12 July 2018
THURSDAY, July 12, 2018 (HealthDay News) — Think you live in a place that’s free from disease-carrying ticks? Don’t be so sure. Citizen scientists found ticks capable of transmitting Lyme disease and other tick-borne illnesses in dozens of places across the United States where the pests had never previously been recorded, a new study reports. All told, disease-carrying ticks were detected in 83 counties where they’d never been found before across 24 states. The numbers reflect a rise in tick populations across the country, said study author Nate Nieto. He’s an associate professor with Northern Arizona University’s department of biological sciences. “People should be aware of ticks and tick-borne disease, even when they may think there’s not a recorded incidence of a tick in a county,” Nieto said. “These things, they’re not obeying borders. They’re going by biology. If they get moved there by a deer or bird or people or pets, they’re going to establish themselves and start growing.” The massive nationwide study also provides evidence that ticks are born carrying infectious diseases, rather than picking germs up from the animals upon which they feed, said Wendy Adams, research grant director for the Bay Area Lyme Foundation, in California. All life stages of the most commonly encountered ticks — the deer tick, lone star tick, Gulf Coast tick and Rocky Mountain wood tick — carried the bacteria that causes Lyme disease, Adams said. “That’s important, because that would say that a tick doesn’t need to acquire an infection from a blood meal. It’s born with the infection,” Adams explained. These findings are the result of an unexpectedly successful effort by the Bay Area Lyme Foundation to collect tick samples from across the country. Between January 2016 and August 2017, the foundation and Northern Arizona University offered free tick identification and testing to the general public. People were encouraged to send in ticks they found on themselves, their pets or around their communities. The scientists’ original goal was to collect about 2,000 ticks. They wound up with more than 16,000, sent in by people from every state except Alaska. “We got such a phenomenal participation,” Nieto said. “Two weeks in May, we got almost 2,000 packages per week. That is just powerful data.” People found ticks in areas not represented in tracking maps maintained by the U.S. Centers for Disease Control and Prevention, the researchers discovered. Most of these new areas were right next to counties with known tick populations, Adams said. “Ticks are spreading. Tick populations have exploded,” Adams said. “This is good data to show the extent of that. It’s a message to people that even if you think ticks aren’t a problem, they could be.” The 24 states that contain counties with newly documented populations of deer ticks or Western black-legged ticks are Alabama, Arizona, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Montana, Missouri, Nevada, North Carolina, Ohio, Oregon, South Carolina, Tennessee, Texas, Utah, Virginia, Washington and Wisconsin. Further, ticks were found in states where they simply weren’t supposed to be, Adams said. Lone star ticks were found in California and black-legged ticks were found in Nevada, both for the first time ever. People also found ticks carrying Babesia — microscopic parasites that infect red blood cells and cause the potentially life-threatening disease babesiosis — in 26 counties across 10 states in which the public health department does not require physicians to report cases of the disease. The new study “highlights the geographic variability of ticks and the pathogens they carry,” said Dr. Paul Auwaerter, clinical director of infectious diseases at Johns Hopkins Medicine in Baltimore. “Surveillance is increasingly important as we see climate and environmental changes, because we do see expanding ranges of ticks. We’ve seen that with Lyme disease. We’ve seen that with babesiosis,” said Auwaerter, president of the Infectious Diseases Society of America. Adams agreed, suggesting that more funding should be directed to these sorts of crowd-sourced tracking efforts. “We have to invest federal dollars to examine the spread of ticks,” she said. In the meantime, the Bay Area Lyme Foundation suggests that people protect themselves from ticks by: Wearing light-colored clothes to make ticks more visible. Do regular tick checks after being in a tick-infested area, and shower immediately after to wash away ticks that might be crawling on you. Consider using tick repellents like DEET for skin and permethrin for clothing. Talk with your doctor if you develop any symptoms following a tick bite. The new study was published online July 12 in the journal PLOS One. More information The U.S. Centers for Disease Control and Prevention has more about ticks.
25 May 2018
FRIDAY, May 25, 2018 (HealthDay News) — Outdoor enthusiasts: Here’s a bit of good tick-fighting news just in time for Memorial Day weekend and the unofficial start of summer. A new U.S. government study confirms that insecticide-treated clothes marketed for preventing tick-borne ills do, in fact, thwart the pests. In lab tests of clothes bought from one manufacturer, researchers found that the garments either quickly caused ticks to fall off, or rendered them unable to bite. The study involved three types of ticks that, in the United States, are major carriers of disease — including Lyme disease, Rocky Mountain spotted fever, and what’s known as southern tick-associated rash illness, or STARI. The clothes were pretreated with permethrin, a synthetic form of an insect-thwarting compound from the chrysanthemum flower. It’s used in insecticide sprays and shampoos and creams that treat lice and scabies. Several companies already market permethrin-treated shirts, pants, socks and other clothing, as a way to ward off disease-transmitting pests. The new study adds to evidence that the garments are indeed toxic to ticks, according to senior researcher Lars Eisen, of the U.S. Centers for Disease Control and Prevention. “All tested tick species and life stages experienced the ‘hot-foot’ effect after coming into contact with permethrin-treated clothing,” Eisen said. That, he explained, made the ticks drop off of “vertically oriented” clothes — which would simulate a pair of pants when a person is standing. In addition, Eisen said, when the ticks were in contact with the clothes for up to five minutes, they lost their ability to move normally — and to bite. There are still questions, he noted, including what types of clothing offer the best protection in the real world. The CDC already recommends permethrin as one tactic for avoiding tick bites. It says that people can “treat clothing and gear, such as boots, pants, socks and tents, with products containing 0.5 percent permethrin.” The agency further says that “pretreated clothing is available and may be protective longer.” Thomas Mather is director of the University of Rhode Island’s Center for Vector-Borne Disease and its TickEncounter Resource Center. He said the new findings, published May 24 in the Journal of Medical Entomology, offer more support for the tick-fighting garments. “This can be a pretty effective way to stop ticks,” said Mather, who was not involved in the study. In his own research, Mather found there are benefits even with permethrin-treated summer clothes that leave some skin uncovered — shorts, T-shirts, socks and sneakers. His team had a group of brave volunteers watch a movie while allowing lab-raised, disease-free ticks to crawl on their bodies. Some wore regular clothes, some wore clothes with permethrin — either pretreated or with the insecticide added using home kits. Those wearing either kind of treated clothing ended up with far fewer live ticks on their bodies by the end of the movie. While people can use permethrin on their regular clothes, the pretreated garments hold up to many more washings, according to Mather — up to 70. Some people may be wary of chemically treated clothes. But, Mather said, the amount of permethrin in clothing is very low: A solution containing only 0.5 percent of the pesticide is “dried into” the fabric. According to the U.S. Environmental Protection Agency, research indicates that permethrin is “poorly absorbed” through the skin, and there’s no evidence that treated clothing could be harmful to children or pregnant women. U.S. military members have been using permethrin-treated uniforms since the 1990s, the EPA noted. According to Mather, the garments may also be a good bet for people whose jobs keep them outdoors — or for gardeners or anyone else who spends time in places where tick exposure is a concern. Eisen pointed to some other CDC-recommended ways to cut the risk of tick-borne ills: Avoid wooded and brushy areas with high grass and “leaf litter”; walk in the center of outdoor trails; use EPA-registered repellents containing ingredients such as DEET, picaridin or oil of lemon eucalyptus; thoroughly check your body and clothes for ticks after being outdoors; and shower within two hours of coming back indoors. More information The CDC has more advice on how to avoid tick bites.