“The cholera strain in Haiti is evolving, researchers reported Thursday, a sign that it may be taking deeper root in the nation less than two years after it appeared and killed thousands of people,” the Associated Press/USA Today reports. “The study released by the U.S. Centers for Disease Control and Prevention indicates that the bacterium is changing as survivors acquire at least some immunity to the original bug, which apparently was imported from Nepal,” the news service writes (Daniel, 5/5). “The evolution of the cholera strain was expected and typical of the disease, according to the CDC,” CBS Miami notes (5/4).

“‘This suggests that the ongoing epidemic in Haiti might be entering its next phase, since we see these shifts where cholera is endemic,’ said Dr. Edward T. Ryan, an infectious disease specialist with Massachusetts General Hospital who was not involved with the study,” the AP writes, adding, “The change also means it could be easier for Haitians to fall ill a second time to the new cholera version because they don’t have full immunity to it if they don’t take precautions such as washing their hands or chlorinating water.” The news service notes that “[i]n an effort to stem the spread of the disease, the Boston-based Partners in Health and its partner, the GHESKIO Center, have launched a campaign to vaccinate 100,000 Haitians, or one percent of the national population, in a neighborhood in Port-au-Prince and in a rural area north of the capital” (5/5).