April 1
More than 200 residents of Hong Kong's Amoy Gardens apartment complex, to which SARS has spread, are sent to quarantine camps.

April 2
The World Health Organization urges travelers to avoid Hong Kong and China's southern Guangdong province.

April 3
The Chinese Minister of Health disputes the WHO travel warning, denying that the Chinese government was slow to release information on the disease.

April 4
Li Liming, director of the Chinese Center for Disease Control, issues an apology for his country's handling of SARS. "Our medical departments and our mass media suffered poor coordination. We weren't able to muster our forces in helping to provide everyone with scientific publicity and allowing the masses to get hold of this sort of knowledge," he says.

President Bush issues an executive order allowing forced quarantine of people who have been exposed to SARS. The order also names cholera, diphtheria, infectious tuberculosis, plague, smallpox, yellow fever and viral hemorrhagic fevers such as Ebola, Lassa and Marburg. White House spokesman Scott McClellan says there are no plans to use the quarantine authority at this time. "This is just to make sure we are prepared for any eventuality," he tells reporters.

April 9
Dr. Jiang Yanyong, a retired chief of surgery for a Beijing military hospital, accuses his government of covering up the extent of SARS infections in Beijing. He says medical staff at two other hospitals told him at least seven deaths have occurred in their facilities, and that there were 106 SARS cases in Beijing, more than five times the number of cases announced. The Chinese Health Ministry had reported four deaths and 19 cases in Beijing.

April 10
Singapore places a 10-day quarantine on arriving foreign workers from regions hard-hit by SARS and steps up enforcement of quarantine orders on hundreds of people suspected of exposure to the virus.

Hong Kong says anyone who resides with a confirmed SARS patient will be quarantined for up to 10 days. Health Director Dr. Margaret Chan says police will make unannounced visits to homes to ensure people don't violate their quarantine.

April 16|
The WHO contradicts the Chinese government's claims that it is including cases in military hospitals in its tally of patients with SARS. WHO team member Dr. Wolfgang Preiser reports "there indeed have been cases of SARS, there is no doubt about that, that have not been reported officially, in that the military seems to have its own reporting system that doesn't link in presently to the municipal one."

Alan Schnur, head of communicable disease control in WHO's Beijing office offers a "guesstimate" that Beijing has 100-200 SARS cases -- far more than the 37 publicly reported. The WHO also reports that a new form of the coronavirus family -- also the source of the common cold virus -- causes SARS.

April 18
China's Communist Party leadership declares an all-out war on SARS, ordering officials to fully disclose the extent of the disease's spread. The move comes after accusations that China has masked the extent of the SARS outbreak within its borders and only half-heartedly cooperating with international efforts to combat the disease.

April 23
The WHO warns against travel to Toronto, Beijing and China's Shanxi Province as the number of SARS cases in those areas continues to rise.

April 28
The SARS outbreak appears to have peaked in Singapore, Hong Kong and Canada and has been successfully contained in Vietnam, the WHO reports. But the U.N. agency also cautions that the disease is still spreading in China.

April 29
The WHO announces that starting on April 30 it will lift the warning against unnecessary travel to Toronto that it imposed on April 23 amid fears over the spread of the SARS virus.