A second person has died of bubonic plague in a US state.
The victim, aged in his twenties, passed away on Friday after being taken to a local hospital in Rio Arriba County, New Mexico, for treatment.
In June, a man in his 60s was also diagnosed with the condition but recovered in hospital.
Health officials are now investigating the home and family of the young man that died of the rare infection.
It is not yet known how the pair managed to contract the disease.
Authorities say the two men lived more than one hundred miles apart and believe it is unlikely the cases are linked, the Mirror reports.
New Mexico Department of Health Secretary Kathy Kunkel said: "Plague activity in New Mexico is usually highest during the summer months, so it is especially important now to take precautions to avoid rodents and their fleas which can expose you to plague".
The World Health Organisation (WHO) estimates there are between 1,000 and 2,000 cases of plague around the world every year.
Roughly 30 and 100% of those cases prove fatal, according to the WHO.
Bubonic plague is a bacterial disease spread by fleas living on wild rodents like marmots.
Sufferers will then develop abdominal pain, diarrhoea and vomiting and some people will bleed from their mouths, noses or rectums.
It kills in less than 24 hours if not treated promptly.
Up to 200 million people were killed by the Black Death in the 14th century.
Earlier this month, a fourth person died from the bubonic plague in Mongolia, prompting neighbouring Russia to vaccinate thousands against the disease.
The 42-year-old man, from the Khovd province, died after purchasing two infected marmot rodents which are seen as a food delicacy, according to reports.
