Four-fifths of people in Singapore have not been exposed to H1N1 yet
Jessica Jaganathan, Straits Times 5 Sep 09;
HOSPITALS are on their guard for a possible second wave of Influenza A (H1N1), even as the number of cases dips.
Infectious disease experts estimate that the first wave infected about 700,000 people here. This means more than four-fifths of the population have still not been exposed to the virus.
The estimates were based on the fatality rate of 0.1 per cent - the ratio of deaths within the population - used by the World Health Organisation (WHO) for previous influenza pandemics.
Hospitals are making sure they have enough wards, manpower, medical supplies and infection control measures in place to deal with increased numbers, the Ministry of Health (MOH) told The Straits Times.
Alexandra Hospital, for instance, has been given funds by MOH to convert a private ward with 15 beds into a dedicated H1N1 ward.
The extra ward will double the number of beds that the hospital now has for H1N1 flu patients, who are housed together, separate from other patients. Alexandra needed all the beds at the peak of the outbreak last month.
As of Aug 31, 1,181 people with H1N1 had been hospitalised, with 77 needing intensive care. To date, 17 have died: four had no pre-existing conditions.
Associate Professor Paul Ananth Tambyah, head of the National University Hospital's infectious diseases division, said the numbers were in line with those from other countries and validated Singapore's approach to have pandemic-preparedness clinics look after the vast majority of patients with flu.
The latest fatality was a six-year-old boy, who The Straits Times understands was from Batam, Indonesia, and had sought treatment here for leukaemia.
Dr Wong Sin Yew, an infectious diseases physician in private practice and former head of the Communicable Disease Centre, said it was difficult to estimate how quickly H1N1 had spread compared to the seasonal flu, which is not tested as thoroughly.
But, as in other countries, the majority of those infected, and who were seriously ill or have died, are between 15 and 64 years old.
Dr Natalie Tan Woon Hui, associate consultant of KK Women's and Children's Hospital's infectious disease service, said nearly one in three of Singapore's 1,181 hospital admissions were those aged 14 or below.
She added that children with or without underlying conditions were equally susceptible, though the latter were usually less sick.
The WHO predicts that two billion people will likely be infected worldwide by this new virus, with a 'second wave' expected during winter in the northern hemisphere, the traditional flu season.
Prof Tambyah said this could be anywhere from next month to January for the United States and Europe, and countries with large numbers of travellers from those areas.
But as the virus has not changed much so far, the outbreak is likely to be mild and not drawn out, said doctors.
'When the second wave does occur, those who have been infected with H1N1 are unlikely to be infected again, provided there is no significant mutation,' said Dr Wong.
The ministry is taking no chances, and will have two million courses of the anti-viral drug Tamiflu by the end of this year, almost double the original stockpile. Another 200,000 courses of Relenza will be added to the current 550,000 in the national stockpile.
Singapore has a contract with Australian drug maker CSL for a pandemic vaccine, enough for the population.
