Tick Tock

04.02.14

Cases of New Tick-Borne Illness, Heartland Virus, Grow

Five new cases of Heartland Virus hit Missouri this week. Is it time to start worrying?

Not to be arthropodically incorrect, but I hate ticks.  Those indestructible, hard-shelled, eight-legged arachnids are the exoskeletal but equally creepy version of the spider, the cousin of the scorpion, and the close relative of the mite.

(But please don’t call them insects! Insects are mildly annoying but easy to co-exist with—plus they have 6 legs for Christ’s sake, not 8, and three body sections not two. As if!).

Just like Dracula, Bill Compton, and Edward Cullen, adult ticks live vampirically on mammalian blood. No leafy greens or breadcrumbs will suffice. Rather, they burrow in and can greedily sip blood for days—not like the pesky but much less rapacious mosquito, which flutters in, takes a quick blood meal, and then flies away before you can even swat it. And while dug in, ticks can transmit whatever disease(s) they are carrying.

Because, despite my antipathy, ticks help keep me and other infectious disease specialists stay in business, spreading as they do a long list of infections from Lyme to Rocky Mountain Spotted Fever to babesia (which causes a malaria-like anemia) to tularemia (Rabbit Fever) to ehrlichia (now with the Latin-oid name of anaplasmosis). But dealing with their aftermath is just business, ma’am—I have developed no version of the Stockholm Syndrome in my attitude towards them.

So it is with genuine dread that I have read about the latest tick-borne illness, this one called the Heartland Virus. A report this week from public health experts in Missouri has described new five cases of the infection, which first was recognized in 2012 in Heartland Hospital in St. Joseph, Missouri, once the eastern hub of the Pony Express, then the birthplace of Walter Cronkite, now the epicenter of a tiny epidemic. The global count is about a dozen cases thus far.

Despite its inviting, assuring name, which makes it sound more like a breakfast cereal than a disease, the Heartland Virus causes very unpleasant symptoms including aches and fever and fatigue that last far too long. The disease seems to resemble Chikungunya and Dengue and various other nouveau maladies in its intensity and ability to push a person towards total misery but not death. The virus, carried by the Lone Star tick (which can carry other illnesses as well), is in the virus family called the phleboviruses—the “phleb” prefix refers to veins, indicating literally the source of the ticks’ nutrition. 

The ultimate public health impact of Heartland Virus remains to be seen but is likely to be limited. Ticks and tick-borne illness tend to remain regional though the impact of global warming and suburban sprawl and other man-made perturbations of weather and ecosystem make any semi-accurate prediction impossible. Should the disease spread much though, it is likely to result in a call for a vaccine to reduce risk and assure public safety.

Those eager for a new vaccine to quell public concern and reduce the public health impact of a tick-borne illness though ought to consider the short unhappy tale of the Lyme vaccine, LYMErix™. This now-forgotten intervention was around briefly in the late 1990s before concerns about side effects burst its bubble. The vaccine appeared to prevent about 80% of cases of Lyme, a remarkable achievement, and the FDA—so often criticized for moving with feet of lead—this time acted quickly to approval based on one-year follow-up. The vaccine, which required a several-shot series, was OK’ed with some fanfare and optimism in late 1998.

“Despite its inviting, assuring name, which makes it sound more like a breakfast cereal than a disease, the Heartland Virus causes very unpleasant symptoms including aches and fever and fatigue that last far too long.”

Moving even faster though, in December 1999, a class action suit was filed against the manufacturers of LYMErix™ on the basis of apparent vaccine-induced arthritis. Anti-vaccine sentiment, always present, suddenly had found a winner—a disease (Lyme) that affected people in the areas surrounding the media center of the universe, New York City. At warp speed, Lyme vaccine victims and sad-sack tales abounded on the evening news, the morning paper, and the then-fledgling World Wide Web.  

The coup was swift and bloodless. The LYMErix™ manufacturer quickly gave up and withdrew the product within a few years despite the fact that, according to a leading US vaccine expert, “few, if any, scientists believe the evidence points to any substantive safety concerns”. But actual science was not part of the equation: bad press meant worse sales and the market to prevent Lyme—which has a group proclaiming Lyme to be an overlooked public health catastrophe that is every bit as intense and single-minded as the anti-vaccine crowd—suddenly disappeared.

I suspect that should the Heartland Virus cause real trouble across the US, vaccine manufacturers will move quite slowly into the field—their tick hangover has moved into Tick Hangover II and III sequels and likely will persist for decades more. Contagious diseases can spread quickly, but nowhere near as swiftly as bad information or corporate aversion to risky investment.

It has left us with the strangest of bed-fellows: public health authorities, often suspicious of Big Pharma, now pleading for their help and, equally bizarre, the anti-vaccine and pro-chronic Lyme crowds, many of whom are politically conservative, distrusting the most basic tent of capitalism—the profit motive. As these odd new relationships sort through their issues, however, the public is left to fend for itself with only bug spray, long sleeves and for the strong of heart, perhaps a season or two of True Blood to reconnect us to our inner vampire.