A small Oregon county has been struck by one of the rarest but scariest ailments known to exist. Health officials in Hood River County have reported an unusual cluster of people coming down with Creutzfeldt-Jakob Disease, or CJD.
Three residents in the area have contracted CJD over the past eight months, according to the Hood River County Health Department, two of whom are already dead. Local and federal health officials are now investigating the cluster, but they have not identified a link between the cases to date.
CJD and similar brain diseases are caused by a misfolded version of the naturally occurring prion protein. When these rogue proteins come into contact with their harmless brethren, they convert them into more misfolded prions, acting almost like a zombie invasion. The accumulation of prions steadily destroys the brain, though it can take years or even decades for symptoms to appear. Once they do, however, death quickly follows.
Thankfully for humanity, prion ailments are rare (other prion-like diseases might be more common). While CJD is the most common prion disease, only around 500 new cases of it are estimated to happen in the U.S. annually. This rarity makes three cases showing up so close together in the same relatively small county (roughly 24,000 people live in Hood River) all the weirder.
CJD can broadly happen in three different ways. It can be passed down from mutations that make the emergence of prions inevitable. It can be transmitted, though usually only through rare scenarios such as close contact with infected brain tissue. Or it can simply occur sporadically for no clear reason.
Most CJD cases fall in the last bucket. But over thirty years ago, there was an outbreak of CJD caused by tainted cow meat (this specific form of CJD came to be known as variant CJD). As it turns out, the cows were infected with their own version of a prion disease—a condition formally called bovine spongiform encephalopathy, but more memorably known as mad cow disease.
The mad cow/vCJD outbreak was contained by the mid-1990s, and only a few hundred people were ever sickened by prion-infected beef. But it showed that prion diseases can be more transmissible than we thought, and even today, scientists still worry about the possibility of similar events happening again. In North America, for instance, a prion disease has been steadily spreading among deer in recent years, though there is no solid evidence yet that it poses a threat to people.
For that reason, anytime a cluster of CJD does appear, it tends to set off public health alarms. The bunching together of these cases in Hood River, Oregon—one confirmed, two suspected—might simply be pure, if unlucky, coincidence. But it remains important to rule out the scarier scenario. For now, there’s no immediate signs of something more being amiss.
“At this time, there is no identifiable link between these three cases,” the Hood River County Health Department said in its latest statement on the cluster, released Monday.
The health department is still monitoring the situation, in conjunction with the Oregon Health Authority (OHA) and Centers for Disease Control and Prevention (CDC). But as they rightly note, the general risk of CJD to the public is very low.
