Patients testing positive again for COVID-19, baffling experts

Health experts remain puzzled over why COVID-19 patients who have recovered from the disease are again testing positive for novel coronavirus infections. Such cases are rare. But they do raise questions about possible limits on testing accuracy and highlight the need for more studies on the virus that has spread around the world. At least 35 people in Japan, ranging in age from their 20s to their 90s, have tested positive twice for the coronavirus, according to reports in The Asahi Shimbun and interviews with local government officials. One was a woman in her 20s living in Nagoya who had developed a cough and fever of 38.5...