A shift in the feeding behavior of Culex mosquitoes (their larvae amass in standing water, as seen above) helps explain the rising incidence of West Nile virus in North America. (Image: James Gathany, CDC)Since its introduction to the United States in 1999, West Nile virus has become the major vector-borne disease in the U.S., with 770 reported deaths, 20,000 reported illnesses, and perhaps around a million people infected. The virus is transmitted by Culex mosquitoes (the "vector") and cycles between birds that the mosquitoes feed on. Humans can also be infected with the virus when bitten by these mosquitoes.

In the first study of native African honeybees and honey-making stingless bees in the same habitat, humans and chimpanzees are the primary bee nest predators. Robert Kajobe of the Dutch Tropical Bee Research Unit and David Roubik from the Smithsonian Tropical Research Institute report this finding in the March, 2006 issue of Biotropica.

Yale biomedical engineers have created an implantable system that can form and stabilize a functional network of fine blood vessels critical for supporting tissues in the body, according to a report in the Proceedings of the National Academy of Sciences.

The MRSA 'superbug' evades many of the measures introduced to combat its spread by infecting a common single-celled organism found almost everywhere in hospital wards, according to new research published in the journal Environmental Microbiology.

In addition to triggering a depression-like social withdrawal syndrome, repeated defeat by dominant animals leaves a mouse with an enduring "molecular scar" in its brain that could help to explain why depression is so difficult to cure, suggest researchers funded by the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH).

Therapy that involved bone marrow stem cells did not improve cardiac function in patients following a heart attack, according to a study in the March 1 issue of JAMA.

Predators are, ironically, the key to keeping the world green, because they keep the numbers of plant-eating herbivores under control, reports a research team lead by John Terborgh, a professor of environmental science at Duke University's Nicholas School of the Environment and Earth Sciences.

Combining aggressive HIV therapy and chemotherapy significantly improves the survival rates of HIV-positive men and women treated for lymphoma, according to a new study.

New research shows that highly active antiretroviral therapy (HAART) is very cost-effective, despite the high price tag. However, the study also shows that reimbursement to physicians treating patients with HIV is critically low, threatening patients' access to care. The study findings are reported in the April 1 issue of Clinical Infectious Diseases, now available online.