“As you can see, my boss and I are the only two health workers serving at this facility,” a nurse named Martha told us at a local dispensary in Tanzania’s remote Geita region. “I normally take charge of the facility in his absence,” she said. “It has always been a challenge reaching out to him for assistance in such moments. Due to lack of airtime credits, sometimes I just beep his number and wait for him to call back.” We talked with over 1,000...