Vietnam has contained the fatal bird flu cases that raged in the late 2000s, but it is still struggling with new cases of the virulent disease. Here, a poultry trader loads live chickens onto his motorbike on March 16 at a market outside Hanoi.
Hoang Dinh Ham/AFP/Getty Images
Timothy Ray Brown, widely known in research circles as the Berlin patient, was cured of his HIV infection by bone marrow transplants. Now scientists are trying to make sense of the traces of HIV they've found in some cells of his body.
A nurse in Washington administers the whooping cough vaccine to a child in May. In response to the epidemic, more than 82,000 adults have also received the vaccine this year.
Ted S. Warren/AP
Gao Weiwei, a doctor of the Beijing Chest Hospital which specializes in the treatment of tuberculosis, talks to a patient suspected to have tuberculosis at the hospital in Tongzhou, near Beijing, March 27, 2009.
Ng Han Guan/AP
The Anopheles stephensi mosquito transmits the malarial parasite while dining on human blood. You can find this type of mosquito in Afghanistan, China, India, Thailand and the Middle East.