Babesiosis, a potentially deadly tick-borne illness that mimics malaria, is on the rise in the suburbs north of New York City, according to a paper published in the May issue of the Emerging Infection Disease Journal.
The disease has also spiked in coastal Rhode Island, Massachusetts, Connecticut and Long Island. At least 1,000 cases have been reported, mostly in the Northeast and the upper Midwest, and for those who are immune-compromised, it can be fatal.
And it's not a new malady, according to Dr. Gary Wormser, chief of infectious diseases at New York Medical College and co-author of the paper.
"One of the earliest reports of this condition is in the Bible and the Plagues of Ten that were imposed on the evil pharaoh of Egypt," he said.
Six cases first appeared in the Lower Hudson Valley in 2001 and by 2008, there were 119 cases, according to the paper, a 20-fold increase.
Most people weather the disease with virtually no symptoms or after effects -- which is precisely why public health officials are worried.
Babesiosis can go undetected in the blood supply -- putting those who are sickest at risk -- and there is no widely used screening test.
Of those who are hospitalized for babesiosis, 1 in 20 dies, according to Wormser. "It's a lot like malaria at its worst."
Symptoms include a high fever, as well as a powerful headache.
"It's variable," he said. "Some people get over it spontaneously and other people get really sick," he said. "At times it's really life-threatening."
The disease is caused by the parasite babesea microti, which invades and destroys the body's red blood cells, according to the Centers for Disease Control and Prevention (CDC).
An estimated 1,000 cases are reported each year, but experts say many more go undiagnosed.
The parasite is relatively new to the Lower Hudson Valley, where Lyme disease has been much more prevalent, according to Wormser. Those cases that were seen, were "imported" from Long Island and Nantucket.
"How it got here is a mystery," he said.
Those with HIV/AIDS, cancer patients undergoing chemotherapy and the elderly are also at risk for the more virulent form of babesiosis. People who have had their spleen removed because trauma or cancer, are also more susceptible.
Experts speculate that, like Lyme disease, babesiosis has spiked because of the surge in the deer population in residential areas.
Because both diseases are carried by the deer tick, some get Lyme disease and babesiosis simultaneously, which can make a correct diagnosis even more difficult.
Those who do experience symptoms report a mild to moderate flu-like illness that can last just days or up to six months.
Those who donate blood tend to be robust and without symptoms, and can therefore pass transmit the disease.
Babesiosis is the most frequently reported infection transmitted through blood transfusions and has caused at least 12 deaths nationwide in the last decade. There were six deaths in New York City alone in 2009.
Currently the only way to screen is to use a questionnaire and ask blood donors if they are infected.
Rhode Island, which has seen the tick-borne disease since 1999, is the first state to try an experimental test after several infants developed babesiosis following blood transfusions.
Since last July, the Rhode Island Blood Center has screened blood as part of an investigational new drug (IND) use protocol sanctioned by the Food and Drug Administration (FDA).
"We think [babesiosis] is under reported and we don't know how many real cases there are," said Dr. Carolyn Young, the center's vice president and chief medical officer.
"We select about 3,000 units of blood that would be intended to go to neonates and pediatric sickle cell patients and those with pediatric thalassemia," she said.
So far, no cases of the disease have emerged among these babies and the IND data will be used to support an application for potential FDA-licensed test.
Diagnosing the disease can be difficult, according to Dr. William Schaffner, head of preventive medicine at Vanderbilt University Medical School in Tennessee
"It's a pretty darn unusual infection," he said. "It's the sort of illness known to infectious disease specialists, but most general doctors are clueless because until recently, it was an oddity."
Laboratory technicians can spot the "bug" under the microscope and often mistake it for malaria, according to Schaffner. "It takes a very sophisticated eye to distinguish the two."
"For the most part, it doesn't know how to make us sick," he said. "If you are young and healthy you may never know you have an infection and it comes and goes all by itself."
Disease symptoms can include chills and sweats, headache, muscle and joint pain, loss of appetite and the tell-tale fever.
"They go back to the patient history and delve into the patient's family or friends, who say he went fishing or golfing or hiking in the woods, clearing brush on the estate," said Schaffner.
Treatment includes a combination of selected antibiotics and quinine, a malaria drug.
Preventing tick bites in the first place is the key, according to Schaffner. Use tick repellant consistently, even in the backyard, if there is brush.
Have a friend or family member check for ticks on the body -- "Your back, hair and hairline at the neck and always check under your arms," he said. "The belt line and the groin are favorite places ticks like to crawl.
If a tick is found, "take a tissue and grasp the tick firmly and gently pull," he said. "Don't jerk."