Increase in number of flu cases at polyclinics: MOH

Increase in number of flu cases at polyclinics: MOH
By Monica Kotwani  Posted 01 Aug 2016 16:56 Updated 01 Aug 2016 17:11

SINGAPORE: A recent spike in the number of flu cases is being caused by a strain that few in Singapore have immunity against.

Dr Leong Ho Nam, an infectious diseases expert at Mount Elizabeth Novena Hospital, said this in an interview with Channel NewsAsia following the release of latest figures by the Health Ministry showing an increase in the number of acute upper respiratory infections (ARI) seen by polyclinics in July, compared to June.

Dr Leong said Singapore's flu season parallels that of countries in the southern hemisphere, such as Australia. He said people may have picked up the virus while travelling in Australia during the school holidays in June.

"We have a new strain of influenza H3N2, and this has taken in not just Singapore but also the whole world. We see a lot of it between the different countries, spreading around as travellers move from one place to another. This is also a new strain. A lot of people are naive to it, in that we have not experienced this before."

In a statement to Channel NewsAsia, the Health Ministry confirmed there is "evidence of increased influenza activity in recent weeks from the rise in the proportion of cases where influenza viruses have been isolated". It said the rise is consistent with what is typically seen during the flu season, which lasts between November and February and May and August each year.

SIX-MONTH HIGH IN ACUTE UPPER RESPIRATORY CASES

According to the Ministry's weekly infectious diseases bulletin, the number of people visiting polyclinics for acute upper respiratory infections, characterised by symptoms such as a cold, cough and sore throat, hit a 6-month high of 3,427 cases for the week ending Jul 23.

In early June, weekly ARI numbers hovered at around 2,600 cases, before increasing to about 3,000 for the week ending June and early July. Since then, figures have hovered in the 2,900 range, before peaking in the third week of July.

In contrast, the number of patients visiting polyclinics with such symptoms stood at between 2,300 and 2,400 cases for each week in July last year.  More people also presented such symptoms last month compared to median July figures for the years 2011 to last year.

Despite the increase in flu activity, MOH said that influenza only accounts for less than 5 per cent of the total number of ARI cases. "Acute respiratory infections (ARI) are very common and are caused by a large number of different viruses, including influenza," the statement said.

Some general practitioners Channel NewsAsia spoke to confirmed they had seen an increase in the number of patients with such symptoms in the last two to three weeks. Dr Tan Tze Lee, a GP at the Edinburgh Clinic, said symptoms seem to be more "uncomfortable".

"We're seeing more cases of high fevers in patients - of 39 and 40 degrees Celsius. The typical runny nose, cough and sore throat are also more uncomfortable. And they're taking longer to clear," he said. Another GP Channel NewsAsia spoke with, who declined to be named, confirmed this trend at his clinic.

POOR 'HERD IMMUNITY' FOR H3N2

After a genetic mutation to the strain was discovered in 2014, H3N2 became the most prevalent strain for almost all of 2015 in Singapore. This year, H3N2 again emerged as the dominant strain among those who tested positive for the flu in June. MOH said that of specimens that tested positive for influenza that month, more than 80 per cent came back positive for the influenza A (H3N2) strain.

Dr Leong said despite the local population being exposed to the virus, it takes "a few years" for it to make its rounds, and for people to built up their herd immunity against it.

A vaccine for the strain has been available since October 2015, according to Dr Leong.

However, there has been a poor uptake, with less than five to 10 per cent of the population vaccinated. "For good protection, you need at the barest minimum 60 to 80 per cent of the population coverage and we are clearly not reaching that  So in terms of herd immunity protection, it is very poor. One can pick it up, and in turn, spread it to colleagues and the risk of transmission of the influenza virus is very fast and very easy," he said.

GET VACCINATED

Dr Leong said he expects the number of flu infections to remain high throughout the rest of the year, mainly because of a lack of immunity against the virus, a low vaccination rate and the start of the flu season in the northern hemisphere.

MOH said most people with the flu recover with rest and "symptomatic treatment", but urged young children, pregnant women, the elderly and those with chronic illnesses to get vaccinated.

- CNA/mo


- wong chee tat :)