have gone into high gear in an attempt to inhibit the spread of the disease.
Air surveillance and multiple environmentally friendly strategies — along with pesticides — have been added to the available responses, according to the New Jersey Department of Health. WNV is part of a family of viruses that can be transmitted by the bite of an infected mosquito.
“West Nile Virus cases tend to increase in late summer and fall, and residents should take steps to prevent mosquito bites,” said New Jersey Department of Health Commissioner Mary E. O’Dowd.
O’Dowd added that the majority of individuals infected with WNV will show no symptoms, while others will have mild to moderate symptoms, which may include fever, headache, rash, fatigue, nausea, vomiting, and swollen lymph nodes. “Symptoms appear within two to 15 days of being bitten by an infected mosquito. Older adults and immune-compromised individuals are at higher risk of developing severe illness,” O’Dowd said.
Testing, surveillance, and spraying efforts in New Jersey are coordinated between the state health department and counties.
Testing Mosquitoes for WNV
Greg Williams, superintendent of the Hudson County Mosquito Control based in Secaucus, said the protocol is to send mosquitos to the state health department for testing.
“They tell us if any of those mosquitos had West Nile. We do that every week in 15 locations around the county. Wherever we find positive mosquitoes, we’ll go out and spray to try and bring those adult populations down,” said Williams.
He added that so far, it’s been an above normal year in terms of mosquitos. “We’re finding a lot more mosquitos infected with West Nile virus than in previous years, but we’ve been fortunate that the human cases have been kept to a minimum.”
Health officials said that because it is peak WNV season, high mosquito activity is contributing to the spread of the virus. O’Dowd urged residents to protect themselves by using repellent (preferably with DEET as an active ingredient, wearing long-sleeve shirts and pants (rather than shorts), and removing standing water, a breeding ground for mosquitos.
The |New Jersey Department of Environmental Protection (NJDEP) is providing additional funding for the testing of mosquitoes. NJDEP Commissioner Bob Martin said that the resources would help the state and individual counties to more precisely target mosquito control efforts.
According to the health department, New Jersey has confirmed 15 cases of WNV from 12 counties, including: Bergen (1), Burlington (1), Camden (1), Essex (2), Gloucester (1), Hudson (1), Mercer (1), Middlesex (1), Monmouth (1), Ocean (3), Passaic (1) and Salem (1).
In 2010, there were 30 reported cases of WNV in New Jersey, including two deaths. In 2011, there were seven cases with no reported fatalities.
An elderly Burlington County man who tested positive for WNV died last week, according to the health department, after he developed a fever, weakness, and respiratory distress.
Dr. Tina Tan, state epidemiologist, said that the elderly and those with weakened immune systems are particularly at risk of developing serious health complications as a result of being bitten by a mosquito infected by WNV. She urged all residents in the state who are most at risk to protect themselves against mosquito bites.
Dr. George DiFerdinando, Director of The New Jersey Center for Public Health Preparedness at the University of Medicine and Dentistry of New Jersey (UMDNJ) said that while 80 percent of people who get infected with WNV don’t have symptoms and the remaining 20 percent have mild symptoms, he suggests adhering to the recommended precautions such as removing stagnant water and using repellent with DEET. He also advised residents to use caution at dawn and dusk when mosquitos are most active.
Larry Hajna, a spokesman for NJDEP said that one of the challenges is getting people to realize that they should take the normal precautions. “It’s important to deal with it at home, protect yourself by making sure breeding areas are taken care of,” said Hajna.
The NJDEP works with counties to provide them with funding, expertise, and equipment to help them in the surveillance and control of the mosquito population, Hajna said.
Although state health officials are concerned about the rise in number of WNV cases, New Jersey has gotten away pretty easy so far. In contrast, the virus has hit south central and north central states hard, with Texas recording the most cases (888) cases, according to the CDC’s Division of Vector-Borne Diseases. Oklahoma and Mississippi have logged 113 cases each.
Dallas County has implemented an aggressive aerial-spraying initiative that covered 82,400 acres, according to the Dallas County Health & Human Services Department. On Sept. 6, the DCHHS confirmed the 14th WNV-related death.
Why have some areas had such an atypical WNV season? DiFerdinando said that one theory suggests that in places where there have been heavy rains and then a dry cycle, it allows the puddles to stagnate.
“Normally you’d have a rain that would create some puddles and you’d have another rain that would wash those puddles out,” said DiFerdinando. Under those circumstances, he said that there wouldn’t be enough time for the mosquitos to really build up much a mosquito population.
In addition to the mosquito population proliferating, the level of virus in the birds that the mosquitos feed on would have to increase too. “Speculating on whether it’s the amount of virus in the birds, or an unusual cycle for the mosquito, nobody really knows,” DiFerdinando said.
To Spray or Not to Spray?
Spraying to control the mosquito population has been controversial with some environmental groups and healthcare advocates, who point out the dangers that insecticide poses to humans and the environment. However, in New Jersey at least, complaints have been rare.
“The spraying is much more targeted and much more scientific, ” said Hajna. He said that the public understands the necessity for spraying with approved pesticides, which will help control mosquito population and protect the public from disease.
But in Dallas County — where aerial spraying for mosquitos hasn’t been done for more than 40 years — the fine pesticide mist wasn’t welcomed by some residents and health officials, according to media reports.
ABC affiliate WFAA in Dallas reported that Dallas County Health Department Director Zach Thompson was not convinced that chemicals sprayed on highly populated areas was the best solution. Spraying has been limited to specific areas with the highest numbers of cases. Thompson said that he wanted to get more information in order to assess how effective aerial spraying would be.
“You never want to spray if you don’t have to,” said DiFerdinando. He said that in New Jersey it’s reached a good point where spraying is done when needed and where it would have the maximum impact, as opposed to spraying on a routine basis.