Health officials are investigating a human case of plague confirmed in Pueblo County, Colorado. Although, no information about who contracted the disease, nor how or when, has been provided. The Pueblo Department of Public Health and Environment (PDPHE) is working with the Colorado Department of Public Health and Environment to investigate, a press release said.
"We advise all individuals to protect themselves and their pets from plague," said Alicia Solis, program manager of the Office of Communicable Disease and Emergency Preparedness at PDPHE.
Plague is a disease that affects humans and other mammals and is caused by the bacterium, Yersinia pestis, according to the Centers for Disease Control (CDC). An average of seven people in the US each year contract the plague, which is spread when an infected rodent flea bites a human or a person handles an infected animal - in some cases is can also be passed through inhalation.
"The more common risk of exposure in the U.S. is from pets, rodents and fleas," said Erica Susky, a certified infection control practitioner based in Canada. Susky adds that hunting, including skinning animals, is also a risk. Overall, the best prevention is to avoid rodents and fleas whenever possible, as well as dead rodents.
"One way to do this is to ensure the home is rodent-proof by eliminating places where rodents may enter and hide,” said Susky. "If spending time outdoors where one may be bitten by fleas and other insects, repellent should be applied to minimize potential bites, which are a portal of entry for the bacterium if one is bitten by an infected flea.”
The plague is found on all continents except Oceania, though most human cases since the 1990s have occurred in Africa, according to the World Health Organization (WHO). It naturally occurs in areas of the western US, as well as certain regions of Africa and Asia, but can be cured with antibiotics if treatment is quickly given.
According to the organization, about 1,000 to 2,000 cases of plague are reported to them each year across the globe with nearly 600 deaths occurring between 2010 and 2015.
The disease is notorious for having caused the Black Death, a devastating global epidemic that is estimated to have killed roughly 50 million Europeans in the mid-1300s.
Modern sanitation and public-health practices have helped slow the impact of the disease but it has not been eliminated. The bacterium was first introduced in North America around 1900 from rats on ships that came from South Asia, estimates Timothy Brewer, M.D., professor of medicine and epidemiology at UCLA.
"Since its introduction 120 years ago, it has become endemic in ground squirrels and rodents in the rural Southwestern U.S.," said Brewer.
“The reason why it hasn’t been eliminated is because there’s an animal reservoir,” adds Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center. “The bacteria can infect animals, and because we can’t treat all animals in the wild, it persists in nature and thus occasionally causes a limited number of human cases.”