By Dr. Teresa Liccardi
West Nile Virus (WNV) has been in the news this past month. There is concern that the incidence of the virus is rising and causing significant illness in some people in certain areas of the United States. Only a very small number of the total national cases of WNV reported to date this year have occurred in New Jersey.
Mosquito control programs, such as the ones in Monmouth County, are important to prevent WNV.
I would like to highlight a few facts and direct you to important websites with information about WNV disease and prevention: the Centers for Disease Control (CDC), and the State of New Jersey Department of Health and the Mosquito Extermination Commission of Monmouth County:
What is West Nile Virus?
West Nile Virus is a mosquito-borne virus that infects humans causing a spectrum of disease from no symptoms in most infected individuals to mild symptoms to more serious presentations. The peak incidence occurs in August and September.
Birds are the reservoir for WNV. There are no documented cases of WNV from handling a dead bird infected with the disease. Infected birds transmit the virus to mosquitoes when the mosquitoes feed on them. The mosquitoes transmit the virus to humans through their bite. Humans and horses may become infected with WNV but are “dead-end hosts” since they do not transmit the disease. Other domestic animals have not been infected with the virus.
When and where was WNV first recognized?
WNV was originally isolated in Uganda in 1937 and since then has been found in Africa, Asia, the Middle East, and more recently in Europe and North America. It was first documented in the U.S. in 1999. It has been isolated in all states except Alaska, Oregon and Hawaii. Mosquito control is key to preventing WNV.
What does New Jersey and Monmouth County do about mosquito control?
The State of New Jersey has a well-developed mosquito control program that conducts routine mosquito surveillance on close to 7,000 sites throughout the state. The Monmouth County Extermination Commission works to prevent mosquito– borne diseases by managing surface water where mosquito breeding occurs and through the use of pesticides that are environmentally approved.
If you are experiencing a mosquito problem, you may request service at 732-542-3630 or co.monmouth.nj.us/page.aspx?ID=177.
Several species of mosquitoes carry the virus. At this time of year, the Asian Tiger mosquito (Aedes albopictus) causes most mosquito problems. It breeds in man-made waters and bites throughout the day not just at dawn and dusk.
The extermination commission has excellent information on mosquitoes and WNV at its website: co.monmouth.nj.us/ page.aspx?ID=2851.
Who is at risk to contract WNV?
Those over the age of 50 years and the immunosuppressed are more susceptible to infection and serious complications.
What are the signs and symptoms of WNV?
Signs and symptoms may occur 2 to 15 days after being bitten by an infected mosquito. Some four out of five individuals infected with the virus do not have any obvious symptoms, and one out of five infected individuals develop mild symptoms including fever, headache, rash and muscle aches. Symptoms may last for several days and occasionally several weeks. However, one in 150 cases of WNV are more serious involving the central and peripheral nervous systems. A complete listing of signs and symptoms may be found at www.state.nj.us/health/ cd/westnile/brochure.pdf
The majority of cases do not require therapy. Treatment for WNV is aimed at symptoms. There are neither vaccines nor specific medications to combat WNV, only supportive care.
Prevention is the best therapy for WNV.
Mosquitoes breed in still water.
Drain standing water including buckets, flowerpots, pools, birdbaths and gutters.
Install and replace screens in windows and doors. When outdoors use mosquito nets for infants and insects repellents for other individuals.
Cover up. Wear long sleeves and long pants if you know you cannot avoid exposure. Since mosquitoes may bite through thin clothing another option is to spray clothing with permethrin.
Not all repellants are equal. Always use a repellant that has an EPA-approved label. Repellants recommended by the CDC are DEET, Picaridin and Oil of Lemon-Eucalyptus (not for use in children under 3 years old). Protection varies depending on the type chosen and the concentration of active ingredients. A 4 percent concentration of DEET affords 90 minutes of protection whereas a 24 percent concentration lasts up to 5 hours. Citronella products, such as Skin So Soft, protect for only a few minutes. “Natural” mosquito repellants have varying degrees of protection and may be skin irritants.
Websites that review mosquito repellants are:
Continuing mosquito vigilance is our best prevention for WNV.
Dr. Teresa Liccardi, who is board certified in internal medicine and nephrology, maintains a clinic for hypertension and chronic kidney disease at the Parker Family Health Center in Red Bank.