Mosquito magnets

Researchers at Johns Hopkins University recently developed a smell test to show how mosquitoes that transmit malaria are attracted to humans. Their test marks the first large-scale experiment examining mosquitoes’ preferences for human scent.

The researchers performed the test in Zambia, where malaria is the top-ranking cause of hospitalization. The mosquitoes were enclosed in a screened, outdoor “flight cage.” To target activity of the mosquito Anopheles gambiae, a nocturnal hunter, the scents of humans sleeping in nearby tents were piped into the cage overnight.

Based on the mosquitoes’ landing behavior, the team found that the most attractive scent profile consisted predominantly of airborne carboxylic acids, including butyric acid, present in “stinky cheeses” such as Limburger. Carboxylic acids are produced by ­bacteria living on human skin.

The least attractive scent to mosquitoes was rich in a plant chemical called eucalyptol. Researcher Conor McMeniman explained in a press release that the scent profiles could be used to develop chemical repellents to ward off malaria-carrying mosquitoes.

The study was published May 19 in Current Biology.

New weapon in overdose fight

A new nasal spray for countering opioid overdoses received U.S. Food and Drug Administration approval on May 22. Branded as Opvee, the spray contains nalmefene, an opioid receptor antagonist. Nalmefene is similar to naloxone, a commonly used “rescue” drug for opioid overdoses sold under the brand name Narcan. Both drugs reverse the effects of opioids on the brain, restoring depressed breathing and blood pressure rates to normal levels. Opvee will be available for adults and pediatric patients ages 12 years and up.

Opvee was developed as a longer-lasting ­alternative to Narcan. Fentanyl, the leading cause of overdose death in the United States, stays in the body longer than other opioids and can take several doses of Narcan to treat. But some experts claim Opvee comes with a longer withdrawal period—several hours versus 40 minutes for Narcan—potentially requiring additional medical treatment. —H.F.

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Skin-saving medicine

The FDA on May 19 approved the first drug for a rare skin disease called dystrophic epidermolysis bullosa (DEB). Patients with DEB, a genetic disorder caused by mutations in the COL7A1 gene, have very fragile skin prone to blisters and chronic wounds. The new drug is a gel called Vyjuvek: When rubbed onto the skin, it accelerates wound and blister healing by delivering normal copies of the COL7A1 gene into patients’ cells. —H.F.