Community transmission of H1N1

We saw the biggest local increase (26) in influenza A(H1N1) cases yesterday, raising the national total to 103. There are now 4 cases where H1N1 transmission is believed to have occurred within Singapore itself, including 2 teens who are doubtlessly still schooling. How this happened seems fairly clear-cut for 1 case - his family had dropped by from the Philippines (although reportedly none had been symptomatic) - but not for the rest. The MOH website gives a few more details about the other cases. Perhaps the teens became infected as a consequence of meeting up with friends who had returned from other countries, or perhaps the transmission occurred just because they were in areas where many people congregated (like church functions or shopping malls) and where there were other infected individuals. The 4 cases of local transmission were identified mainly because of the polyclinic influenza surveillance program (where patients with influenza-like illnesses are swabbed regardless of travel history) and alert GP's.

But what this means is clear - the new H1N1 virus is loose in the community. The containment strategy is no longer viable. Whether it has served its purpose is another matter. Community transmission in Singapore has been delayed for a few weeks at the cost of millions of dollars. The time bought with this strategy has enabled us to learn more about how this virus has "behaved" in other countries, and therefore to understand its risks and significance (or lack thereof). Today's news on local transmission and the largest increase in newly diagnosed cases only made Page 6 of the Straits Times (moreover only able to take up a full page because of a very large Robinson's advert), whereas a few weeks ago, it would have been front page with many accompanying stories and expert opinions. There is certainly less public anxiety now.

There was a clear and sufficiently long window for public education, but unfortunately the messages seem to have been rather mixed. Based on ST and MOH press reports alone, most people would probably not have had a clear picture of the severity of this new H1N1 outbreak, nor been able to judge whether official response was appropriate (a rough gauge would be forum postings on the topic of H1N1). If we agree that the virus is not worse than seasonal influenza, why quarantine so many people and hospitalize all with the disease? Why castigate people who travel to affected countries (there are now so many that you could not really leave Singapore without ending up in one of them)? If this is to prevent excess morbidity and mortality, why not do the same for all other influenza cases? If we remain unsure about viral virulence (well, we really should not be too uncertain after so many weeks and so much shared experience from other countries), why step down or talk about mitigation?

Perhaps the containment phase will continue a bit longer. Just so that we can officially convince ourselves that H1N1 is truly in the community (also, the delegates for the Asian Youth Games are in town and it would probably be bad karma to export H1N1 from Singapore via this group of athletes, officials and accompanying persons). Perhaps schools can be closed for a further week after the end of the June holidays. The latter more than anything else will delay the spread of H1N1 in Singapore. But we will have to ask ourselves whether it is now worth such an effort. The other argument for delaying the outbreak is always in the background - that the healthcare system will be overwhelmed by the large surge of cases. Data from other hard hit countries such as US and Australia suggest otherwise. In fact, the number of outpatient visits for influenza-like illness in the US has dropped below the national baseline. But efforts to prevent the system from being overwhelmed may result in an eventual "own goal": as of yesterday, there remain 73 H1N1 patients in our hospitals that would not even have been hospitalized if they had seasonal influenza - these patients do take up beds and significant healthcare workers' time (they have to gown, glove and mask up every time before even entering each individual patient room). Hospitals may have to cut electives and expand on emergency and isolation resources (and these may come with a trade-off in terms of efficiency of care for other medical conditions). If past pandemics are any judge, we are looking at another 1 to 4 years of this virus circulating around before it becomes just another "seasonal influenza".