Influenza occurs year-round, but influenza A cases are sharply increasing in late autumn and early winter. Doctor Le Anh Trong, from the Pediatrics Department at Tam Anh General Hospital Hanoi, stated that the number of children seeking examination and treatment for influenza A at the hospital has risen sharply. In the first half of November alone, hospitalizations due to influenza A increased by almost 30% compared to the previous month. Humid environments and dry weather create favorable conditions for the influenza virus to develop and spread rapidly in the community.

Influenza A is transmitted via the respiratory tract, placing children at high risk due to their underdeveloped immune systems and sensitive respiratory systems, which struggle to clear the virus. When it enters the body, the influenza A virus can weaken the immune system, leading to bacterial superinfections such as *streptococcus pneumoniae*, *staphylococcus aureus*, and *haemophilus influenzae*. The virus damages the respiratory epithelial lining of children, causing symptoms like persistent high fever, runny nose, and an increasing cough, along with extreme fatigue and irritability.

A doctor examines a child with bronchiolitis, a complication of influenza A. *Photo: Tam Anh General Hospital*

Several dangerous complications can arise when children contract influenza A:

Pneumonia and respiratory failure

Primary influenza pneumonia manifests with persistent symptoms such as cough, sore throat, headache, muscle aches, and discomfort for 3 to 5 days. This complication commonly affects children under 5 years old, those with other chronic conditions, or those with compromised immune systems.

Otitis media

This is a common complication, especially in premature infants or children with other congenital conditions.

Encephalitis, meningitis

Influenza A encephalitis is common in children under 2 years old, severely affecting the central nervous system. Some children experience an excessive inflammatory response, leading to neurological damage, seizures, and coma. The disease progresses rapidly, often appearing 2 to 3 days after a high fever of 39-40 degrees Celsius. If fever symptoms are not properly managed, children can quickly develop neurological infections, showing seizures, coma, and vomiting.

Myocarditis

The influenza virus can directly attack the heart muscle, causing arrhythmias, heart failure, or sudden cardiac arrest. Viruses, particularly the influenza virus, primarily cause myocarditis, an inflammation of all or part of the heart muscle. Doctor Trong noted that post-influenza A myocarditis in children causes symptoms such as chest pain, shortness of breath, rapid heartbeat, fatigue, or pale lips and skin. Some children initially experience fever, cough, fatigue, abdominal pain, nausea, vomiting, and diarrhea.

Parents should take their children to a medical facility immediately if they show these signs for timely diagnosis and treatment. Myocarditis can lead to dangerous complications like heart failure or cardiac arrest.

Septic shock

When the virus spreads widely, it causes systemic inflammation, leading to coagulation disorders and multi-organ failure. Septic shock is a dangerous complication of severe influenza A. Warning signs include persistent high fever, rapid breathing, lethargy, bluish lips or extremities, and continuous vomiting.

To prevent complications in children with influenza A, parents need to ensure their children receive full vaccinations, maintain personal hygiene and a clean living environment, and wash hands thoroughly before preparing food. Children should wear masks when going out and avoid contact with people showing signs of illness. If children show signs of influenza, parents should take them to a medical facility for examination. Do not self-administer medication or unverified folk remedies, as these can harm the child's health.

Hang Tran