As eager as we are for the picnics, barbecues and pool parties to begin, we know the danger posed by Lyme disease, West Nile virus and other insect-borne illnesses is already lurking. This summer, there is even a new tick-borne disease out there—a distant yet-to-be named cousin to Lyme disease reported by Yale researchers in January.
The good news is that the risk of getting Lyme disease from a recognized tick bite is relatively low, says Yale pediatrician and epidemiologist Eugene Shapiro, MD. Only one to three percent of those who recognize they’ve been bitten get the disease—usually when they see the “bulls-eye” rash a week or two later. “That’s because most ticks are not infected, and if a tick is infected, it has to feed for some time before it can transmit Lyme Disease,” says Dr. Shapiro. “For a nymphal tick, it’s 48 hours or longer before the risk of transmission is great. For adult ticks, it’s 72 hours or longer. So, if you see the tick before that and pull it off, you most likely will not get the disease.”
Of course, Dr. Shapiro says, “It’s the tick you don’t see that poses the greatest risk.”
West Nile virus disease is even less common—there were 21 cases reported in Connecticut last year, compared with 1,654 reported cases of Lyme—although that is notably the most severe outbreak of West Nile since the virus was first detected in the state in 1999, and more than double the cases reported in 2011. “In my practice, there’s more regional concern about Lyme. In Connecticut, it’s very common to know someone who has had it,” says Matthew Grant, MD, a Yale infectious disease specialist.
You are less likely to get these diseases if you take precautions and see a doctor quickly with suspicious symptoms. A few things to look for:
West Nile virus: You may experience no symptoms at all, or you may turn out to be the one out of five who develop a fever. A minority have headaches, body aches, joint pains, vomiting or diarrhea. More worrisome is that the disease can lead to encephalitis or meningitis, and can be life-threatening especially to the elderly and the chronically ill. There is no vaccine or specific antiviral treatment, although over-the-counter pain relievers can be used to lessen some symptoms.
Lyme disease: Symptoms vary. You may notice an expanding red or bull’s eye rash at the site of the bite, as well as flu-like symptoms such as chills, fever, body aches, fatigue and headaches. The latter symptoms are so common and nonspecific that they can make diagnosis difficult. But untreated, early Lyme disease can develop into arthritis, or neurologic or cardiac disorders. Talk to your doctor about whether you might have Lyme disease. If the disease is diagnosed, the doctor will typically prescribe doxycycline or amoxicillin, or, rarely, intravenous antibiotics. Yale’s Peter Krause, MD, a tick-borne disease researcher, recommends talking to a doctor about a single dose of doxycycline for adults and children 8 years and older in certain circumstances following a deer tick bite.
A new Lyme-like disease: In January, Dr. Krause, Yale researchers Erol Fikrig, MD, Durland Fish, PhD, and Sukanya Narasimhan, PhD, along with colleagues from other institutions, reported in the New England Journal of Medicine the first description in the United States of the occurrence, frequency and clinical manifestations of a tick-borne infection that shares many similarities with Lyme disease. This disease, which is still rare, is caused by the bacterium Borrelia miyamotoi, and causes many symptoms similar to Lyme, although there may be other symptoms, such as a relapsing fever. Blood tests for this infection are only available in a few laboratories, but many laboratories are planning to offer the test in the near future. The disease is treated with the same antibiotics that are used for Lyme disease.
While it helps to be aware of these diseases, Dr. Shapiro says they shouldn’t keep you from going outside this summer. “The anxiety is as large a problem, or larger, than Lyme disease itself,” he says. “There is a lot of misinformation in the lay press and on the internet, and misdiagnosis is rampant. The thing to keep in mind is that Lyme disease is fairly easy to diagnose and cure, and if it’s treated effectively there is little risk of long-term complications.”
The trick is to be careful, says Dr. Grant. He’s had personal experience. After a hike on the Connecticut shoreline, he and his wife checked themselves for ticks in the parking lot and found a nymphal tick on his lower right shin. He used a pair of tweezers to remove it. “Ticks need to be engorged to infect you, so if you go on a hike, spot a tick and then remove it immediately, you don’t have to worry,” Dr. Grant says.
To make an appointment at Yale Infectious Diseases call 203-785-3561.