Flu Season in Myanmar

Living Well in Myanmar

The flu shot:  Knowing when and why to get it

In most countries doctors face the challenge of convincing patients to get vaccinated against the flu. In Myanmar we face the additional challenge of determining the right time of year to offer the flu vaccine. Because the efficacy of the flu vaccine wanes slowly after it has been administered, patients should get the shot in the season in which flu is most common.

We know from disease surveillance data that in cool-climate countries in the northern and southern hemispheres the flu season occurs in the winter months. In contrast, in tropical climates the flu season is more variable, with cases of the flu often occurring year-round. This makes recommending the timing of a flu shot more difficult in places like Southeast Asia.

A new report published in the Bulletin of the World Health Organization is helpful in this regard. The authors collected and reviewed data on the occurrence of the flu from 2006 to 2011 in 10 Southeast and South Asian countries. For the three nations closest to the equator – Indonesia, Malaysia and Singapore – cases of the flu seemed to be spread evenly throughout the year. In countries slightly further to the north – Bangladesh, Cambodia, India, Laos, the Philippines, Thailand and Vietnam – there was a clear uptick in flu cases from July to October. These months, of course, correspond to our rainy season.

While Myanmar was not included in the research, a look at our neighbouring countries Thailand and Bangladesh shows that July, August and September have been the highest intensity flu months in recent years. Until Myanmar has it’s own data, we can probably safely extrapolate that this is the time in which we will benefit most from vaccination. Therefore, it makes sense for doctors to encourage patients to get vaccinated in May and June. 

Vaccine manufacturers formulate separate vaccines for the northern and southern hemispheres. They attempt to target the strains of the influenza virus that are most likely to occur in each temperate climate’s winter season. In an average year the vaccine will protect against 80 percent of circulating virus strains. The southern hemisphere version is produced in Australia and is given in April and May in preparation for the winter. Because this is close to the timing we feel is most useful in Myanmar, we administer the southern hemisphere vaccine in my clinic. Even if international residents living in Yangon were vaccinated in Europe or America last autumn, they may not be adequately protected against the flu during rainy season and should consider getting this vaccine.

In most cases the flu makes you feel crummy for a few days to two weeks – fever, weakness, headache and bone pain are common symptoms. But it can lead to more serious complications such as pneumonia, bronchitis, ear infections or sinus infections. Children are particularly vulnerable to the flu, while the elderly account for most of the annual deaths caused by flu-related complications. Another high-risk group is pregnant women. Research has taught us that there is twice the risk of fetal death in women who get the flu while pregnant.

There is no truly effective treatment for the flu. Rest, analgesics and hydration are used while we wait for the symptoms to dissipate on their own. Furthermore the flu is often indistinguishable from Dengue, so the sickness that characterises both diseases may require blood tests to make a diagnosis. For these reasons patients should have a conversation with their doctor in Myanmar to decide if the vaccine is right for them.

gelsdorfMD@gmail.com  © Christoph Gelsdorf 2013