A case of the plague has emerged in Idaho - here's why the disturbing disease continues to re-appear
- A child in Idaho came down with the plague recently, according to a statement by Idaho's Central District Health.
- People still catch the plague every year, usually after coming into contact with fleas that carry plague bacteria.
- There are a few cases every year in the US and more in other parts of the world.
A child in Elmore County, Idaho, has been diagnosed with the plague, according to a statement by Central District Health in Idaho.
This plague case, like others that appear rarely but with some regularity, is the same disease that was responsible for the medieval "Black Death." Plague continues to be a serious and potentially fatal bacterial illness. But fortunately, if it's caught early enough, it can be treated with antibiotics.
The Idaho child is recovering after receiving treatment, according to the health department. Officials aren't sure whether the child was exposed to the disease in Idaho or on a recent trip to Oregon.
There are a few plague cases every year in the US, mostly in the rural West and especially the Southwest. The Idaho Central District Health's statement said that since 1990, there have been two cases in Idaho and eight in Oregon. However, according to the Idaho Department of Fish and Game, there was a plague outbreak south of Boise from 2015 through 2016 that affected animals.
Over the past few years, a few cases of plague have been recorded annually in New Mexico as well.
How plague spreads
Plague is spread by fleas that carry the Yersinia pestis bacteria, which can cause the three forms of plague: bubonic, septicemic, and pneumonic. Flea bites spread bubonic or septicemic plague, which both cause fever and weakness. Bubonic plague results in painfully swollen lymph nodes, while septicemic plague happens when the infection gets in the blood and causes skin and tissue to turn black and die. It can appear on its own or develop from bubonic plague.
Untreated, patients can develop pneumonic plague, the most serious form of the disease, which spreads from person to person when infected people cough tiny droplets into the air.
Most of the time, people are exposed to plague when they or their pets go near wild or dead animals carrying fleas that are hosts to Yersinia pestis bacteria.
"People can decrease their risk
by treating their pets for fleas and avoiding contact with wildlife," Sarah Correll, an epidemiologist with
Central District Health Department, said in the statement about the infected child.
Still, the US only gets a handful of cases - usually between one and 17 every year. When a case does crop up in the US, disease detectives try to find every person an infected individual came into contact with.
Plague is a bigger problem in places that have a harder time shutting down outbreaks due to a lack of infrastructure, humanitarian crises, or ongoing conflicts, according to the World Health Organization. Those outbreaks, like a recent severe one in Madagascar, can become more dangerous.
Why plague persists
In wild rodent populations that harbor the bacteria, plague can thrive for a long time before humans come into contact with it.
Ken Gage, a researcher focused on vector-borne disease at the Centers for Disease Control and Prevention, told NPR in 2014 that there are a number of rodents in the American West that are susceptible to plague. That list includes rats, voles, and ground squirrels, all of which can be found in Idaho. In rural areas with semi-arid forests and grasslands, these animals spread the disease amongst themselves.
"What we see in the West here is the fleas will crawl up to the entrance of the burrow and wait for a host to come by," Gage told NPR. "If they get on another rodent that they can live on, then they've been successful. But they can also jump on humans, or on dogs, or coyotes, or cats, which aren't the right hosts, but unfortunately those animals can be bitten by the fleas and get plague."
In the 1400s, approximately 50 million people died of the Black Death. Plague is still one of the scarier infectious diseases out there, with a mortality rate between 30% and 60% if untreated. But fortunately, antibiotics make it possible to treat most cases now. Between 2010 and 2015, there were around 584 plague deaths around the world.
