The Health Protection Center (CHP) of the Hong Kong Ministry of Health announced on August 24, 2021 that it is closely monitoring a case of bubonic plague in Ordos, Inner Mongolia Autonomous Region.

According to the Ordos Health Commission, a farm worker was diagnosed with bubonic plague on August 21. She remains in critical condition. However, close contacts of the patient remained asymptomatic and tested negative for plague.

A CHP spokesperson said: “Plague is transmitted from an infected animal (rodents) to humans through the bite of their fleas.”

“Plague can also be contracted when cuts or other lesions of the skin come into contact with the bodily fluids or tissues of infected animals.”

“Eating infected animal tissue and inhaling infected respiratory droplets are also a possible mode of transmission.”

Patients infected with bubonic plague usually present with fever, headache, and painful swelling of regional lymph nodes, especially around the groin. The infection can progress to septicaemic plague when the bacteria invade the human bloodstream.

The spokesperson reminded travelers to avoid visiting plague-endemic areas.

“Travelers returning from affected areas with a sudden fever, chills, body aches or chest discomfort should seek medical attention as soon as possible and disclose their travel history for prompt investigation and management.” added the spokesperson.

Plague is an ancient disease that killed millions of people, including a third of Europe’s population during the Black Death pandemic in the 14th century. Plague remains a threat in many parts of the world and has been classified by the World Health Organization as a re-emerging disease.

According to the US CDC, more than 80% of plague cases in the United States were bubonic. Over the past few decades, an average of seven cases of human plague have been reported each year. Most human cases in the United States occur in two regions: northern New Mexico, northern Arizona, and southern Colorado; California, southern Oregon and extreme western Nevada.

Prophylactic vaccination against this disease is certainly a primary choice, but the US FDA has not approved one. New plague vaccines are in development but are not expected to be commercially available in the immediate future, according to the CDC.

In this 2019 review published by the journal Nature, advances in plague vaccine research and development were presented.