Oct 10, 2008 (CIDRAP News) The World Health Organization (WHO) today said a mysterious febrile disease that bears some resemblance to a viral hemorrhagic fever (VHF) has killed three people in Johannesburg, South Africa.
The WHO said the victims so far have tested negative for several VHFs and other infectious diseases, and no new cases have emerged since the latest death on Oct 5.
The first victim was a woman from Zambia who fell ill while on a safari and died in a Johannesburg hospital on Sep 14, the WHO said. Subsequently, a paramedic who cared for the woman during her evacuation got sick on Sep 27 and died Oct 2, and a nurse who cared for the first patient in South Africa died Oct 5.
A fourth case was linked to the three reported by the WHO, but that patient was found to have "an alternative diagnosis," which was not named, South Africa's National Institute for Communicable Diseases (NICD) said in a bulletin. The statement gave no details about that patient.
"Clinical features common to the three patients initially include fever, headache, diarrhoea, and myalgia developing into rash and hepatic dysfunction, followed by rapid deterioration and death," the WHO said. "Bleeding was not a marked clinical feature."
The index patient had close contact with horses and a history of a possible tick bite, and was given a diagnosis of "tick bite fever," the NICD said. But she died shortly after arriving in South Africa, and no samples were available for testing, the agency said.
So far, multiple tests on the other patients have been negative for Crimean-Congo hemorrhagic fever and Ebola, Marburg, Lassa, and Rift Valley fever viruses, according to the NICD. Serologic tests have excluded hantaviruses. "The final results for viral culture in animal and cell cultures are pending," the statement said.
The negative findings so far could be explained by the fact that samples were taken late in the illness (day 10)or by the presence of virus variants not detectable with current molecular and serologic tests, the NICD said.
With no other cases identified so far, the NICD said, "It seems likely that this is an isolated case with secondary transmission in the nosocomial setting. Given the high mortality, nosocomial transmission, and clinical presentation, a viral haemorrhagic fever remains possible."
The WHO said epidemiologists from the agency's African Regional Office have gone to South Africa and Zambia to support the investigations.
There is no indication of a need for restrictions on travel to or from South Africa or Zambia, and no special measures are needed for passengers arriving from the two countries, the WHO said.
Oct 10 WHO statement