Stories tagged vector borne


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.


According to the Minnesota Department of Health, there were 1,023 recorded cases of Lyme Disease in Minnesota in 2004. This number is more than double the 473 cases reported in 2003. The increase could be the result of mild winters that have allowed the deer and field mice that the deer ticks feed on to survive the winters in greater numbers.

Lyme disease is a potentially serious bacterial infection that can result in flu like symptoms and if untreated can lead to arthritis, nervous system problems and persistent fatigue. Antibiotic treatment is effective, especially if treatment is begun during the early stages.

The disease is spread when an infected deer tick attaches itself to a person. Not all deer ticks are infected with the bacteria, so not all deer ticks will transmit the disease. In order for the infection to be transferred from an infected deer tick to a person, the tick needs to be attached for at least 24 hours.

To protect yourself from contracting Lyme disease you should avoid tick habitats, if possible. If avoiding tick habitats is not possible, use a tick repellent containing DEET and wear light-colored clothes so you can more easily spot a deer tick on you. Check for ticks after being in their habitats and if you find a tick on you, remove it as soon as possible.