Highly pathogenic A(H5N1) bird flu first appeared in southern China in 1996. The next year, large outbreaks in poultry led to 18 human infections.
The virus was not controlled and re-emerged in 2003, spreading widely across Asia. Over time, A(H5N1) reached Africa, Europe, and the Middle East.
Since 2020, 91 human cases of highly pathogenic bird flu have been reported worldwide. Here’s what to know about the outbreaks in affected locations.
A California duck farm has tested positive for H5N9, marking the first confirmed case in the U.S. The outbreak began on November 23, 2024, after a rise in duck deaths.
H5N9 is a low-pathogenic virus that usually causes mild symptoms in birds. Officials have not reported any human infections linked to the outbreak. The virus has been detected in farmers in other countries, but no cases have been confirmed in the U.S.
A tuberculosis (TB) outbreak has become the largest ever recorded in U.S. history. Since early 2024, officials have reported 67 active TB cases and 79 latent cases.
The World Health Organization recorded 8.2 million global TB cases in 2023. This is the highest number since WHO began tracking TB in 1995. Last year, tuberculosis once again became the world’s deadliest disease.
A new meta-analysis in the British Journal of Sports Medicine found that higher physical activity decreases disease risk and early death. Researchers analyzed data from over 30 million people across 94 large studies. The study focused on non-occupational physical activity, including exercise and walking.
A new study in the Journal of Infection links salmonella outbreaks to climate change. Warmer temperatures, higher humidity, and lower rainfall increase infection risks.
Researchers examined 14 weather factors to estimate salmonella rates. They used case reports from 2000 to 2016 and weather data from England, Wales, and the Netherlands.
The study’s methods could apply to other countries. Salmonella cases likely follow similar weather patterns worldwide.
