Mosquito surveillance starts with West Nile, Zika concerns
Penn State Extension has started its annual mosquito surveillance as concerns about Zika transmission continue to grow.
"York County is No. 1 in the state for West Nile," said Thomas Smith, West Nile virus program administrator for the Penn State Extension of York County. "We can't get people to clean up. A lot of the mosquitoes would go away if people didn't leave standing water in their yards."
However, local experts say those concerns shouldn't be as high as concerns about West Nile infections.
Smith said 31 species of mosquitoes can be found in York County, depending on the amount of rain and the transfer of mosquitoes to the area from other sources. Thousands of mosquitoes can come from just 10 mosquitoes who make it to adulthood.
West Nile: In 2015, York County led in the number of mosquitoes collected for West Nile testing, according to the Pennsylvania West Nile Program. About 30 percent of the mosquitoes collected were carrying West Nile virus.
According to the Centers for Disease Control and Prevention (CDC), West Nile was first detected in the United States in 1999. It has since spread across the U.S. The virus can cause brain inflammation or meningitis, inflammation of the lining of the brain and spinal cord.
West Nile is most commonly found in birds, Smith said. Mosquitoes transmit the virus to humans after feeding on the birds and can spread it to other animals as well.
Zika: Recent news has focused on Zika, a virus that originated in the Zika Forest in Uganda. Health care providers are trying to educate people, especially pregnant women and women in childbearing years, on the infection that can cause birth defects such as microcephaly — abnormally small heads with incomplete brain development — and possibly the autoimmune disease Guillain-Barré syndrome, which causes paralysis.
Zika is usually found in the Aedes aegypti mosquito, which stays in southerly regions.
Infectious disease doctors weren't too worried about the reach of Zika to more northern states in the U.S. However, the Pan American Health Organization recently reported another species of mosquito can carry the virus.
Asian tiger mosquitoes, or Aedes albopictus, have a farther reach north than the Aedes aegypti. This mosquito can be found as far north as New England and the lower Great Lakes region.
Concerns: Dr. James Hole, a perinatologist with WellSpan Maternal-Fetal Medicine, said West Nile should be more of a concern for people than Zika.
"The bottom line is that, especially for this year, the likelihood of endemic Zika in our area of the U.S. is very low," Hole said. "For all 50 states, there have been no locally acquired cases. There have been travel-associated cases of Zika, but for Pennsylvania itself, for summertime, we're right on the edge of the aegypti species line."
Hole said at this point, it is much more likely that someone will contract West Nile from a mosquito rather than Zika. He added people should be concerned about dengue and Chikungunya, both viruses that can be spread by aegypti and albopictus mosquitoes and have far worse symptoms than Zika.
"We see those just as much as Zika," Hole said. "(Dengue and chikungunya) don't have any of threat of fetal issues either. Your likelihood of contracting Zika is extremely low unless you're traveling to an area that is experiencing endemic spreading."
Education and reporting: Both Hole and Smith said educating the public on these viral threats and how to protect themselves is important.
Smith said using a repellent spray while outside at dawn and dusk is a great way to keep the mosquitoes off. He also said using an electric fan can help keep mosquitoes at bay.
"Mosquitoes don't like wind," Smith said. "They can't fly then."
Hole said he's working with his patients to alleviate any anxiety they may have during their pregnancies. He said if a woman is thinking of getting pregnant, she should make sure not to travel to endemic areas, such as Puerto Rico and Central American countries.
Doctors and epidemiologists are still working on answering questions people have about Zika and its link to birth defects and other issues.
"The answers to most of the questions right now is that we aren't quite sure," Hole said. "We know women can get infected through mosquitoes and that a mother can infect their child while pregnant, but we're still not sure if it always affects the baby."
To stay up to date on Zika and its spread, visit the CDC website.
— Reach Katherine Ranzenberger at firstname.lastname@example.org or on Twitter at @YDKatherine