Federal records obtained by the Star revealed 138 incidents of lost fentanyl from Canadian hospitals at a rate of about...

U.S. measles cases have surged to 704. Outbreaks reveal pockets of vulnerability where too many unvaccinated people are...

Each year from 2010 to 2017, 21 million children did not get vaccinated against measles, according to UNICEF.

A Zika outbreak in a Brazilian slum suggests that the timing of dengue infections may matter for protection against Zika...