Rutgers Researchers Help State Take Aim at West Nile Virus

The current outbreak of West Nile virus is proving to be the worst since the disease was first recorded in New York 13 years ago, and it shows no indication of slowing down. As of the beginning of this month, the federal Centers for Disease Control and Prevention (CDC) had received more than 1,900 reports of West Nile virus cases across the country, and 87 deaths. While certainly not the hardest hit – that would be Texas, the latest figures indicate -- New Jersey is among the growing number of states where the mosquito-transmitted illness has surfaced. Eight cases have been recorded in New Jersey as of September 4, according to the New Jersey Department of Health.

The Rutgers Center for Vector Biology has been involved in research, teaching and outreach about mosquitoes since the turn of the last century. Affiliated with Rutgers’ New Jersey Agricultural Experiment Station, the center focuses on insects that affect both public health and the state’s economy. Rutgers Today spoke with center Director Randy Gaugler; Dina Fonseca, associate professor of entomology; Scott Crans, senior program coordinator; and Lisa Reed, field researcher, for an overview of the impact of the West Nile virus, particularly as it affects Garden State residents.

Center for Vector Biology: First, there is never a need to panic, as this disease is very manageable given the proper tools, information and available mosquito control. Some years are worse than others, which might be explained by conditions such as drought (as experienced by the Midwest this year) that brings mosquito vectors (carriers) and bird carriers of the disease together, and/or changes in the virus itself.

Rutgers Today: Can you explain the trajectory the virus takes as it travels from infected bird to mosquito to human?

Center: A female mosquito may bite an affected bird in order to get a blood meal. The protein in the blood is used to develop eggs. If the bird was infected, the virus will end up in the mosquito’s gut. The virus travels from the gut to the salivary glands of the mosquito. When a second blood meal is taken, the mosquito will inject some saliva when “biting,” because the anticoagulants in the saliva make it easier to suck blood. The injection of saliva delivers the virus to whoever is supplying the blood, be it another bird, a horse or a human.

Rutgers Today: What are the symptoms, and how long after exposure are they likely to appear? Once a person has shown the first symptoms, how long does it take for the virus to run its course, and what long-term effects might it leave behind?

Center: It’s estimated that about 80 percent of all people exposed to West Nile virus will not show any symptoms. Most of the rest develop what is termed West Nile fever, which is much like a summer cold: fever, headache, fatigue, and sometimes a rash, swollen glands and eye pain. It may be severe enough to send you to a doctor. About one in 150 will develop what is called West Nile neuroinvasive disease, which produces central nervous system symptoms such as paralysis and changes in mental status. The incubation period is about two to 14 days. For more severe forms of the disease, the amount of time it takes to run its course is variable, and can leave long-term effects. The mortality rate for those with the most severe form is between 3 and 15 percent.

Rutgers Today: In New Jersey, all 21 counties have mosquito-control programs of some sort, and your experts are playing a large role. Please tell us where you’re focusing your efforts

Center:  At Rutgers, research is being done on developing an effective strategy for controlling one of the competent vectors of West Nile virus, the Asian tiger mosquito, or Aedes albopictus. Other research areas include examining the efficacy of various new pesticides and pesticide resistance, as well as basic research on the biology and ecology of the main mosquito vectors. We offer classes to mosquito-control personnel on how to identify mosquitoes by species, habitat and biology, aiding in their integrated pest management strategies, and we report on arbovirus levels and mosquito population trends during the mosquito season.

Rutgers Today: What steps can New Jersey residents take to minimize the risk of contracting the disease?

Center: There are several things people can do to reduce the risk of getting bitten. These are called the five Ds: Use Deet (read the instructions and see http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm); Dress with long sleeves and pants; avoid Dusk and Dawn, when mosquitoes are most active; and Drain water from around your house, including spots such as pots, gutters, bird baths and other containers.

Rutgers Today: What are the long-term public health implications of West Nile virus, and what measures is the federal government taking to contain future risks?

Center: West Nile virus is an excellent example of the global reach any organism can have on this planet. Because of the ease of travel and the growth of human population in new habitats, we can expect new diseases to make their presence known by emerging in potentially deadly ways. West Nile Virus should be interpreted as a wake-up call for the need to step up coordinated efforts to reduce introduction, establishment and expansion of new invasive vectors and diseases.