“Bzzzzz.” Cold weather has quieted that sound for many Americans, but mosquitoes are still creating a buzz. According to BMJ, mosquitoes native to the United States may be responsible for two cases of Plasmodium vivax malaria in the Washington, D.C., area last summer. Some infected mosquitoes that were found had escaped from Dulles international airport, but health officials suspect that the indigenous pests transmitted the illness. Malaria, which rarely occurs in the United States, is almost always acquired overseas.

Herbs 101. Physicians Financial News reports that doctors, pharmacists, and dietitians may need to brush up on their knowledge of herbal supplements. A study published in Academic Medicine described a test of more than 500 health care professionals. At the beginning of the study, participants answered only about 67 percent of the questions about herbal medicines. Their scores improved, however, after they completed 10 weeks of e-mail instruction on herbs and dietary supplements.

This tomato juice won't hurt a bit. According to Time, a biologist from Arizona State University has developed a “tomato vaccine” that may one day help lower the incidence of diarrheal illness. The vaccine, made from the freeze-dried juice of tomatoes that carry a gene from a strain of Escherichia coli bacterium, was included on the magazine's list of best inventions for 2002. It has not yet been tested in humans or animals. Numerous other researchers are also studying plant-derived vaccines, which could be relatively inexpensive and easy to distribute in developing countries.

“We?re having our own grandkids…” said a woman who had twin boys at the age of 55. Women in their 50s are able to conceive and carry babies to term with donated eggs, according to a study published in JAMA. Pregnancy, childbirth, and multiple-birth rates in this age group were similar to those in younger recipients of oocyte donation. Of the 77 postmenopausal women who participated in the study, 42 (54.5 percent) had babies. However, women older than 50 years are more likely to develop preeclampsia and gestational diabetes during the pregnancy and more likely to have cesarean deliveries.

Like dust bunnies under a bed, accumulating evidence shows that bad hygiene is actually good for your health, or so says an article published in the Washington Post. Researchers who support these findings propose that either early exposure to allergens changes the way the human immune system responds to them or that developed nations are so clean we are hampering the development of our own immune systems. Despite these recent reports, researchers don't recommend day care as a form of disease prevention or farming as a health insurance plan.

“As seen on TV…” If you're keeping up with the ailments of the characters on soap operas, maybe you shouldn't be. According to the BBC News, a recent survey shows that more Britons are coming down with “telly belly,” a condition characterized by symptoms suspiciously similar to those recently featured in television news reports or soap opera story lines. Of more than 200 family doctors surveyed in Great Britain, nine out of 10 said they thought media coverage affected their patients. They also said their patients were more likely to self-diagnose these days than they were 10 years ago.