Experts in southwest China's Yunnan Province have started a medical investigation into a possible hantavirus outbreak in a local county after a man who tested positive died Monday; the man was traveling by bus on his way back to east China's Shandong Province for work.

The bus, which set out from Cangyuan County, had 33 people aboard, including two drivers, one medical staff, and 30 migrant workers. The man, surnamed Tian, was one of the workers. He developed symptoms at around 4:00 a.m. on Monday when the bus went through Ningshan County of northwest China's Shaanxi Province.

Tian and two others with fever symptoms were then taken to a local hospital. Four hours later, Tian died after testing positive for hantavirus. The other two were tested negative for the virus and cleared of the novel coronavirus infection as well. The rest of people on the bus are under medical observation.

Zuo Shifu, one of the experts on the team, told CGTN that they have just arrived at Cangyuan County where they will conduct a local epidemiological investigation to screen out possible hantavirus outbreak. Zuo said, from 2015 to 2019, Yunnan Province had recorded a total of 1,231 cases of hantavirus infection, with one death, but there has been no reported case in the county before.

Hantaviruses are a family of viruses which are spread mainly by rodents and can cause various diseases in people. It can cause hantavirus pulmonary syndrome (HPS) and haemorrhagic fever with renal syndrome (HFRS). The disease is not airborne and can only spread to people if they come in contact with rodent urine, feces, or saliva and less frequently by a bite from an infected host.

The virus can't be passed on from person to person, and is classified in China as causing Class B infectious diseases. Early symptoms include fatigue, fever, and muscle aches, along with headaches, dizziness, chills and abdominal problems. If left untreated, it can lead to coughing and shortness of breath and can be fatal.

Zuo said vaccination is the most effective way to prevent hemorrhagic fever, as the vaccine has been available in the country for nearly 20 years. He added that it's important to keep good hygiene and keep living environments clean, eliminate rodent habitats, and strengthen personal protection to prevent skin damage.

(Cover: Sin Nombre hantavirus particles. /VCG)