As the second wave of A/H1N1 hit the country, taking on the pattern of a seasonal influenza or flu, health officials urged the public not to panic.
So far there have been 48 confirmed cases since October 6, when the first patient of the second wave was detected in the influenza-like disease surveillance at the Lady Ridgeway Hospital for Children in Colombo, Consultant Epidemiologist Dr. Ranjan Wijesinghe of the Epidemiology Unit told the Sunday Times.
Stressing that the World Health Organization (WHO) has now declared that H1N1 is in the ‘post-pandemic period’ or last phase, he explained that this, however, does not mean that we will not have cases. The virus will continue to circulate for many more years, but the severity will be less.
The important difference between the first wave that hit Sri Lanka in June last year during the ‘pandemic phase’ and the second wave this year is that the virus has joined the pattern of other seasonal flu viruses, he said, adding that H1N1 was the predominantly circulating strain in the first wave.
“Then it spread like wildfire, with people manifesting severe symptoms but now we may not see an unusual breakout. This is because some people have acquired immunity against H1N1 either due to contracting the virus or being vaccinated against it. But it will be seen among clusters of people who are not immune,” he said.
Among those who develop the disease, the individuals who have co-morbidities or health issues such as hypertension and diabetes which make them immune-deficient, may have severe symptoms, said Dr. Wijesinghe.
“Therefore, it is important to think about remedial measures, with the best option being vaccination,” he said.
The vaccines have been distributed to all Medical Officers of Health (MOHs) to be administered to those with the highest risk of catching H1N1 such as health and disaster management workers as well as essential services which include armed service personnel and telecom and electricity workers, the Sunday Times learns.
Anyone with health issues which may make them vulnerable to the virus may also seek the flu shot from the MOH, he said.
The second wave was anticipated following trends in countries in the Southern Hemisphere such as Australia and New Zealand where H1N1 distinctly joined the bandwagon during the flu season. Our surveillance data since 2004 has indicated that we have flu throughout the year but with two major peaks in February-March-April and October-November-December, he said, explaining that with the first wave peaking in the middle of October last year, H1N1 was expected to act similarly this year. This was further strengthened by the fact that cases are occurring in the southern Indian states of Andhra Pradesh, Tamil Nadu and Kerala with much travel between them and Sri Lanka.
In the first wave which hit in June last year with imported cases and the community spread beginning in October and continuing until mid-February this year there were 642 confirmed cases with 48 deaths.
The fortunate factor was that in the first wave only 10% of those who contracted H1N1 needed intensive care unit admission which indicates that the virus virulence was not so bad, he added.