A deadly and highly contagious disease among birds has started to spread to humans; should we be worried?
Did you know that H5N1, a single strain of bird flu, has shown a 50% mortality rate in humans? Despite being rare, human infection with bird flu can be deadly, and scientists worry about its potential to cause a pandemic (8).
Bird flu is a disease that naturally spreads among wild and domesticated birds; that’s why it was so surprising when 18 people in Hong Kong were reported having the disease in 1997, and 6 died as a result. Scientists generally fear the disease due to its high mortality rate of almost 100% in bird species. If the disease spreads among humans, the risks could be equally deadly and widespread (3).
Usually, it takes from 10 to 40 years for an animal-related virus to spread to humans and cause a pandemic, and 15 years have passed since the last swine flu outbreak. This trend suggests that the question isn’t if the next pandemic will occur, but when. Scientists are researching this potential threat and working to minimize its chances of becoming the next human pandemic (7).
Timeline of when Bird Flu Outbreaks Occurred among Birds (8)
As of December 18th, 2024, 61 cases of H5N1 had been reported that year, bringing the total number of cases since 2003 to 954 (4). Of these, around 464 deaths have been reported—a 50% mortality rate (6).
Currently, there are no reports of the disease spreading among humans, except rarely after close contact (2). However, this reality can change. The concern among scientists is that seasonal influenza could exchange genetic material with the H5N1 disease, potentially creating a virus able to infect and spread among humans. While unlikely to occur, this phenomenon was the exact cause of the past 3 pandemics, and we therefore must be cautious of the disease (3).
Stat Sheet Showing Numbers of H5N1 Cases and Deaths globally (7)
Humans must be more careful around birds to ensure that we aren’t going to get infected. Unprotected exposure to infected animals through inhalation or contact poses great risk of infection. For this reason, farmers and poultry workers are advised to wear protective gear such as face masks or gloves (1).
The World Health Organization (WHO) has been closely monitoring flu outbreaks and taking various measures to prevent human infection; these measures involve mass culling, or slaughtering, operations of infected birds (2). The WHO will continue these efforts until the virus no longer poses a threat to the safety of humans and other animals.
Since bird flu rarely infects humans and hasn’t been reported to spread between them, a pandemic is currently unlikely. However, without caution, it could still emerge. We need to ensure that we are tracking and staying away from infected birds and other animals, while also keeping workers safe through spreading awareness. If everyone works together, we can make a monumental impact in preventing the virus from progressing into the next pandemic.
Bibliography
- Occupational Safety and Health Administration. (July 27, 2020), Avian Influenza, Retrieved from https://www.osha.gov/avian-flu#:~:text=Commonly%20known%20as%20avian%20flu,birds%20like%20chickens%20and%20turkeys.
- Niti Mittal and Bikash Medhi. (July 7, 2007), The Bird Flu: A New Emerging Pandemic Threat and Its Pharmacological Intervention, Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC3068632/#:~:text=In%20fact%2C%20the%20spread%20of,viral%20vaccination%20and%20health%20monitoring.
- Morgan Coulson. (January 14, 2025), Bird Flu is Raising Red Flags Among Health Officials, Retrieved from https://publichealth.jhu.edu/2025/bird-flu-is-raising-red-flags-among-health-officials
- Micheala Simoneau, Sophia Hirshfield, and Maclane Speer. (December 19, 2024), The United States Needs to Step Up it’s Response to Bird Flu, Retrieved from https://features.csis.org/US-bird-flu-response/
- Jayne Roberts. (December 20, 2024), What is bird flu, and should you be worried? Retrieved from https://news.uga.edu/should-you-be-worried-about-bird-flu/
- Anna Fleck. (December 16, 2024), Where Bird Flu has jumped to humans, Retrieved from https://www.statista.com/chart/33683/cumulative-number-of-confirmed-h5n1-cases-worldwide/
- Dr Colin J Carlson. (January 16/2025), The bird flu threat to humans in the United States, Retrieved from https://ysph.yale.edu/news-article/the-bird-flu-threat-to-humans-in-the-united-states/
- Helen Branswell. (December 2, 2024), Scientists confront a mystery: Why have US bird influenza cases been so mild, Retrieved from https://www.statnews.com/2024/12/02/bird-flu-h5n1-mild-cases-mystery/#:~:text=For%20more%20than%20two%20decades,in%20line%20with%20Ebola%20viruses.
- Miryam Naddaf. (October 18, 2023), How the current bird flu strain evolved to be so deadly, Retrieved from https://www.nature.com/articles/d41586-023-03256-3