Following up on last week’s post about the advance of dengue: I’ve been keeping track of new news regarding other diseases transmitted by insects and arthropods, but haven’t had a chance to write them up. So here’s an end-of-year round-up. It’s not cheery (are my posts ever cheery?), but maybe it will prompt some New Year’s resolutions to wear repellents and long pants outdoors. These diseases are no fun.
An Old Disease Returns: Dengue Is in Florida and May Be Heading North
This month, Slate has been running an intermittent series on pandemics under the guidance of new science editor Laura Helmuth. The latest entry in the series is one that I wrote (my first time writing for Slate, which is exciting). It’s about the under-appreciated threat to the United States of a disease that we barely think about: the mosquito-borne illness called dengue, formerly known as “breakbone fever.”
Dengue was once endemic in the United States. When I started researching it for this piece, I discovered a whole series of historical outbreaks I knew nothing about: Charleston, SC, 1828; Savannah, Ga., 1850; Austin, 1885; Galveston, 1897; most of Louisiana, 1922; Miami, 1934. Dengue was not eliminated here until the government undertook mass mosquito-eradication programs in the 1940s, because mosquito-borne illnesses were making so many military members so sick that the toll was hampering the war effort. (Public-health history buffs: Those were the campaigns that gave rise to the CDC, which grew out of a government agency called the Office of Malaria Control in War Areas.)
The Outdoors Hates You: More New Tick-Borne Diseases (ICAAC 1)
This week I’m at ICAAC (the Interscience Conference on Antimicrobial Agents and Chemotherapy), a massive infectious-disease and drugs meeting that is sponsored every year by the American Society for Microbiology. ICAAC is an unabashed scary-disease geekgasm, the kind of meeting at which the editor of a major journal tweets from one room, “‘Modern medicine will come to a halt’ in India because of catastrophic multi-drug resistance” while a microbiologist alerts from another: “Rat lungworm traced to salads on a Caribbean cruise. Snails had apparently gotten to the greens.”
Meanwhile, I was learning more about ticks.
A New Tick-Borne Illness, and a Plea to Consider the Insects
In the summer of 2009, two men from northwest Missouri showed up at Heartland Regional Medical Center in St. Joseph, tucked up against the Kansas border 50 miles north of Kansas City. The men were seriously sick. They had high fevers, fatigue, aches, diarrhea and disordered blood counts: lower than normal amounts of white blood cells, which fight infection, and also lower than normal platelets, cells that control bleeding by helping blood to clot. But they had none of the diseases that were high on the differential diagnosis, the list of possible causes that doctors work their way down as they try to figure out what has gone wrong: no flu, no typhus, no Clostridium difficile, and none of the serious foodborne illnesses — no Salmonella, no Shigella, and no Campylobacter.
The two men had one thing in common, though: About a week before being hospitalized, each remembered, he had been bitten by a tick.
Tick-Borne Infections Infiltrate U.S. Blood Supply
Allow me a tiny I Told You So. In February, I wrote a story for SELF Magazine about the rising incidence of diseases other than Lyme that are caused by tick bites. (And told you about it here, of course.) The story highlighted one particular tick-borne parasite, Babesia, and a serious problem with the infection it causes, babesiosis: that it was moving into the blood supply. We dug through FDA transcripts and CDC field reports in order to reveal that federal health authorities were very concerned about this prospect, and that more than 100 babesiosis infections caused by transfusions had already occurred — not just in the few states where the tick species carrying Babesia are found, but throughout the United States because blood products are shipped nationwide.
Ours was the first reporting we could find about babesiosis in the blood supply, and it didn’t get the attention it should have, probably because women’s magazines tend to be dismissed as not-serious — even though SELF’s health and medical reporting has won prizes and been turned into books. But based on research released this morning, our story at SELF wasn’t hyping the problem. If anything, we understated it.
OK, enough infomercial. Here’s the news: In a paper released ahead-of-print by the Annals of Internal Medicine, researchers from the Centers for Disease Control and Prevention, Rhode Island and New York State report that 159 cases of babesiosis were caused by transfusions in the past 30 years and “the risk may be increasing.” Twenty-seven of the patients died.
