About 2.2 percent of patients who underwent dialysis in 2001 were infected with the hepatitis C virus because some facilities apparently failed to take proper precautions to prevent infection, according to a government study, which did not identify the institutions were the infections occurred.

The research team at the Health, Labor and Welfare Ministry that conducted the study said the results suggest that thousands of people could be newly infected with the virus each year in such ways.

The Japanese Society for Dialysis Therapy and the Japanese Association of Dialysis Physicians said they have sent emergency recommendations to member institutions, asking them to take sufficient steps, including not sharing medicine among patients.

The study was conducted at dialysis facilities nationwide. The research team did not name the institutions where patients were infected.

Of the roughly 52,000 people receiving dialysis therapy who had tested negative for hepatitis C at the end of 2000, roughly 1,100 suddenly tested positive at the end of 2001.

As there are around 230,000 dialysis patients in Japan, the survey suggests several thousand are infected each year with hepatitis C at facilities.

The survey shows that at the majority of facilities, there were no newly infected patients, and it is only at certain facilities that fail to take proper measures that the infection rate is high.

The researchers said calls for improved measures have been made in particular to facilities where patients have been newly infected in the past year or where more than a third of the patients have hepatitis C.

The researchers said the most important warning is to not share medicine. The study of group infections nationwide suggests that the main cause of infection was the sharing among several patients of medicine such as mass-produced blood anticoagulants, they said.