Rift Valley fever mainly affects farm animals. But the virus can also infect humans, and South Africa has been experiencing an outbreak. The National Institute for Communicable Diseases reported two hundred twenty-five confirmed human cases as of July second. Twenty-five of the people died.

South Africa launched an expanded program to watch for public health threats during the World Cup. Health officials said last week that there were no cases of Rift Valley fever in tourists. The majority of farms affected by the outbreak are outside areas generally visited by travelers.