The World Health Organization has expanded its investigation of the outbreak of Severe Acute Respiratory Syndrome in China with more visits to rural areas, where the outbreak is feared to be worse than officially acknowledged.
World Health Organization officials are worried that thousands of migrant workers who work in some of the worst affected areas may have spread SARS to their impoverished hometowns.
Teams are being dispatched to provinces with high numbers of migrant workers.
Investigators are in the southern Guangxi province that borders Guangdong, which has a high number of infections. Experts are expected to leave for Anhui in central China and Henan this week.
China has officially reported few cases in the provinces, but the WHO suspects the situation may be worse than stated. Many of the provinces have poor health care systems and little way to accurately identify and report SARS cases.
WHO investigations have previously focused on the capital, Beijing, neighboring Hebei, and the southern province of Guangdong, where the disease is believed to have originated.
China reported 75 new SARS cases, bringing the total to more than 5,000. In China, 252 have died from the illness.
The number of new infections in Hong Kong remained in single digits with only five cases reported, and three deaths.
A decline in infections has prompted many residents to stop wearing surgical masks and raised hopes that travel advisories against the territory may soon be lifted.
Hong Kong Hospital Authority senior executive manager Liu Shao-haei calls for continued vigilance against SARS. "Whether we take off our face masks or not is something just symbolic," said the official. "The important message in my view is that we must be able to monitor adequately the development of the spread of this disease. We need to have a good monitoring system to prevent further outbreaks so our efforts must be sustained."
In Taiwan, the number of new infections continued to increase. On Monday, the government reported 23 new cases, the biggest one-day jump since the outbreak began two months ago.
SARS causes serious pneumonia and has yet no cure or vaccine. More than 7,000 people have been infected by SARS worldwide, and more than 500 have died.