LLyme Disease was established in Lyme Connecticut nearly 50 years ago. However, the tick-borne infection is now widespread. New study published in BMJ Global Health estimates that 14.5% of the world’s population has, at some point, been infected with Lyme disease, which can cause short-term symptoms including a skin rash, fever, headache, and fatigue—as well as long-term ones, including damage to the joints, heart, and nervous system.
It appears that the scourge is getting worse. From 2001 to 2010, Lyme prevalence doubled between 2010-2021.
This meta-analysis, conducted by scientists at the Institute for Tropical Medicine, Kunming Medical University (China), was performed to analyze 89 papers dating back from 1984 through 2021. The papers contained blood samples taken from almost 160,000 individuals who had been tested. Borrelia burgdorferi,The Lyme disease is caused by a spiral-shaped bacteria. Any one of a variety of blood tests was used to analyze the samples, such as the ELISA, which detects antibodies in blood, and the IFA, which employs a fluorescence test to perform the same function. Western Blotting is considered to be more reliable than the other methods. This method looks for protein in the blood that could indicate infection with the target virus or bacteria. The Western blotting method is thought to reduce the incidence of false positive results, but it has a major drawback: it’s less sensitive in the early stages of Lyme infection than ELISA or IFA. Out of the 89 selected studies, only 58 utilized Western Blotting.
The fact that Lyme has been reported in nearly 15% of the population is quite remarkable. “[Lyme disease] has become the most common tick-borne zoonotic disease worldwide,” the researchers wrote. “There is a need for preventive measures, which necessitates understanding the dynamics of tick-borne disease transmission and the lack of effective disease-prevention strategies.”
The leading reason Lyme rates have doubled over the past decade is climate change. Higher temperatures and longer springs and summers increase ticks’ range and the amount of time people spend outside. “Tick populations,” the researchers write, “have expanded globally and geographically in recent years, thereby greatly increasing the risk of human exposure.”
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Lyme disease is a condition that can be contracted from any location. Central Europe had the highest rate of Lyme disease, 21% of its population. Eastern Asia was second with 16% and western Europe third at 13.5%. Oceania was the least at 5.5%, followed by southern Asia at 3.3% and then the Caribbean at 2.2%. With 9.4%, Americas came in somewhere between. Part of the reason for the variance is the differing presence of Lyme-bearing ticks in various parts of the world, but other factors played a role in who is likely to contract the disease and who isn’t.
The risk of developing cancer in older people was higher than that for those younger. The 18.1% of people tested positive for Lyme disease in the study were older than the 17.6% and 9.5% respectively in the groups 40-49 and 39 years. Researchers did not suggest a reason, although weaker immune systems may have played a part.
It’s not surprising that rural residents were more at risk than urban dwellers. 12.6% positive tests came from rural people, while 8.1% came from urbanites. Although the researchers didn’t break down their data according to occupation, they speculated that farmers, soldiers and homemakers might be more exposed to ticks than those in urban areas.
There are many methods to detect Lyme disease. The results can be muddy. Western blot tests tend to produce lower total figures. This 14.5% number is an average of a 9.8% and 17.5% respectively using ELISA/IFA. Similar ranges exist when it is about age. ELISA and IFA show an 18% prevalence in 50-plus, compared to 8.8% for Western blot. Newer and still under development molecular diagnostic tools could help to confirm Lyme diagnosis.
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