Communicable disease threats report: Influenza A(H5N1) – Multi-country (World) – Monitoring human cases
2. Influenza A(H5N1) – Multi-country (World) – Monitoring human cases Update:
On 3 August 2024, the Ministry of Health of Cambodia reported a human case of A(H5N1) avian influenza virus infection in an adolescent girl from Chantrea district, Svay Rieng province (Ministry of Health in Cambodia). The case presented to hospital with fever, cough, sore throat and difficulty breathing and was admitted to an intensive care unit. The patient remains in a serious condition. The case was laboratory confirmed by the National Institute of Public Health and the Pasteur Institute in Cambodia on 3 August 2024. Virus clade has not yet been announced. According to an investigation by local authorities, four days prior to the onset of disease the case had exposure, both at their own house and a neighbour's house, to nine dead chickens, which were later cooked. Since 2003, Cambodia has reported 71 human H5N1 cases with 42 fatalities, highlighting the ongoing zoonotic transmission risk in the region.
National and local health authorities, together with the Ministry of Agriculture, Forestry and Fisheries and the Ministry of Environment, are continuing to search for sources of transmission in both animals and humans, and are conducting contact tracing, administering Tamiflu prophylaxis to close contacts, and emphasising the importance of proper handling and cooking of poultry to prevent further infections.
Since 2003, and as of 5 August 2024, there have been 907 human cases worldwide*, including 463 deaths (CFR: 51%), with avian influenza A(H5N1) infection reported in 24 countries (Australia (exposure occurred in India), Azerbaijan, Bangladesh, Cambodia, Canada, Chile, China, Djibouti, Ecuador, Egypt, Indonesia, India, Iraq, Laos, Myanmar, Nepal, Nigeria, Pakistan, Spain, Thailand, Türkiye, Vietnam, United Kingdom and the United States).
To date, no sustained human-to-human transmission has been detected. In 2024, 24 cases, including two deaths, have been reported in four countries: Cambodia (nine cases, one death), the United States (13 cases), Vietnam (two cases, one death), and Australia (one case). *Note: this includes six detections due to suspected environmental contamination and no evidence of infection that were reported in 2022 by Spain (two detections) and the United States (1), as well as in 2023 by the United Kingdom (3).
