Nearly 15% of the World's Population Has Likely Had Lyme Disease, a New Analysis Finds
As the summer nears, we anticipate an increase in seasonal pests, including ticks. These critters technically belong to the arachnid family, home to spiders, and some species are also responsible for transmitting Lyme disease to humans. This ailment is far more pervasive than we realized: After conducting and researching 90 studies, new findings published in the journal BMJ Global Health uncovered that over 14 percent of people have likely had this tick-borne condition in their lifetime. "As far as I'm aware, this is the first global seroprevalence [measurement of antibodies in blood] work that's been done," Dr. Peter Krause, a senior research scientist at the Yale School of Public Health, who is unaffiliated with the study, told NBC.
To reach these findings, the research team—based at The Institute for Tropical Medicine, Kunming Medical University, in Kunming, China—rounded up nearly 90 studies for an amassed pool of over 158,000 people. These studies identified how common antibodies from the bacteria Borrelia burgdorferi, which causes Lyme disease, are in humans. Nearly 23,000 individuals had these antibodies, which means they likely had Lyme disease at the time of the testing—or did at one point in their lives.
Per the team's regional data, residents in Europe and North America are most likely to contract Lyme disease via ticks. However, the analysis found that Central Europe had the highest percentage of infected locals, nearing 21 percent. In comparison, just nine percent of people in North America have experienced Lyme disease. Study participants also resided in Asia, Australia, the Caribbean, Europe, and North and South America. The Caribbean had the least amount of people with Lyme disease, coming in at two percent.
The ticks that spread Lyme disease to humans are most attracted to deer and typically reside in warm, humid conditions—mainly in wooded areas, like forests. Longer summers, a result of climate change, are also prompting tick populations to ramp up and spread. Symptoms of Lyme disease include a rash that typically appears three to 30 days after getting bitten, fever, chills, headache, fatigue, and muscle aches. The bite itself can appear up to 12 inches wide and have a warm feeling.