New research from NICHD and NIAAA may explain why the flu virus is more infectious in cold winter temperatures than during warmer weather.

One More Reason to Hate Winter

Yesterday marked the first day of spring, but that doesn’t mean cold temperatures—and with them, the winter flu—may be entirely over. Why is the flu virus more infectious in cold winter weather than in warmer months? New research from NICHD and NIAAA may provide an explanation. Scientists found that at cold temperatures, the virus’s outer covering, or envelope, hardens to a rubbery gel that shields the flu as it passes from person to person. At warmer temperatures, this protective gel melts to a liquid phase that’s not so well-protected from the elements and the virus loses its ability to spread so easily. Scientists said the study results, published online Mar. 2 in Nature Chemical Biology, opens up new avenues of research for reducing the spread of winter flu outbreaks, such as testing detergents and hand-washing protocols that could effectively hinder spread of the virus.

Fighting Asthma at Home

A new study conducted in part by NIEHS has linked increased allergen levels in the home with asthma symptoms in people with allergies. The findings, published online in the March issue of the Journal of Allergy & Clinical Immunology, suggest asthmatics with allergies could alleviate their symptoms by reducing allergen levels in their homes. In a national survey, researchers found that exposure to multiple indoor allergens—like those from dogs, cats, cockroaches and dust mites—was common in U.S. homes, with 52 percent of households having at least six detectable allergens and 46 percent having three or more allergens at increased levels. The study is the first to provide information on total allergen burden in the U.S. and how it relates to asthma. Its results could be helpful to people all over the country who suffer from asthma, a chronic ailment that affects more than 22 million Americans.

New Findings for Bad Odors

More on household irritations: Scientists don’t yet know why certain smells—such as onions, ammonia and paint thinner—can be so overwhelming. But new NIDCD-funded research in mice has uncovered an unexpected role for specific nasal cavity cells in this process. The findings, described in the March issue of the Journal of Neurophysiology, show that a particular cell, abundant near the entry of many animal noses, plays a crucial part in transmitting irritating and potentially dangerous odors. Though the research was conducted with mice, similar solitary chemosensory cells have been found in the nasal cavities, airways and gastrointestinal tracts of many mammals. Scientists think it’s likely they’re also present in humans. Prior to the study, it was thought that irritating odors stimulated the trigeminal nerve; the new research corrects this assumption and expands scientific knowledge of olfaction, which could lead to a better understanding of why some people are especially sensitive to certain smells.

Avoiding Unnecessary Joint Procedures

NIAMS researchers have developed a potential test that could help surgeons confirm or rule out the presence of infection-causing bacteria in prosthetic joints, freeing some patients from an unnecessary procedure. Described in the March issue of the Journal of Bone and Joint Surgery, the diagnostic test could spare a subgroup of people whose prosthetic joints require surgical revision from a time-consuming and costly treatment for infection, while also determining those who truly need the procedure. Each year in the U.S., thousands of prosthetic joints must be removed and replaced due to severe pain and swelling often caused by infection. The standard treatment for suspected infection is to replace the joint prosthesis with a spacer filled with antibiotics, remove the spacer 6 weeks later and then implant the new prosthesis. With the new test, those who don’t have infections could go without this process.—compiled by Sarah Schmelling