The dangers of ticks: Not just Lyme disease
I have a story in the forthcoming March issue of SELF Magazine that has just been put up online: The Rising Dangers of Ticks. It’s a long look at the under-appreciated other diseases that can be transmitted by tick bites — that is, not the Lyme disease that most people associate with ticks, but babesiosis, erlichiosis, anaplasmosis, and others. From the story:
“We’ve seen pretty dramatic increases,” says Jennifer McQuiston, an epidemiology team leader in the vector-borne disease division of the Centers for Disease Control and Prevention in Atlanta. “We’re told to get out and exercise and enjoy nature, so we need to be aware.” Most people have heard of Lyme disease, which appeared among residents of that town in Connecticut in the mid-1970s and now affects more than 35,000 Americans per year. Most Lyme cases occur in the Northeast and upper Midwest; if you don’t live there, you might be safe from Lyme but still at risk for other diseases. Cases of a tickborne illness known as ehrlichiosis grew from 200 to 957 nationwide—a 378 percent jump—between 2000 and 2008, according to the CDC. The infection anaplasmosis nearly tripled in the same period, and Rocky Mountain spotted fever quintupled. The new disease STARI (southern tick-associated rash illness) has spread across the South, and strains of an infection called rickettsiosis have hit the Gulf and Pacific coasts.
All of these non-Lyme tick diseases attack victims in a similar way, bringing on fever, headache, and muscle and joint pain—making it easy to misdiagnose them as anything from flu to meningitis, says [Gary P. Wormser, M.D., the chief of infectious diseases at Westchester Medical Center and New York Medical College and head of a team researching tick diseases]. If the patient remembers finding a tick, or develops a rash, that’s a big clue. If not, “it is somewhat common for these to be missed. The symptoms resemble so many other common viral infections,” says Gregory A. Storch, M.D., a pediatric infectious-disease specialist at Washington University in St. Louis, which created a multidisciplinary tickborne-disease research team because cases have surged there.
…[B]ecause medical awareness has not kept up, patients have been overlooked, undertreated and taken by surprise when their enjoyment of the outdoors—a hike, a run, a round of golf, their own backyard—turns into a life-altering threat.
Sometimes these infections can be transmitted by a tick bite at the same time as Lyme, making them what physicians and Lyme patients call “co-infections.” Sometimes they are mistaken for Lyme. Some of them require different drugs to treat, so if they are not diagnosed correctly, people will not be treated properly and the diseases can linger.
That’s especially important for one of them, babesiosis, because it is caused not by a bacterium but by a parasite that lives in red blood cells much as malaria does — in fact, one researcher described it to me as “American malaria.” Because many people don’t show obvious symptoms, babesiosis isn’t always detected and treated. As a result, it is spreading, both from women to their children prenatally, and also, troublingly, through the blood supply. Babesiosis is currently the No. 1 cause of infections transmitted through blood transfusion in the United States. Unlike other infections that are potentially passed by blood, such as HIV and West Nile virus, there is no test for babesiosis that blood banks can use.
In 2007, in a case that rang alarm bells, a cancer patient in California arrived at the hospital weak and throwing up blood. Tests revealed babesiosis: He had been infected by blood from a man who had donated in Maine, say Van P. Ngo and Rachel Civen, M.D., epidemiologists at the Los Angeles County Department of Health who investigated the case. The FDA has since reported that over the past 10 years, babesiosis has infected more than 100 Americans via transfusions—and 11 of them have died.
These are tiny numbers compared with the more than 5 million people who receive transfusions in the United States each year. But there are almost certainly more cases than there would be if blood banks could effectively check for the parasite. Right now, donors merely complete a questionnaire that asks whether they have had babesiosis or unexplained fever. In one study in Connecticut, 1 out of every 100 donors who passed that screening was shown to be potentially infectious.
These infections aren’t often deadly, but sometimes “deadly” isn’t the point: For many of the women (and men) who have had them, they are life-interrupting and sometimes life-changing, requiring tough drug treatment and long recovery times. A number of women who suffered from babesiosis and erlichiosis generously shared their stories with me, and two are featured in SELF. I hope you’ll take a look.