West Nile Virus Threat Looms in Cook County

Officials at the Cook County Department of Public Health say weather over the last week has provided an ideal breeding ground for West Niles Virus-carrying mosquitos, and residents need to take precautions right now.                 

        

Mosquito pools in nine suburban Cook County communities, including Wheeling, have already tested positive for West Nile Virus-carrying Culex mosquitos. Photo credit: Cook County Department of Public Health.              

 

The threat of contracting West Nile Virus is likely imminent, as mosquito pools in nine suburban Cook County communities, including Wheeling, have already tested positive for the disease.   

Cook County Department of Public Health (CCDPH) officials say now is the time to take simple, but effective precautions to help protect you and your family against contracting West Nile Virus from the Culex mosquito, which carries the disease.

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After recent heavy rains, Amy Poore, director of public relations for the Cook County Department of Public Health, says residents should empty any items in and around their homes that have collected water, such as old tires, bird baths, baby pools, buckets and other objects.

Poore said these areas provide the most ideal breeding ground for Culex mosquito.
“This is really the time to pay attention, you can reduce your risk by making sure there are no tears in your screens at home, wear repellant with DEET, oil of lemon Eucalyptus or Picaridin between dusk and dawn and keep your gutters clean,” Poore said.

Residents also are advised to keep yard grass cut short, because tall grass also is an ideal area where the Culex mosquito can breed.

Poore said surveillance to identify Culex mosquitos already has been conducted by the CCDPH, in addition to Mosquito Abatement districts in Cook County. Mosquito traps are set in suburban Cook County communities to determine if the insects are carrying West Nile Virus.
Though there are no reported human cases yet in Cook County, Poore said more than 2,000 mosquito pools already have tested positive in Wheeling, Evanston, Skokie, Alsip, Evergreen Park, Forest Park, Hillside, Hodgkins and Oak Park.

Because of the lapse time between trapping the mosquitos and determining if they are indeed carrying West Nile, Poore said it is possible that mosquitos carrying the virus are spreading to neighboring communities - so taking precautions now is even more important.

Cook County residents can also help to curb the spread of the Culex mosquito by reporting any dead birds they observe. Poore said many times, mosquitos feed on dead birds that are carrying West Nile.
If you observe a dead bird near you, you are urged to report it to the CCDPH online or call 708-633-8025 immediately.

For more information on West Nile Virus and how to protect you and your family, visit the Cook County Department of Public Health website.

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Smelly feet drive malaria-infected mosquitoes wild

Mosquitoes infected with the malaria parasite are more attracted to the smell of sweat than uninfected insects, a new study finds.             

           

Photo: Zhiltsov Alexandr/Shutterstock

 

Parasites can be cunning little organisms; not only do they live on and feed from their hosts, but they can manipulate the behavior of the hosts to further their cause. For example, scientists have previously confirmed that mosquitoes infected with the clever malaria parasite want longer and more frequent blood meals than non-infected mosquitoes, better facilitating parasite transmission from mosquito to human.

 

And now a team led by Renate Smallegange of Wageningen University and Research Center in the Netherlands has found another way the malaria parasite bewitches its host; it lures them to the smell of human sweat.

 

Describing the interaction of mosquito Anopheles gambiae sensu stricto with the malaria parasite, Plasmodium falciparum as “one of the most important interactions in the context of humanity, with malaria causing over 200 million human cases and over 770 thousand deaths each year,” the researchers set out to demonstrate how the parasite alters mosquito behavior in response to olfactory stimuli.

 

And what better place to start than with a stinky sock?

 

A volunteer wore a nylon stocking for 20 hours; the fragrant sock was then introduced into a cage with both infected and non-infected mosquitoes. The malaria-infected mosquitoes performed significantly more landings and probing attempts in response to human odor than the uninfected mosquitoes — three times as frequently in fact. This “suggests that malaria-infectious females are more attracted to human odors than uninfected mosquitoes,” write the authors of the report that was published in PLOS ONE.

 

It remains unclear how the parasite manipulates mosquitoes’ sense of smell, or which part of human odor is most seductive to the mosquitoes. Uncovering that information could help researchers develop traps to catch infected mosquitoes, the scientists say.

 

But nonetheless, the study sheds important light on how malaria infects so many people.

 

“The results of our study provide vital information that could be used to provide better predictions of how malaria is transmitted from human being to human being by An. gambiae s.s. females,” the authors conclude.

 

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