Korean Hemorrhagic Fever (Hemorrhagic Fever with...

Korean Hemorrhagic Fever (Hemorrhagic Fever with Renal Syndrome - HFRS), aka Hantavirus

Hey, US readers, have a good Labor Day weekend? Go camping? Have a cook-out?

Statistically, the Labor Day holiday is by far the most popular time of year for families to go camping, and one of the most popular (and coveted) places to secure a reservation is Yosemite National Park cabins and “signature” tents. Unfortunately, this year, there’s been a bit of an outbreak of the Hantavirus pulmonary syndrome in the Curry Village section of Yosemite. There have only been six recorded cases so far, but many more may have been missed, as it can imitate severe pneumonia, and other diseases that doctors are more familiar with. Luckily, it’s not communicable from person-to-person, but the deadliness of the disease and length of incubation (up to 6 weeks) has lead the CDC and US Parks Service to send out a mass warning to those who stayed in the park this summer.

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This isn’t the first time the US has had to cope with Hantavirus, though. In the Korean War (1950-1953), UN troops (largely the US military at that point), the first instances of Westerners becoming infected by this deadly infection were recorded.

As the virus is carried by deer and cotton mice and their close relatives, and those mice are keen to scavenge human scraps, there was much left-behind urine, feces, and saliva of those rodents in rather ill-equipped military encampments. These are the same family of mice that are suspected of spreading the virus in Yosemite.

However, in Korea, the most common pathological presentation of the virus was the “Hantavirus hemorrhagic fever with renal syndrome”, or HFRS, which, while much more survivable than Hantavirus pulmonary syndrome (8-15% mortality versus ~35% mortality rate, respectively), was debilitating, and ended up costing the UN hundreds of thousands of dollars in convalescence costs for soldiers. Even after the war, the search for the cause of the “Epidemic [Korean] Hemorrhagic Fever” took another two decades of research, before Ho-Wang Lee of South Korea discovered the species of Bunyavirus that caused both soldier and civilian infection throughout the 1950s, 60s, and 70s.

Even today, we don’t know of a cure for infection by Hantavirus, and can only provide supportive treatment to patients while their bodies defeat the disease on their own. The ability to support bodies coping with the renal syndrome has significantly improved, but the Hantavirus pulmonary syndrome is as deadly as ever, especially the strains found in the United States. For an unknown reason, patients who contract the Sin Nombre (Four Corners) Virus seem to have a particularly difficult time developing antibodies against it in time to defeat the disease, despite generally being young and healthy.

Though the soldiers who fought across the globe over half a century ago may seem to be completely disparate from the kids and young parents camping in the national parks today, the outbreaks in their platoons are what sparked the search for the cause of a (generally rare) hemorrhagic fever that’s thought to have existed across the globe for centuries, and the discovery of the cause and vector of transmission will hopefully soon lead to an effective cure against the many forms the disease can take, saving the lives of people in impoverished countries and the wilderness of wealthy parts of the world alike.

Images -
Top: Non-fatal case of epidemic (Korean) hemorrhagic fever, showing extensive hemorrhage of the conjunctiva. Otis Archives, National Museum of Health & Medicine, 1950.
Bottom: Patient suffering from hemorrhagic syndrome. From the memoirs of Dwight Raymond Johnson, US Korean War medic, 1953.