Tick-borne babesiosis is a less well known but potent disease


Babesiosis is about the closest most Americans will ever come to experiencing malaria, and like malaria its symptoms range from crippling to lethal to none at all. Both are vector-borne diseases (mosquitoes in the case of malaria and deer ticks for babesiosis).

Both diseases infect the spleen and liver; the symptoms are similar; the pathogens are closely related and are treatable by the same drugs. However, babesiosis is one of the lesser known tick-borne diseases: not that it doesn’t occur, but doctors outside of tick hotspots may not know much about it or know when to look for it.

It’s not too surprising that I came down with babesiosis last summer; what is surprising, is that I got cured. For that, I credit the Red Cross.

Although there is no FDA-licensed test to screen blood for babesiosis at this time, the Red Cross does selectively test blood donations and conducts research studies. A few weeks after I donated, I got a letter in the mail, informing me that I had tested positive for babesiosis.

I hadn’t felt particularly sick; sure there were times I’d felt better, but there were also times I’d felt worse and still had to go to school. I called up Island Health Care, who squeezed me in for a blood test that same day. They prescribed atovaquone, a drug known as malarone when it’s used to treat malaria. I took the drug, felt better, and two months later tested clean.

Just because I didn’t look sick, doesn’t mean I didn’t have the disease. If my blood had been given to someone who was already sick from something else, it could have killed them. Old people are especially susceptible; so are HIV patients, little kids and people without a spleen. Since 1979, transfused babesiosis has infected at least 70 people, of whom 12 died, according to the Red Cross.

The Red Cross conducted a study in which it tested more than 27,000 blood donations from 2000 to 2007. The results were published in the December 2009 issue of the journal Transfusion. Of 1,481 unique donors from the Vineyard, 21 were positive, or 1.4 percent. The actual rate may be higher, since sick people are discouraged from donating blood. In other words: you probably don’t have babesiosis yourself, but you almost certainly know someone who does.

Doctors who are unfamiliar with this specific tick-borne disease may not realize how nonspecific the symptoms are, and they may be reluctant to test someone who’s not acutely ill. This is a classic public-health problem: if the only reason people get tested for a condition is that they’re sick, it is possible to underestimate the prevalence and overestimate the severity.

The off-Island doctor who I went to for a follow-up screening clearly thought I was being silly. He had never known a case of babesiosis in a healthy person. That’s another reason to go to see a doctor familiar with the range of tick-borne diseases.

In the case of Island Health Care, a clinic located in Edgartown, not only were they kind and competent and efficient and they accepted Mass Health, but they also know the Island and its particular health threats.

Babesiosis is spread by deer ticks, like Lyme, and it can be prevented the same way. Cover up when you’re outside, use insect repellents with DEET, Frontline your pets if they go out, and get a mirror or a friend to check the spots you can’t see. A shower can help sweep away ticks that haven’t had time to attach, if you do it as soon as you get home.

But even taking all the precautions, you may never see the tick that gets you. If it also has Lyme, you may get a bulls-eye rash. Sometimes you don’t, sometimes you do and it’s in your scalp. Symptoms are frustratingly nonspecific and easy to miss: unless you’re acutely ill with shakes and chills and an enlarged spleen, you may just feel kind of crummy. Or you may feel great.

If you live or travel somewhere with endemic deer ticks, you may well have been exposed. Healthy people who get babesiosis are more often asymptomatic than not.

Want to know more? Try Google Scholar, online at scholar.google.com. It’s basically a Google search of the scientific literature on any topic you care to name. Most papers have a publicly-accessible abstract, or summary, which is all that a nonscientist is likely to need. The specific pathogen is Babesia microti, if that helps.

I haven’t found much data on long-term babesiosis. Tick-borne diseases tend to occur together. It’s hard to tease out the effects of babesiosis, Lyme, and ehrlichiosis, especially since diseases often interact in complicated ways. However, babesiosis doesn’t always go away on its own. One patient in a Block Island study developed symptoms two years after testing positive, and there’s no way to know when he was originally infected.

Babesiosis is in many ways a silent disease, like Lyme, that often causes no symptoms but is still infectious and dangerous. We thus must be proactive to inform and protect ourselves. Remember, no one cares more about your health than you do.

Maia Smith lived in Aquinnah for seven years, and visited almost every year starting in 1985. Now studying biostatistics at Drexel University, she maintains close ties to the Island.