(Photo Courtesy of Lowell Sun) “Map of planned route for spray of mosquito pesticides in Lowell, Massachusetts.”
On Aug. 30, the City of Lowell announced that the Massachusetts Department of Public Health had identified mosquitoes that tested positive for West Nile Virus in the area. The samples were collected from mosquitoes found in the Pawtucketville area of Lowell. West Nile Virus is spread primarily through the bite of an infected mosquito.
In order to combat these mosquitoes, the Central Mass Mosquito Control Project conducted preventative pesticide spraying in the Pawtucketville area extending to the Dracut, Tyngsborough and Chelmsford borders on Aug. 31.
West Nile Virus can infect people of all ages, but the demographic at risk is people over the age of 50. Most people infected do not experience any symptoms. However, serious cases can lead to flu-like symptoms and even meningitis.
There are unique public health implications with an insect-borne disease outbreak. However, some of the general public health issues are what UMass Lowell’s Public Health Professor Ann-Marie Matteucci refers to as the “social determinants of health.” She says, “[E]conomic stability is a huge barrier … that can put [people] at risk … How crowded are their living conditions? How well is their transportation working for them? Does their job give them time off if they’re sick? [Do they have a]ccess to healthcare[?] Do they have health insurance[?] … [W]hen we think about that, we see a lot of disparities.”
For city officials who have to rectify the threat, Matteucci says risk-benefit analysis is the key. West Nile Virus is mostly asymptomatic and not especially fatal, so the city has to weigh the risks of spraying pesticides with the risks of potential infections. “Once they get to a certain saturation of the mosquitoes is when they are going to have to start thinking of protecting people … If they were spraying every week, the risk of the pesticides would grow exponentially, but … they’re usually doing it in this window of time where the mosquitoes have really taken hold … We’re just trying to get to the first frost,” says Matteucci. “That’s their risk-benefit analysis. How many people can we potentially save from getting West Nile by doing this one shot, or maybe two shot, sprays? And if there were no mosquitoes with West Nile, they wouldn’t take the risk.”
Another issue about dealing with an insect-borne, or in this case “vector-borne” disease, is that the epidemiological response is completely different than if the disease were in a human population. Matteucci says, “Parallel to COVID[-19], because that’s a thing we all know, that was person-to-person spread … keep people separated, less exposure to each other, that type of thing. When we come to a vector-borne disease, we end up having to deal with either protecting the person or eliminating the vector, the insect. Or we can treat the host population, the birds, which is a little hard.”
The City of Lowell gave tips in a press release on how to avoid getting bit, like applying mosquito repellent, wearing long sleeve clothes and pants and being weary of peak mosquito
hours, which is from dusk till dawn. They also included tips on mosquito proofing, which include “draining or getting rid of items that hold water. Check rain gutters and drains. Empty any unused flowerpots and wading pools and change water in birdbaths frequently.” They also say to replace any screens with holes in them.
For students at UMass Lowell, be weary of when and where outdoor clubs or sports meet. If possible, consider meeting indoors during those peak mosquito hours. If not, wear long sleeves or bug spray before going outside.