H5N1 Bird Flu Outbreak Remains Stable Worldwide with Low Human Risk CDC and WHO Report

Bird Flu Bulletin: Daily H5N1 Update Friday, September 5, 2025 This is Bird Flu Bulletin: Daily H5N1 Update, your trusted source for concise, fact-based updates on the H5N1 avian influenza outbreak. Today is Friday, September 5, 2025. Top Stories First, data from the World Health Organization confirm Cambodia remains a focus for human H5N1 infection. No new human cases have been reported globally in the last 24 hours, with Cambodia’s Ministry of Health most recently documenting a case on August 5. Of the 11 human H5N1 cases in Cambodia this year, seven appeared in June, describing an unusual increase for a single month. Since the virus re-emerged in humans in February 2023, Cambodia has now recorded 27 cases and 12 fatalities. WHO continues to stress that the current risk to the general population remains low, but rates exposure risk for farm workers as low to moderate, depending on preventive measures. Second, animal outbreaks remain persistent but stable. According to the Food and Agriculture Organization, highly pathogenic avian influenza continues to be reported in poultry and wild birds. In the last 48 hours, Portugal and South Africa have each recorded new H5N1 outbreaks in poultry, while Argentina has recently documented cases in wild birds. The FAO emphasizes the ongoing need for strong biosecurity on farms and continued monitoring of wild bird populations. Third, an important health advisory remains in effect in the United States. The Centers for Disease Control and Prevention updates that detections of H5N1 in dairy cattle continue to be monitored, with 1,077 herds in 17 states affected since last year. The CDC states that over the past 30 days, detections have slowed, with only three new outbreaks in one state. The CDC also reaffirms there is no evidence of sustained human-to-human transmission and that seroprevalence studies among farm and dairy workers indicate low rates of infection and mild symptoms in rare human cases. Case Numbers Compared to yesterday, no new human H5N1 cases have been confirmed worldwide. The global count stands unchanged, with 986 human cases and 49 deaths reported to WHO since 2003, including the 27 cases in Cambodia post-2023. Animal outbreaks have continued at a steady pace, with incremental increases in poultry and wild birds but no unusual surges. Health Authority Guidance The World Health Organization has reiterated updated case definitions for confirmed human H5 cases and urges all countries to immediately report laboratory-confirmed infections. WHO advises that those with occupational exposure to poultry or potentially infected environments should maintain strict protective measures and report any flu-like symptoms to health authorities promptly. Expert Voice For brief insight, we reached Dr. Lina Chen, virologist at the Pan American Health Organization, who told us: “Continued animal outbreaks show H5N1 is entrenched in wildlife reservoirs. While human risk remains low, vigilance is essen This content was created in partnership and with the help of Artificial Intelligence AI.