The Guangdong Provincial Center for Disease Control and Prevention announced that between March 3 and March 9, 2025, one influenza outbreak was reported in the province, occurring in a primary school and caused by the H1N1 influenza A virus.
(Photo: Nanfang Plus)
Key Epidemiological Data: Influenza-Like Illness (ILI) Surveillance
During the 10th week of 2025 (March 3-9), sentinel hospitals reported that ILI cases accounted for 5.87% of total outpatient and emergency department visits, a slight decrease from the previous week's 5.90% but aligning with the baseline level (5.89%).
Virological Surveillance
The positivity rate for influenza viruses in tested ILI specimens was 17.49%, marking a continuous decline from 23.13% the prior week but remaining above the baseline (12.44%).
Among positive samples, the H1N1 influenza A virus dominated, accounting for 94.15% of detections.
Outbreak Reporting
One influenza outbreak was reported this week, occurring in a primary school and attributed to the H1N1 strain. Kang Min, Director of the Infectious Disease Prevention and Control Institute at GDCDC, emphasized, "While Guangdong's flu activity continues to decline and is expected to return to non-epidemic levels soon, high-risk settings like schools and childcare facilities remain vulnerable to outbreak clusters.”
Recommendations:
For educational institutions: implement daily health checks, enhance ventilation, maintain hygiene protocols, and promote handwashing and respiratory etiquette.
For the public: practice frequent handwashing, use masks in crowded or poorly ventilated spaces, and stay vigilant against flu symptoms.
Understanding H1N1 Influenza:
H1N1, a subtype of influenza A viruses categorized by surface proteins hemagglutinin (HA) and neuraminidase (NA), is a major driver of seasonal flu epidemics. Symptoms include:
Fever: often high-grade (39-40℃).
Systemic symptoms: chills, headache, muscle/joint pain, fatigue, and appetite loss.
Respiratory symptoms: sore throat, cough, and occasionally nasal congestion or gastrointestinal issues.
Critical Distinction: Flu ≠ Common Cold
Unlike mild colds, influenza can lead to severe complications, including pneumonia, multi-organ failure, and death. The World Health Organization estimates seasonal flu causes 3-5 million severe cases and 290,000-650,000 respiratory deaths globally each year.
Transmission: Primarily via respiratory droplets; indirect contact (e.g., touching contaminated surfaces) is also possible.
Prevention: Vaccination remains the most effective measure to reduce severe outcomes. High-risk groups, including children, the elderly, and immunocompromised individuals, are urged to prioritize immunization.
Features | Influenza | Common Cold |
Pathogen | Influenza virus | Rhinovirus, Parainfluenza virus, Common coronavirus, etc. |
Contagiousness | High | Low |
Seasonality | Distinct seasonal pattern | No clear seasonal pattern |
Fever Degree | High fever common (39~40℃) with chills | No fever or mild-moderate fever; chills rare |
Systemic Symptoms | Pronounced (fatigue, muscle aches, etc.) | Mild or absent; primarily upper respiratory symptoms |
Upper Respiratory Symptoms | Headache, cough, sore throat | Runny nose, sneezing, nasal congestion, sore throat |
Duration | Typically 7-10 days | Typically 3-5 days |
Health authorities remind the public to avoid self-medication and seek prompt medical attention if flu symptoms persist. Enhanced surveillance and proactive prevention measures will be critical in mitigating future outbreaks.
Author | Jiang Chang
Info Source | China CDC
Editor | Wei Shen, James, Shen He
