One man died and two others are in a stable condition in Hong Kong after being infected with the hepatitis E virus from rats, prompting authorities to issue a warning about the illness.

The Centre for Health Protection has been investigating three cases of infections in humans of the rat hepatitis E virus and has urged the public to be vigilant against it.

A 74-year-old man with other health issues and who had been admitted to Tuen Mun Hospital on April 28 passed away on May 4, according to a government release. The other two men infected, an 81-year-old and a 67-year-old, both with liver function problems, have been in a stable condition.

The three patients lived in Yau Oi Estate in Tuen Mun, Ma Hang Chung Road in Kowloon City in Kowloon and South Horizons in the Southern District on Hong Kong, Ming Pao Daily reported.

Neither recalled having any direct contact with rodents or their excreta, nor had noticed rodents in their residences. Hong Kong recorded five cases of human infections of rat hepatitis E virus so far this year.

The exact mode of transmission of the rat hepatitis E virus to humans is unknown, but the usual cause is mainly through the fecal-oral route, for example, due to fecal contamination of drinking water.

Health authorities are investigating the source and route of the infections. Meanwhile, they urged the Food and Environmental Hygiene Department to carry out rodent control measures and the public to maintain good personal and food hygiene.