Summary:

• There is much uncertainty in predicting the next major incidence of influenza A
• The source of recent clinical cases of A/H5N1 in Cambodia are unknown
• A/H5N1 is highly virulent in farmed poultry and can crossover to infect humans
• Human-to-human transmission would pose a significant public health threat
• Regional pandemic preparedness in Southeast Asia is required to mitigate this risk

Conclusion: Highly pathogenic avian influenza A (HPAI H5N1), more commonly known as bird flu – is, as the name suggests – primarily a disease that affects birds, yet it can also infect mammals, including humans. HPAI is a persistent public health threat as a leading cause of severe respiratory disease. While the source of infection of the A/H5N1 isolate that caused the death of a child in Cambodia may never be determined unequivocally, this emergency event should sound a warning of what may be to come. With the virtue of hindsight, in all but a handful of countries the real time surveillance and early detection system in place at the start of the COVID-19 pandemic for control of community transmission was grossly inadequate and need of major overhaul. Striking a positive note, those hard-learnt lessons are now helping to ensure better outbreak preparedness and threat mitigation for a virulent strain of bird flu should it spread to, and between, humans.