Grand Canyon National Park said a concessions employee has been diagnosed with hantavirus pulmonary syndrome and two visitors were exposed to rabies after handling a bat that later tested positive, marking two separate public-health incidents at the park this month. The employee is believed to have contracted the rodent-borne virus through contact with contaminated droppings; the visitors began post-exposure prophylaxis immediately after the bat was confirmed rabid, according to park officials. No further illnesses have been reported. Park management, working with the National Park Service Office of Public Health and the Arizona Department of Health Services, has increased signage, stepped up rodent-control efforts and urged travelers to avoid touching wildlife, secure food and promptly report sick or dead animals. Officials said the park remains open and that the risk to the general public is low if standard precautions are followed.