West Nile virus scant in mosquitoes in Allegheny County this summer
This summer, a single mosquito in Allegheny County has tested positive for West Nile virus — a contrast with last year, when mosquitoes tested positive in May.
“We don't really know why,” said Dave Zazac, a spokesman for the county Health Department.
Mosquito samples tested positive for the virus in Beaver and Erie counties, according to the state Department of Health. Fifteen other counties, mostly in Southeastern Pennsylvania, reported positive samples. Almost all of the 28 confirmed cases involved mosquitoes, the Department of Health website shows. One avian case was reported in Erie County.
No human cases of the virus have been diagnosed. Allegheny County had two nonfatal cases last year.
“There is a concern about people getting infected. Last year was one of the worst years for West Nile,” said Kait Gillis, a spokeswoman for the state Health Department.
In Pennsylvania, four of 60 people who contracted the virus died in 2012, records show. It was the state's second-worst year for West Nile. In 2003, there were 237 cases and nine deaths.
Health officials reported 5,674 cases of the disease nationwide last year and 286 deaths — the highest number ever. As of July 16, the Centers for Disease Control and Prevention reported 23 cases of West Nile nationwide, including three deaths.
Some experts believe last year's mild winter, the wet and warm spring and then a drought caused mosquitoes to get the virus from feeding on infected birds and sharing water with them.
Shannon LaDeau, an ecologist and West Nile expert at Cary Institute of Ecosystem Studies in Millbrook, N.Y., would not predict how this summer's rates of West Nile might compare with other years.
“It is a little bit of a better year. Everything got pushed back. It may be late enough that we will not see the same spillover of the virus into humans that there was last year,” she said.
Before last year's outbreak, incidence of West Nile was relatively low for nearly a decade. Heat waves and drought could accelerate outbreaks, LaDeau said.
Rick Wills is a Trib Total Media staff writer. He can be reached at 412-320-7944 or firstname.lastname@example.org.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.