Lyme disease figures soar, mostly in Northeast

US estimates 300,000 cases yearly

Deer ticks were blamed for  3,342 confirmed Lyme disease cases reported in Massachusetts last year.
Courtesy of UMASS Amherst
Deer ticks were blamed for 3,342 confirmed Lyme disease cases reported in Massachusetts last year.

New estimates indicate that Lyme disease is 10 times more common than previous national counts showed, the federal government announced Monday, with about 300,000 people getting the disease each year — most in the Northeast.

The updated total, compiled by the Centers for Disease Control and Prevention, is based on data from health insurance claims, laboratories, and public surveys. Past estimates of 30,000 cases a year relied on physicians’ reports to states, and the illnesses were widely considered underreported.

Lyme, spread by the bite of deer ticks, is now about as prevalent in the United States as reported cases of gonorrhea and more common than syphilis and whooping cough.


The CDC did not break out the new Lyme numbers by state, but the estimate would appear to translate into at least 40,000 new infections a year in Massachusetts.

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The higher estimate is expected to increase political pressure for more government funding to combat the disease.

“This new preliminary estimate confirms that Lyme disease is a tremendous public health problem in the United States, and clearly highlights the urgent need for prevention,’’ said Dr. Paul Mead, chief of epidemiology and surveillance for CDC’s Lyme disease program. He said scientists have known since the 1990s the number of cases was underreported by three- to 12-fold but did not have a good handle on exactly how greatly until now.

The new numbers were presented at the 2013 International Conference on Lyme Borreliosis and Other Tick-Borne Diseases, being held this week at Harvard Medical School.

Lyme disease has spread throughout Massachusetts and New England in recent decades after first being identified in a group of children in Lyme, Conn., in the mid-1970s. Deer ticks — often found in areas that are forested or overgrown with tall grass — can infect people with Lyme and four other known pathogens.


Early symptoms of Lyme include fever, headache, fatigue, and a skin rash that looks like a bulls-eye. A short course of antibiotics cures most cases if caught early, specialists say, but if the infection is left untreated, it can spread to joints, the heart, and nervous system, resulting in arthritis, facial palsy, tingling, and other symptoms.

Lyme disease is controversial. As its numbers have grown, so has an enormous divide between Lyme patients and the medical establishment over whether the disease is chronic and antibiotics should be used long-term to manage symptoms. Confounding the issue are tests that can sometimes be inaccurate.

Lyme disease activists say the new numbers are hardly surprising, but they hoped the news would motivate government officials to push for more funding for tick control and prevention. A bill is pending in Massachusetts to expand the authority of mosquito control districts to kill ticks too.

“Everyone in New England knows someone who has Lyme disease,’’ said state Representative David Linsky, a Democrat from Natick who spearheaded a state special commission on Lyme disease that earlier this year called for more funding.

“We need more funding and research and more doctors to understand and treat Lyme disease,” Linsky said.


Based on physician reports, there were 3,342 confirmed and 1,708 probable Lyme disease cases last year in Massachusetts, a 19 percent increase over 2011. In comparison, last year there were 33 human cases of West Nile virus and seven cases of eastern equine encephalitis, which are both transmitted by mosquitoes. Nationwide there were 5,674 cases of West Nile virus last year and about 15 cases of EEE.

Lyme and ticks appear to be a low priority for public health authorities here — and nationwide. More than $10 million is spent each year in Massachusetts to control mosquitoes. Tick-borne diseases receive only about $60,000 annually in state funding. National numbers were not available, but tick specialists say funding is much less than for mosquito control.

State public health officials also said the numbers were not surprising. “We have always known we were nowhere close to the actual numbers,’’ said Katie Brown, state public health veterinarian.

The CDC arrived at the new estimate from three sources: insurance claims data for 22 million Americans from 2005-2010; positive test results from large labs that test for Lyme; and population surveys asking whether respondents had been diagnosed with the disease in the past year.

The agency said it is still analyzing the data and will publish its final estimate when the studies are complete. In the meantime, officials are working to get the message out on prevention and, along with the US Environment Protection Agency, have begun discussions about how to control ticks on a community-wide basis. They acknowledge that it is challenging to do so effectively, because ticks are so widespread.

CDC’s Mead said many infectious diseases are underreported for various reasons and the paperwork involved for doctors may discourage many from reporting Lyme. However, he said that does not mean those cases went undiagnosed and untreated — they were merely not counted by the federal government.

Beth Daley can be reached at Follow her on Twitter @GlobeBethDaley.