Stories tagged mosquito

Mosquito: Researchers have tracked several traits that make people be more susceptible to mosquito bites. How do you rate?
Mosquito: Researchers have tracked several traits that make people be more susceptible to mosquito bites. How do you rate?Courtesy JJ Harrison
With all the rain we've had this summer, the conditions are prime for creating large mosquito populations. And researchers have now figured out certain factors – like blood type – that can make people be more tasty targets for the little buzzers. Question, do you think mosquitoes prefer to strike beer drinkers? Click here to find the answer to that, and other factors that can impact your appeal to mosquitoes.

Jan
18
2008

Aedes aegypti mosquito
Aedes aegypti mosquitoCourtesy Photo courtesy Centers for Disease Control and Prevention
A re-emerging threat
Dengue fever is making a come back in South America and some fear it could become a problem again in the US as well. The year 2007 was an epidemic record-breaking year there was an 11% increase in reported dengue cases when comparing 2006 to 2007. Some even fear it could be spreading to the US. There was a recent article in the Los Angeles Times about it reappearing in the US.
What is dengue fever?
Dengue is a viral infection spread by the predominantly urban species Aedes aegypti mosquitoes. In recent years dengue has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.
Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death. Dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena--often with enlargement of the liver--and in severe cases, circulatory failure.
Why is dengue making a come back?
Potential reasons include climate influences like global warming, El Niño / Southern Oscillation and La Niña, both of which influence the intensity and duration of the rainy seasons and hurricanes or induce intense droughts and damage to biodiversity. Another potential cause is population growth and increased opportunities for mosquitoes to breed.
On the other hand, micro factors exist that are dependent on the agent (virus) and the vector (mosquito)—which at times exhibits a growing resistance to insecticides—and the host, all of which closely influence the manifestation of the disease and its more serious forms.

Mar
20
2007

A new weapon against mosquito-borne malaria may be... the mosquitoes themselves: Photo USDA
A new weapon against mosquito-borne malaria may be... the mosquitoes themselves: Photo USDA

Researchers as Johns Hopkins University have genetically engineered a mosquito that is immune to malaria found in mice. The resistant mosquitoes caught the disease less often than wild bugs, and within a few generations widely outnumbered the non-resistant group.

Scientists warn that they are still a long way from developing a mosquito that is resistant to human malaria, let alone testing it or releasing it in the wild. But these early results indicate this could be a promising means of eradicating this deadly disease.

To learn more about malaria, visit the Science Museum’s on-line exhibit.

Honeybee: Courtesy Wikipedia
Honeybee: Courtesy Wikipedia
Scientists have unraveled the honeybee’s genetic code. Information was ascertained pertaining to the honeybee’s complex social behavior patterns, keen sense of smell and African origin. This is the third insect to have its genome mapped. Other insects which have had their genome mapped include the fruit fly and mosquito.

Jul
27
2006

A Big Deal? :: While we're moving into prime time for moquitoes carrying West Nile disease, is it really that big of a deal? Last year just three deaths in Minnesota were attributed to West Nile.  (Photo courtesy of the U.S. Department of Agriculture)
A Big Deal? :: While we're moving into prime time for moquitoes carrying West Nile disease, is it really that big of a deal? Last year just three deaths in Minnesota were attributed to West Nile. (Photo courtesy of the U.S. Department of Agriculture)

Minnesota has recorded its first fatality from the West Nile virus. A Minneapolis woman in her 70s died in early July from the disease, which is primarily carried by mosquitoes.

As the Science Buzz’s resident expert on mosquitoes (see the recent posting “That Really Bites”), I’m here to open a discussion about whether or not West Nile is something to be feared. For several summers now we’ve been receiving media reports about West Nile and its deadly consequences.

But last year, there were only 45 recorded cases of West Nile disease in Minnesota and just three reported deaths. Is this something we should really be freaking out about? What do you think? Personally, I'm more afraid of surviving my drive home than being bitten by a mosquito.

According to information from the Minnesota Department of Health, we’re now moving into the highest risk time period for West Nile – mid-July through September. That’s when the mosquitoes most likely to carry West Nile will be hatched and feeding. But this year’s dry weather conditions have made for less standing water, the prime hatching grounds for mosquitoes.

The health department does share these tips to help lower your West Nile risk:

  • While outside among mosquitoes, use a good mosquito repellent, such as those containing no more than 30 percent of the active ingredient DEET. Products containing the active ingredient picaridin are also now commercially available.
  • Minimize outdoor activities at dusk or dawn, when mosquitoes are most actively feeding.
  • Wear long-sleeve shirts and long pants if you have to spend time in an area where mosquitoes are biting.
  • Eliminate mosquito breeding sites on and around your property - including items such as old tires, buckets, clogged rain gutters, cans, other containers, and anything else that can hold a small amount of water. Change the water in birdbaths and horse troughs at least weekly.

The state health department also is gearing down its alarms about West Nile. It added that most people bitten by an infected mosquito will experience a less severe form of the disease or no symptoms at all. Fewer than one out of every 150 people who become infected will become severely ill with encephalitis, an inflammation of the brain. The elderly are at greatest risk of developing encephalitis from a West Nile infection. The fatality rate for those who develop encephalitis is around 10 percent.

Symptoms of the illness usually show up two to 15 days after being bitten. They can include headache, high fever, muscle weakness, stiff neck, disorientation, tremors, convulsions, paralysis and coma. People who suspect that they may have West Nile should see a physician.

For more information on West Nile and other forms of mosquito-related encephalitis visit the Health Department website or call 651-201-5414 in the Twin Cities area, or 1-877-676-5414 in greater Minnesota, between 8 a.m. and 4:30 p.m., Monday through Friday.