The Australian melon producer, which the WHO did not name, recalled the fruit on 27 February. “It is believed that the cause of the outbreak was a combination of environmental conditions and weather contaminating the surface of the fruit, with low levels of the bacteria persisting after the washing process,” the WHO said.
Listeriosis can come in a mild form that causes diarrhoea and fever in healthy people within a few days but he Listeria monocytogenes bacterium has a potentially long incubation period, usually one or two weeks but possibly up to 90 days, so more cases may be reported. it also has a severe form that can cause septicemia and meningitis among more high-risk people, such as pregnant women, infants, old people, and people having treatment for cancer, Aids or organ transplants. The severe form has a 20-30% mortality rate. The rockmelons, or cantaloupes, were sent to Hong Kong, Japan, Kuwait, Malaysia, Oman, Qatar, Singapore, the United Arab Emirates and Bahrain, and may also have gone to the Seychelles, a WHO statement said. Between Jan 17 and April 6, Australia itself reported 19 confirmed and one probable case of listeriosis. Seven died.