Tsetse flies, vectors of trypanosomiasis, thrive in the tropical climes of sub-Saharan Africa—killing thousands annually. But Nigerian scientist Emmanuel Balogun, a biochemist at Ahmadu Bello University Zaria, is determined to thwart the parasites that cause sleeping…

Scientists are sounding the alarm about 2 little-understood diseases—1 that claims nearly 90,000 lives a year—and calling for more research into treatment and prevention. Zika, a mosquito-borne virus, is responsible for a major outbreak in Brazil, with the potential for…