Experts from the Shaanxi Provincial Center for Disease Control and Prevention have urged residents to seek immediate medical treatment if they have symptoms of hemorrhagic fever with renal syndrome, or HFRS, such as fever, headache and vomiting.
Since the beginning of winter, multiple hospitals in Xi'an, the provincial capital, have seen a significant increase in HFRS patients compared with average years, as well as an uptick in severe cases and fatalities, the center said in a statement last week.
In an interview with Health Times on Sunday, the center said the disease is generally transmitted to people by rats or mice that carry hantavirus through biting or direct contact with rodent saliva, urine or feces.
Illness begins abruptly, with high fever, hemorrhage and kidney damage. Severe cases can be fatal.
Striped field mice, a species that can carry hantavirus in the wild, are relatively common in central Shaanxi.
The disease is seasonal, with the peak period from October to March, and over 80 percent of patients are found in rural areas, the center said.
Efforts to reduce rat and mice populations and enhance public health awareness have been strengthened in Shaanxi and in other places that have seen cases of HFRS, including Luoyang in Henan province.
"HFRS is a common infectious disease in northern China and seldom causes human-to-human transmission," Zhu Xin, an infectious disease expert at Luoyang's center for disease control and prevention told Luoyang Daily. "After the flood disaster in summer, a large number of rats migrated to the highlands, which also caused the spread of the disease.
"Before the 1980s, there were HFRS epidemics in Luoyang, with patients concentrated in rural areas along rivers. However, with the improvement of the rural living environment and people's health habits, the incidence rate has dropped sharply, especially in the past decade."
Zhu added that some scattered human infections had been reported in villages in mountains in the southwest of the city, with most of the patients over 50 years old.
He advised villagers to keep food in cupboards, refrigerators or airtight containers, and avoid coming into contact with rodents or their excreta.
Free vaccinations will be provided to rural residents aged between 16 and 60 in key areas with a high incidence of the disease in central Shaanxi, the provincial center for disease control and prevention said.
Vaccination can effectively reduce the incidence of HFRS and reduce the severity of the disease, it said.
Data from the Chinese Center for Disease Control and Prevention shows that 678 HFRS cases were reported in October, with 5 deaths. Last year, there were 8,121 cases and 48 deaths in China, with an average fatality rate of 0.59 percent.