Yellow fever outbreak in Brazil worries U.S. officials

Lena H. Sun – March 8, 2017

Top infectious disease experts are warning about a rapidly spreading outbreak of deadly yellow fever in Brazil that could hit parts of the United States. The danger would be most acute if the virus starts spreading by the same mosquito that transmits Zika.

The outbreak in Brazil has been underway since December, mostly in rural areas in the southeastern part of the country. It’s taking place primarily in jungle areas, where forest-dwelling mosquitoes are spreading the virus mainly to monkeys. But an increasing number of people also have been infected, making it Brazil’s worst yellow fever outbreak among humans in decades. There have been at least 326 confirmed cases, including 220 deaths, with hundreds of additional cases under investigation, according to the Pan American Health Organization (PAHO).

Writing Wednesday in the New England Journal of Medicine, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said experts are concerned because the number of yellow fever cases is much higher than what’s reported in a typical year in this part of Brazil.