Cases of a tick-borne disease known as mumps are becoming much more common in the United States, according to a new report from the Centers for Disease Control and Prevention (CDC). Babesiosis is transmitted by black-legged ticks, also called deer ticks, and can cause flu-like symptoms in some people and potentially fatal infections in others.
Until recently, mumps was relatively rare, the CDC said. But in 10 states, up from seven states about a decade ago, mumps is now considered endemic — meaning it's an epidemic disease that's an ongoing, ongoing threat.
“This marks an unfortunate milestone in the emergence of babyism in the US,” he says Peter Krause, MD, a senior researcher at the Yale School of Public Health in New Haven, Connecticut, who was not involved in the CDC report. “It's worrying because this disease can be serious or life-threatening in immunocompromised people.”
Babezosis is also spreading west and south
The CDC reported that mumps cases more than doubled from 2011 to 2019, reaching endemic levels for the first time in Maine, New Hampshire and Vermont. Babesiosis was already at endemic levels in seven states: Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin.
Nine other states that previously had no cases or only rarely reported cases of babesiosis are now seeing more cases of the disease, even though the levels of cases are still considered low, the CDC said. These states include Delaware, Illinois, Iowa, Maryland, North Dakota, Ohio, South Dakota, Virginia, and West Virginia.
Why are cases of mumps increasing?
Several factors make mumps more common, says Dr. Krause. One culprit is global warming and increased rainfall, which are contributing to the expansion of the black-legged tick population. Increases in the population of white-tailed deer, a common food source for ticks, are also contributing, Krause says. An aging population is also leading to an increased caseload, with the elderly being more vulnerable to infection, as well as more homes being built in areas closer to ticks.
Most cases of mumps in the United States are caused by blacklegged tick bites, Ixodes scapularis, in the northeastern and midwestern states, the CDC said. The same ticks can also transmit Lyme disease. Babesiosis can also be spread through blood transfusions, organ transplants from infected donors, or from infected pregnant parents to their babies.
Although most cases are not caused by blood transfusions, people who acquire mumps through contaminated blood have significantly worse outcomes and a higher risk of death than people who get it from tick bites, the CDC said. U.S. regulators already recommend screening donor blood for mumps in 14 states and Washington, D.C., according to the CDC, and regulators are continuing to evaluate whether screening may be needed in additional states.
Symptoms, Tests and Treatment for Babesiosis
Symptoms of mumps may begin within a week of exposure and may continue to develop for several weeks or months, according to the CDC. Many people have no symptoms at all, but some people may develop flu-like symptoms, including fever, chills, sweats, headache, body aches, loss of appetite, nausea, and fatigue. Because the parasite that causes mumps infects red blood cells, this disease can also cause anemia.
Mumps can be serious or even fatal for certain groups, including people who are elderly, have weakened immune systems, or live with serious chronic conditions such as kidney or liver disease, the CDC says.
Babesiosis can be detected by a blood test and can be treated with antibiotics. “Fortunately, early diagnosis and treatment will lead to a complication-free cure for most infected people,” says Krause.
How can I prevent deer bites and infection?
Mumps can be prevented in many cases by taking precautions when spending time outdoors, he says Bobbi Pritt, MD, MSctick-borne disease researcher and chair of clinical microbiology at the Mayo Clinic in Rochester, Minnesota.
“The best way to prevent mumps and other tick-borne diseases is to avoid tick bites,” says Dr. Pritt. “This can be done by avoiding areas where ticks are found, such as tall grass, using tick repellent and covering exposed skin with clothing.”
The CDC also suggests several other ways to keep ticks off your body when you spend time outdoors. These include:
- Watch where you walk. Stay on clear paths and try to stay away from overgrown grass, piles of leaves and brush where ticks tend to be found.
- Cover your skin. Wear long pants, long sleeves, high socks and tuck them all inside so ticks can't easily get into your clothes.
- Use tick repellent. Apply products containing DEET directly to clothing or skin. Products containing permethrin can also be applied to clothing, but not to the skin.
When you're done outside, daily checks are essential. Ticks must remain attached to a person for more than 36 hours before they can spread the parasite that causes mumps, according to the CDC.
How to check for ticks — and why it's necessary
Here's the best way to check for ticks, according to the CDC:
- Remove ticks from clothing and pets before going inside.
- Use a mirror to inspect every part of your body, including around the groin, between the toes, behind the ears, and in and around your hair.
- Remove ticks with fine-tipped tweezers.
“People need to take tick-borne diseases seriously and protect themselves from tick bites,” says Pritt. “However, they should not stop doing things they enjoy outdoors, as there are many health benefits to being active and enjoying nature. By taking simple steps such as using tick repellent and performing frequent tick checks, people can greatly reduce their risk of contracting a tick-borne disease.”
