Nosocomial Outbreak of Novel Arenavirus Infection, Southern Africa

A nosocomial outbreak of disease involving 5 patients, 4 of whom died, occurred in South Africa during September-October 2008.The first patient had been transferred from Zambia to South Africa for medical management.Three cases involved secondary spread of infection from the first patient, and 1 was a tertiary infection.A novel arenavirus was identified.The source of the first patient's infection remains undetermined.A renaviruses associated with rodents are known to cause fatal hemorrhagic fevers in humans in South America and West Africa.We describe a nosocomial outbreak of infection with a novel arenavirus involving 5 patients, 4 of whom died, which occurred in South Africa in September-October 2008.The first patient was transferred from Zambia to South Africa for medical management.The source of her infection remains undetermined.Three cases involved secondary spread of infection from the first patient, and 1 tertiary infection occurred. The OutbreakPatient 1 (Figure 1) was a travel agent who lived on an agricultural smallholding on the outskirts of Lusaka, Zambia, where she kept horses, dogs, and cats.She occasionally encountered dormice in her home, and evidence of rodent activity was found in the stables.She had visited a tourist camp on the Zambezi River on July 30 and 31, 2008, and participated in a polocrosse tournament on August 1 and 2 (but neither event occurred within the known incubation period of arenavirus infections from the date of onset of her illness).On August 30, she was cut on the shin by broken glass from a dropped bottle.Severe headache and malaise developed in the patient on September 2. On September 4, she traveled by air to attend a wedding in South Africa and was taking medication for suspected influenza.Diarrhea and vomiting developed in 4 of 110 guests who attended the wedding on September 6.Patient 1 was not affected, but she reported feeling cold and took breaks from dancing to warm herself at a fireplace.On returning to Lusaka on September 7, she was exhausted and experienced an attack of diarrhea and vomiting.