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Insects used to be just an annoyance. Now, it seems, they are posing increasing danger to people. For several years West Nile Virus, spread by mosquitoes, has been a threat in the U.S. It can lead to fever or other symptoms and in rare cases, it can be fatal.

This year there's a new mosquito-borne threat. The Centers for Disease Control and Prevention (CDC) reports hundreds of cases of chikungunya, a painful virus spread by mosquitoes.

The first cases showed up in Florida but the virus has since spread to 34 other states. In one of the highest profile cases, Tampa Bay Rays pitcher Joel Peralta revealed last week that he believes he has been infected with the virus. The team has placed him on the disabled list.

Cause for concern

Kansas State University professor Stephen Higgs says outbreaks of chikungunya and its rapid spread is something to worry about. Higgs, one of the world's leading researchers of the virus and director of Kansas State's Biosecurity Research Institute, says because of travel, many more people are now at risk of becoming infected.

"Those travelers have come back from an infected area, most likely the Caribbean, and they've become infectious to mosquitoes because they are carrying chikungunya in their blood," Higgs said. "They have been bitten by mosquitoes in the United States and those mosquitoes have become infected. The mosquitoes go through an intrinsic incubation period and then have enough virus to transmit to new people in the United States."

Part of the problem, says Higgs, is chikungunya is transmitted by two types of mosquitoes, and both are widely found throughout the U.S. While the mosquitoes don't directly transmit the virus to one another, they indirectly spread the virus by biting people.

The way it spreads

"It transmits from person to mosquito to person to mosquito and so forth," Higgs said. "Mosquito biting can be intense and one person can be bitten by dozens of mosquitoes in just a small amount of time. One person could infect lots and lots of mosquitoes and then, unfortunately, the virus can spread from there. Each one of those mosquitoes can infect multiple people."

Symptoms of chikungunya include intense arthritis-like pain in the joints. The pain might go away after a couple of days but it might not. It could last weeks.

Higgs says the best way to avoid the virus is to avoid mosquito bites. Avoid going outside at dusk and dawn when mosquitoes are most active. Eliminate standing water around your house and use insect repellent when you do go outside.

Spider bites

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Mosquitoes aren't the only insects making this summer uncomfortable. Toxicologists at Vanderbilt University say they are seeing more patientsthis summer who have received bites from a brown recluse spider.

Dr. Donna Seger, Medical Director of the Tennessee Poison Center, says these spider bites will usually heal if left alone. But not always, especially if the victim is a child.

Sometimes the spider bites produce something called systemic loxsoscelism, triggering a fever, rash, muscle pain and potential hemolysis, which is the breaking down of red blood cells. That can be life threatening, especially in children, Seger said.

“Our recommendations are that all children under 12 with a brown recluse spider bite should have a urine test for the presence of hemoglobin in blood which indicates hemolysis,” Seger said.

It's unclear why systemic loxsoscelism occurs in some people with a brown recluse spider bite and not in others but when it does, it's life-threatening and requires immediate medical attention. Toxin-induced hemolysis can occur very rapidly, making it more of a threat.

The brown recluse spider is usually between 6–20 mm and light to medium brown, although it can be lighter or darker. It has six eyes instead of eight and can be identified by the violin-shaped marking on its back.  


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