Tick Bite? What to Do

 

Smell Evolution Humans' sense of smell, and how we use smell to interact with the world, has been changing for the past few millennia. Plus, changes to the way we live and our environment have further altered it. In a recent study, scientists analyzed genomes from 50 Indigenous hunter-gatherer people from the Malay Peninsula and compared them with two other Indigenous groups that conduct farming and agriculture. The results suggest that the Malay Peninsula hunter-gatherers have preserved a more complete set of smell-receptor genes than the other groups studied. Why this is interesting: In most populations around the world, many smell receptor genes have accumulated mutations over time that have left about 60 percent of them nonfunctional. But the hunter-gatherers showed significantly fewer mutations. The intact gene variants they carry are linked to sensing earthy, floral and fruity smells—cues often tied to food and other vital resources. According to the researchers, smell has an enduring importance in the Malay Peninsula hunter-gatherers’ culture, and their language has a strikingly rich vocabulary for odors. What the experts say: Hunter-gatherer populations, long underrepresented in genomic research, have allowed the survival of genetic signatures tied to ancient history and have also led to new adaptations. “Such living populations can be invaluable for understanding the deep history of human genetic diversity,” says Lian Deng, a geneticist at the School of Life Sciences at China’s Fudan University. —Emma Gometz, Newsletter Editor

Tick Plight Summer is winding down for many people, but we’re still in tick season. What to do if you (or a loved one) discovers a tick attached to your body? Here’s a step-by-step guide. In the meantime, keep ticks off by following tips found here. Tick bite? Here's what to do:  Remove the tick as soon as you discover it. Don’t wait to go to a health care provider, the CDC advises. The longer a tick is attached, the more time it has to transmit bacteria and other pathogens that cause disease. Infected ticks generally need to be attached for more than 24 hours to transmit Lyme disease, but they may transmit Powassan virus in as little as 15 minutes. The sooner you get the tick off your body, the better. Use tweezers to pluck the bug straight off your skin (don’t crush it) and put it in a clear, sealable plastic bag for identification and possible lab analysis. Identify the tick: Tick species differ in size, colors and markings, but individuals of the same species can look different depending on what their life stage and sex are and how engorged they are from a blood meal (ugh). Click through to see our primer on identifying ticks and their anatomy (and your doctor might be able to help too).  Knowing which ticks are most prevalent in your area can help you decide whether you should get your tick tested by a lab for diseases or should start treatment right away. For example, if you were bitten by a black-legged tick in an area where Lyme is common and your tick was attached for 36 hours or more, your doctor may recommend a single prophylactic dose of the antibiotic doxycycline to kill bacteria before they multiply.​ These maps show the approximate distributions of four tick species that transmit disease to humans in the U.S.

Jen Christiansen (maps), Diogo Guerra (tick illustrations); Sources: Centers for Disease Control and Prevention; Pacific Southwest Regional Center of Excellence in Vector-Borne Diseases (references)

Test your tick: Even if you do take a prophylactic dose of antibiotics, a lab analysis of your tick can yield information about other pathogens that the tick might have passed along when it bit you, such as the microscopic Babesia parasites that cause the blood disease babesiosis, which can co-occur with Lyme disease.  Watch for symptoms: The standard advice following a tick bite is to wait and watch for fever, rash or flulike illness over the next 30 days and see a doctor right away if any symptoms appear. Many tick-borne diseases have similar symptoms, particularly in the early stages of infection. Blood tests can differentiate but may take a while. Knowing which species of tick bit you and where you might have picked it up can help your doctor make a timely diagnosis. What the experts say: “If you live in an area with tick-borne diseases, and most people in the United States do, you should educate yourself about the times of year and the kinds of habitats that put you at risk,” says Ecologist Felicia Keesing. https://www.scientificamerican.com/newsletters/?utm_source=Klaviyo&utm_medium=email&utm_campaign=TIS_090426&utm_term=Today%20in%20Science%20logo&_kx=hwP4LL9skaZaSCO2L5-3cSl5nTGhgcCaFVqWLRB05eE.WEer5A