Measles Was Gone, But It Came Back

Measles was eliminated from the United States in 2000. It could have stayed gone, but it didn’t. As of April 19, 626 cases had been reported to the CDC so far in 2019 in multiple states: Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Massachusetts, Michigan, Missouri, Nevada, New Hampshire, New Jersey, New

Do Helmets Prevent Head Injuries?

A cycling enthusiast asked me about helmets. It seems compellingly obvious to me that a head impacting the pavement without a helmet is likely to sustain more damage than a head protected by a helmet. He challenged that, citing a BMJ article by Ben Goldacre that questioned whether the evidence showed that helmets do any good. He said I

Worms, Germs, and Dirt: What Can They Teach Us About Allergies and Autoimmune Diseases?

Humans evolved in an environment where they were exposed to animals, dirt, and a variety of pathogens and parasites. Our immune systems evolved to cope with that environment. Now most of us live in a different environment, with safe drinking water, flush toilets, food inspection, immunizations, and public sanitation. This means that we are far