A targetted approach in managing H1N1 cases

29 Jun 2009, The Straits Times

Question

Judicious testing now

MADAM Ong Tze Lin was puzzled yesterday why her husband was not tested for Influenza A (H1N1) at Tan Tock Seng Hospital, even though he might have been a contact of a confirmed case in the Maju Camp cluster ('Not tested for virus despite contact risk').

Reply

Reply from MOH 

Influenza outbreak follows certain progression. As many patients can be infectious even without symptoms, community spread of the virus is the inevitable outcome. However, the pace of such a progression is not identical among countries. In North America, where the outbreak first broke out, they had no opportunity to contain the outbreak. They were forced into mitigation measures immediately. Outside North America, all countries were able to implement containment measures. Such measures cannot prevent community spread, but can significantly slow down the pace of local transmissions. This is useful as we can avoid a sudden surge in cases that might overwhelm hospitals and clinics. Two months after the outbreak, many countries, including Japan and Australia, have already moved into full-scale mitigation phase as community spread has gone into full swing.

Singapore has avoided community spread for seven weeks, but has begun to see many locally infected cases, with community spread likely to go into full swing soon. We are, therefore, moving from containment to mitigation phase. The practical implications of the shift are many. For example, the definition of 'close contacts' and the need for laboratory testing of 'close contacts' are progressively being tightened. When we were in full containment mode, we widened the definition of 'close contacts' and subjected everyone to laboratory testing. We are now preparing to manage the disease in a more targeted and risk-stratified manner. In some hospitals with experienced infectious disease specialists, they are beginning to use clinical judgment to decide who constitute 'close contacts' and who should be tested.

In the case of Madam Ong's husband, the doctor must have decided his exposure was very low. Nevertheless, we advise him to keep a watch on his health and to alert us immediately should it worsen.