Even with COVID-19 still around, we need to be protected against the flu (influenza) and the serious complications it can cause. The Department of Infection Prevention & Epidemiology from Singapore General Hospital (SingHealth) explains.
Dr Ling Moi Lin, Director of Infection Prevention & Epidemiology from Singapore General Hospital (SGH), a member of the SingHealth group, shares why it is important to stay flu-safe amidst the COVID-19 pandemic.
How many flu seasons do we have in a year?
You always seem to hear that it's flu season time (again) in Singapore. Why?
"The flu season occurs between fall and winter seasons around the world. Divided into the Northern and Southern hemispheres, the flu virus is different for both sides of the equator. For us in sunny Singapore, we are (un)lucky enough to be right in the middle of both Northern and Southern hemisphere changes, and thus we are affected by both the prevailing flu strains!" explains Dr Ling.
"The months that we (in Singapore) are affected typically range from
May-July and December-February," she adds.
Types of flu virus
The flu (influenza) virus can be categorised into 3 types (A, B and C). Types A and B are responsible for seasonal epidemics (and flu vaccines are designed to combat these stronger types of the flu virus), while Type C only causes mild respiratory illness.
Here are the differences:
Can cause significant disease |
Generally causes milder disease but may also cause severe disease |
Infectious to humans and other species (e.g. birds; H5N1) |
Limited to humans |
Can cause epidemics and pandemics (worldwide epidemics) |
Generally causes milder epidemics |
The Type C virus only causes mild respiratory illness so it is not a cause for concern.
"As the influenza virus is a living organism, it constantly adapts to the environment and conditions in order to stay alive. That is why
it is important to refresh your flu vaccination every year," Dr Ling explains.
How is the flu spread?
The flu (influenza) is spread mainly in two ways:
Person to person: When a person with influenza spreads droplets through coughing and sneezing (droplets can propel up to 1m through the air)
Through touch: A person can become infected by touching an object or a surface that has the influenza virus on it and then touching their mouth, eyes or nose
With relaxation of COVID-19 measures and the resuming of international travel, it is no surprise that flu cases in Singapore are seeing a rise.
"That is why it important to get flu vaccinated as the virus can spread even when no symptoms are present* (asymptomatic)," Dr Ling shares.
How to tell if you have the flu
Symptoms of the flu (influenza) include:
Sudden onset
Typically starts with a headache, chills and cough, followed rapidly by fever, loss of appetite, muscle aches and fatigue, runny nose, sneezing, watery eyes and throat irritation
Nausea, vomiting and diarrhoea may also occur (especially in children)
Fever may not be prominent in children under 5 years of age and adults 65 years of age and older
Complications that can arise from the flu
Pneumonia
(secondary
and bacterial)
- Respiratory failure |
Myocarditis |
Pericarditis |
Death from overwhelming sepsis can progress rapidly |
Myositis |
Reye's syndrome |
Otitis media |
Exacerbates underlying medical conditions e.g. pulmonary, cardiac or metabolic disease |
Encephalopathy |
Bronchitis |
Acute Myocardial Infarction (AMI) |
The flu vs COVID-19
Both the flu (influenza) and COVID 19:
Are transmitted by respiratory droplets from an infected person
Can cause fever, cough, runny or stuffy nose, sore throat, muscle aches, shortness of breath, fatigue
As symptoms for both are very similar, taking an ART (antigen rapid test) or PCR (polymerase chain reaction) test will tell you if you have contracted COVID-19 instead of the flu.
Symptoms |
Begin 1-4 days after exposure |
Begin 1-14 days after exposure |
|---|
Causes |
Influenza virus
(there are many strains) |
SARS-CoV-2 virus |
|---|
Complications |
Less likely to occur because of immunity built up over time |
Severe respiratory complications may come on extremely quickly |
|---|
Prevention Tips |
Get the flu vaccine Wash your hands frequently with soap and water Wear a face mask in crowded, indoor public spaces Practice safe distancing as best as possible in indoor public spaces Avoid touching your eyes, nose and mouth If you are sick, stay at home When sneezing or coughing, cover your nose and mouth with the inside of your elbow or a tissue When sick, avoid sharing food, dishes, glasses, towels and other household items
|
COVID-19 vaccine protects you against severe disease and minimises risk of transmission Wash your hands frequently with soap and water Wear a face mask in crowded, indoor public spaces Practice safe distancing as best as possible in indoor public spaces Avoid touching your eyes, nose and mouth If you are sick, stay at home When sneezing or coughing, cover your nose and mouth with the inside of your elbow or a tissue When sick, avoid sharing food, dishes, glasses, towels and other household items
|
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* Based on the 2015 Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) influenza research sero-survey in New Zealand that showed 80 per cent of those infected with influenza were asymptomatic carriers.
Ref: L20
Check out other related articles:
How to Protect Yourself and Loved Ones from COVID-19
Flu and the Common Cold: What You Need to Know
6 Easy Ways to Prevent the Cold and Flu
COVID-19 Vaccine Myths Busted!
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