Now that COVID-19 has receded thanks to highly effective vaccines, the three infectious diseases of greatest concern to health officials are malaria (a parasite), HIV (a virus), and tuberculosis (a bacterium), which together kill about 2 million people annually, Connor Meehan writes in his article for The Conversation magazine.
In addition, Meehan notes that there are lists of priority pathogens, especially those that have developed resistance to commonly used drugs, particularly antibiotics and antivirals.
Scientists must simultaneously monitor current threats while staying vigilant for the next potential problem. While any pathogen could pose a risk, certain groups, such as influenza viruses, are more likely to cause rapid outbreaks.
According to the article’s author, one of the influenza viruses currently causing serious concern is on the verge of becoming a major problem by 2025. This virus, the H5N1 influenza A virus—sometimes called ‘bird flu’—is common in both wild and domestic birds. It has also recently infected dairy cattle in several U.S. states and has been detected in horses in Mongolia.
When cases of bird flu or swine flu begin to rise, there is always concern that the virus could spread to humans through contact with infected livestock or by consuming raw milk.
Compared to the previous two years, when only two cases of the disease were reported in the United States, this represents a significant increase. With a 30% fatality rate among human infections, bird flu is rapidly becoming a top priority for health officials.
Fortunately, H5N1 avian flu does not appear to spread from person to person, significantly reducing the likelihood of a human pandemic. Influenza viruses must bind to molecular structures called sialic acid receptors on the surface of cells to enter and begin replication.
Influenza viruses well-adapted to humans recognize these receptors, allowing them to enter our cells easily and facilitating their spread between humans. In its current form, H5N1 cannot easily spread among humans.
Recent research has shown that a single mutation in the flu genome could enable H5N1 to spread from person to person, potentially causing a pandemic.
If this strain of bird flu mutates and starts spreading from person to person, governments will need to act quickly to contain its spread.
For example, the UK has purchased 5 million doses of the H5 vaccine, which protects against bird flu, in preparation for the potential emergence of the threat in 2025.
Even without the potential for spreading to humans, avian flu is expected to have a greater impact on animal health in 2025. This will not only have serious implications for animal welfare, but could also disrupt the food supply and lead to economic consequences, Meehan stressed.
