A new type of arenavirus has been identified by experts at the National Institute for Communicable Diseases (NICD) in Johannesburg as they studied the virus that caused the deaths of four people in recent weeks.

"There is no doubt we are dealing with a newly-emerged virus," said Janusz Paweska, head of the special pathology unit at the NICD in Johannesburg on Thursday.

"There are a number of these viruses in Africa, but until the last two weeks, we didn't know we were dealing with, in fact, a new virus,"said Paweska.

Working with the Centers for Disease Control in Atlanta, US, the virus was at first narrowed down to an arenavirus and then, after further study, the new arenavirus, which has yet to be named, was identified.

It was different from other arenaviruses — broken into "new world" arenaviruses which are found in South America, and "old world" arenaviruses found in parts of Africa.

"It's on its own," said Paweska, of the new virus which joins a list of about 100 new viruses identified in the last 30 years. Almost 75 percent, like the HI virus, come from animals.

Associated with a type of rodent, it is extreted in the rodent's urine and then can get onto food, or be inhaled while sweeping.

"It doesn't tend to spread from person to person, but it is dangerous in hospitals where (they) are dealing with vomiting and excreta," said Professor Robert Swanepoel, consultant to the specialist pathogens unit at the NICD.

The cases in South Africa were all traced to the treatment of Cecilia van Deventer, the first person known to have died from the virus.

The safari booking agent — who lived on the outskirts of Zambia's capital Lusaka — had been not been feeling well and had been to three different medical facilities in Zambia, but they were unable to say what was ailing her.

Blood was initially not drawn because she was "very averse" to needles, explained Swanepoel — who travelled to Zambia to retrace her footsteps.

Finally she allowed a needle prick blood test and was flown to South Africa's Morningside Medi-Clinic on 12 September in a very critical condition to be treated for a viral haemorrhagic fever.

Swanepoel said paramedic Hannes Els, who accompanied her, would have worked under very difficult conditions in the confined space of the aircraft — dealing with vomit and blood and intubation.

According to Swanepoel, when Van Deventer arrived at the Morningside Medi-Clinic, "... People were rushing around to save her life".

The Medi-Clinic has repeatedly said that it followed health protocols.

But, added Swanepoel, no matter how much protection nurses and doctors wear, and how cautious they are, there is always a chance that they could be pricked with a needle or be exposed to a condition while they focus on their patient.

Van Deventer died two days later on 14 September and Els died on 2 October. Van Deventer was cremated and her blood specimens were disposed of.

Nursing sister Gladys Mthembu was part of the team that cared for Van Deventer in the Intensive Care Unit between 12 and 14 September and she too died, on 5 October.

Contract cleaner Maria Mokubung cleaned Van Deventer's hospital room on the day Van Deventer died. The hospital insists that she followed protocols, saying they have a tick-list to prove it and don't know how she contracted it.

Mokubung challenged experts as she had been ill before working in Van Deventer's room. An autopsy found that she had meningitis related to tuberculosis at the time of her death, but closer study also found small traces of the arenavirus in her remains.

The nurse, who cared for Els, is currently receiving treatment after being involved in a "traumatic insertion of a central venous catheter", a preliminary report said.

She is receiving the antiviral Ribavirin, known to be effective for arenaviruses if taken early, as she did.

To identify the type of arenavirus, the NICD team worked with specialists at the Columbia University and at the CDC in Atlanta, who examined samples from liver, skin and blood taken under maximum biosecurity. The blood sample Van Deventer had given in Zambia was also found and sent for testing.

Professor Adriano Duse said of the work leading up to the 'eureka moment' of identify a new arena virus: "It was quite scary, draining, it involved long hours of hard work. You do get involved emotionally, but adrenalin keeps you going."

Duse is among a group of people from the Morningside Medi-Clinic and laboratory workers who are still being monitored for signs of the virus.

But, he believes, the outbreak is "nipped" and after the monitoring period ends, there should be no more cases linked to the Zambian case.

Sapa