In a small room on the west edge of Williston, a crew of summer interns and workers huddle intently over plastic foam plates piled high with something most would prefer not be set before them — mosquitoes, by the 4- and 6-ounce piles.
The mosquitoes, of course, are not for lunch. They are being carefully sorted to find a species of particular concern, the culex tarsalis. It is the only mosquito in the region that can both carry and transmit West Nile virus to a human host, and that makes it a public health enemy, over and above the general nuisance that mosquitoes present.
The interns are part of the early warning system for West Nile in Williston, working daily to count the numbers of c. tarsalis in area traps, and then test them for the presence of the West Nile virus.
High numbers of c. tarsalis can trigger spraying campaigns, as can the presence of West Nile in these specimens.
Lately, the interns have been finding ultra-high levels of c. tarsalis in their traps. In fact, it is the most Williston Vector Control’s Director Fran Bosch remembers seeing in 10 years. Four traps in the city had more than 10 c. tarsalis in them, and one trap by itself had 300-plus of the species.
Extended flooding and higher than average temperatures are driving the record numbers, Bosch said.
On Thursday, the first specimens tested positive for West Nile virus, and specimens taken from the riverside south of Williston have continued to test positive for it Friday and Monday. While planes could not fly Thursday night, spray was put down both Friday and Monday.
Most people don’t suffer serious symptoms from contracting West Nile virus, but others are not so lucky. Last year in the state, 85 were sickened enough to be tested for the virus, and 28 were hospitalized with serious complications. Two of these died.
No one knows for certain what factors play into a more serious illness from West Nile. But enough suffer that appropriate steps to protect human health are taken. Without interns and summer workers, however, it would be difficult for Williston Vector Control to find appropriate employees for the work which helps determine when the West Nile campaign must be most in earnest.
Not only is this job seasonal, but it requires a certain level of training. The Bakken’s perpetual labor crunch makes hiring appropriately trained individuals difficult, but the internships provide Williston Vector Control with students who have appropriate training or education, while giving the students experience in their chosen career.
Gonzaga University annually sends interns to Williston Vector Control’s program, but this year so has Kent State University in Ohio.
Cameron Marsh is one of two Gonzaga interns working with Williston Vector Control. He is a sophomore majoring in biology with a minor in international relations and leadership.
“I’m hoping to go into the Peace Corps after graduation and then possibly medical school for a master’s in public health,” he said.
He’s happy with his internship, which he said has been a career builder.
“It’s interaction with public health, biology and the environment,” he said.
Sarah Bempah is the Kent State intern, originally from Ghana. She has been in the U.S. since 2015. She’s just finished a bachelor’s and master’s in public health, and will be working on a Ph.D. project using GIS to map public health concerns.
She, too, is interested in global health issues and hoping to work for an international organization devoted to helping impoverished countries mitigate health concerns.
“It has been interesting,” she said. “I have seen more mosquitoes here than I’ve ever seen in my life.”
In all, there are 12 summer workers, including the three college interns, working for Williston Vector Control this summer to keep tabs on the c. tarsalis population in Williston and surrounding areas.
Right now, what the interns are seeing is that c. tarsalis is about 70 percent of the mosquito population in the area. Thus, if you see a mosquito, there is a better than 50-50 chance it’s the West Nile species. Public health officials have recommended using insect repellant and wearing long sleeves if you will be outdoors. While the warning usually identifies dawn and dusk as the most active hours, mosquitoes can be active at other times of the day as well, particularly when near water.
Traps by the riverside south of Williston are dominated by c. tarsalis right now, and that is also where the West Nile virus was confirmed. Anyone in that general area should take extra precautions to prevent mosquito bites.
A c. tarsalis mosquito generally needs from one to three blood meals to complete the development of her eggs, giving the female three chances to either contract or pass along West Nile virus to people, birds or other mammals. Male mosquitoes do not suck blood.
The mosquito population in the area picks up West Nile from migratory species such as waterfowl, many of which are southwest of Williston near the Big Timber area and in the Lewis and Clark Wildlife Management area.
Only larviciding is permitted in the wildlife management area, since it is federally managed. Adult mosquitoes coming out of the wildlife management area can and often do drift north in great numbers, which tends to increase the amount of adulticide that needs to be sprayed in Williston and surrounding areas.
Traps in the Skunk Hollow area, which are adjacent to the wildlife management area, have been carrying between 4 and 6 ounces of mosquitoes each, an indication of the epic proportion of this year’s mosquito problems in the areas that lie on Williston’s outskirts.