The Department of Health's Centre for Health Protection announced today (28th) a severe case involving a 2-year-old girl infected with Influenza A. The patient passed away last night (27th) due to complications, marking the third unfortunate death of a child from influenza this year. Hong Kong paediatric specialist Dr. Hon Kam Lun previously told Sing Tao Headline that many parents believe children can just "sleep it off" when they show flu symptoms like fever and cough, but this overlooks potentially fatal risks. He therefore recommends parents get their children vaccinated against influenza.
Dr. Hong Kam-lun stated that the primary route of influenza transmission is through respiratory droplets. "Many parents think children can just 'sleep off' symptoms like fever and cough, but this could potentially lead to fatal complications," Hong warned. He reminded that once complications like myocarditis (inflammation of the heart muscle) occur, it can be particularly difficult to diagnose in young children. By the time it's confirmed, the golden window for treatment might have been missed. Therefore, it's best to seek medical attention immediately when a child develops symptoms like fever, fatigue, or loss of appetite. It's also advisable to keep rapid influenza test kits at home, as they have relatively high accuracy and can help detect infection early.
Flu Symptoms & Differences Between Influenza A and B
Regarding the differences between Influenza A and B, Hong analysed that their symptoms are quite similar; the main difference lies in the severity of the illness. Influenza A typically spreads faster, is more active, has a more sudden and acute onset, and the condition is often more severe, potentially involving high fever. On the other hand, Influenza B generally spreads slightly slower, and its symptoms and severity are milder than Influenza A. Among the flu patients he sees, the number of Influenza A cases is relatively higher.
Many people assume that only those with chronic illnesses are at high risk for severe flu. However, he explained that even healthy individuals can succumb to the flu. "Some children have immune systems that are too strong, even overreacting, which can trigger fatal complications like pneumonia, myocarditis, or encephalitis."
What Types of Flu Vaccines Are There?
Hong reminded that although the fatality rate of influenza is not high, over 20 percent of severe flu cases can lead to bacterial infections, making the rate of severe illness relatively high. While getting a flu shot doesn't guarantee 100 percent prevention or completely eliminate symptoms, it provides protective power and reduces severe symptoms. Therefore, he recommends parents vaccinate their children.
Flu vaccines generally fall into two categories: injectable and nasal spray. Hong mentioned that the nasal spray vaccine is often used for younger children, though its effectiveness is slightly weaker. Side effects of the injection are mostly redness, swelling, and pain at the injection site, or fever; a very small number of people might experience more severe allergic reactions like hives. The nasal spray vaccine can cause local irritation in the nasal passages, potentially leading to side effects like tracheal discomfort, though this is less common.
Regarding treatment, there are currently two main medications available in Hong Kong for treating influenza:
- Oseltamivir (commonly known as Tamiflu): Can be taken once or twice daily for 5 days.
- Baloxavir marboxil: Can be taken as a single dose.
Influenza A / Influenza B – Which Has the Highest Mortality Rate?
According to Department of Health information, seasonal influenza is an acute respiratory illness caused by influenza viruses. There are three known types of seasonal influenza viruses that infect humans: A, B, and C. Types A and B account for the majority of infections, and historically, influenza outbreaks are often associated with Type A viruses.
- How to Identify Influenza A?
- Common Symptoms: Fever, chills, headache, cough, sore throat, runny nose.
- High-Risk Groups: The elderly, young children, or immunocompromised individuals may develop complications like bronchitis, pneumonia, or even encephalitis, myocarditis, or pericarditis after infection, which can be fatal in the most severe cases.
- Severity/Mortality: The condition is generally more severe, with a higher mortality rate.
- Infectivity: Higher transmission and pathogenicity. Currently the main influenza virus type responsible for pandemics. The emergence of a new Influenza A virus can potentially lead to a new wave of flu outbreaks.
- How to Identify Influenza B?
- Common Symptoms: Similar to Influenza A.
- Infectivity/Severity/Mortality: The illness is generally milder than Influenza A, with a lower mortality rate. Its rate of evolution is 2-3 times slower than the Influenza A virus.
The Department of Health states that the usual flu season in Hong Kong runs from January to March and, to a lesser extent, from July to August. Most people recover from flu on their own. Those with mild symptoms should get plenty of rest and drink plenty of water. If flu symptoms develop, you should not go to work or school. If symptoms persist or worsen, seek medical attention promptly.
