Measles cases rise in U.S. after declaration of elimination

Emerging infectious diseases are infections that either appear for the first time or return after being absent. These diseases can fall into two categories: newly emerging and reemerging. Newly emerging diseases are previously unknown or rapidly spreading infections. Reemerging diseases refer to infections that have come back, sometimes in new forms. Common examples include avian flu, measles, tuberculosis, polio, and mpox. From March to October 2024, 27 cases of avian influenza A were reported in the United States. All affected individuals received treatment and recovered. There was a notable case where H5N1, a type of avian flu, was transmitted from cows to humans. While the public health risk is low, those working with infected animals should take safety precautions. H5N1 from cows generally causes mild symptoms such as conjunctivitis and low-grade fever. It differs from other H5N1 strains that can be severe. The main risk to people comes from consuming raw milk, as H5N1 from cows has limited ability to spread through the air. Measles outbreaks are occurring in the United States despite its elimination in 2000. As of March 2025, there are 222 reported cases. The World Health Organization recommends that children receive their first measles vaccine between 9-18 months and a second dose shortly after to ensure immunity. In 2023, around 10.8 million people worldwide were sick with tuberculosis (TB). Despite an increase in cases in the U.S., the overall risk remains low. TB is treatable, and different dosages are used for children and adults. It's essential to consider the timing of treatment, especially for pregnant women. A case of paralytic polio was reported in New York in 2022, marking the first U.S. case since 2013. This is concerning as it could indicate wider community spread. Most polio infections show no symptoms, but the unvaccinated are at the highest risk. Lastly, a global mpox outbreak began in May 2022. Symptoms often include skin lesions, fever, and fatigue, with skin lesions appearing mainly in the anogenital area.