NAIROBI, 23 Feb 2005 (IRIN) - Médecins Sans Frontières (MSF) has sent two teams to an area in northeastern Democratic Republic of Congo (DRC) where an outbreak of pneumonic plague had been reported.

In a statement issued in Nairobi on Tuesday, MSF said an exploratory mission from 14-16 February found 93 cases of the disease in the Dingila health zone, which includes Zonia, Kana and Mambenge, all in northeastern Orientale Province.

Reports indicated that the epicentre of the outbreak was in the town of Zobia, around 190 km from the town of Buta, MSF said.

"One MSF team will focus on Zobia, while the second will follow the main routes," it said. "This second team will identify and treat those that have recently fled Zobia due to violence and fear of contracting plague."

MSF said the disease was a form of plague, which primarily attacks the lungs.

"While it is endemic to this region of the DRC, the current outbreak is unusual in the number of people affected," MSF reported.

Pneumonic plague is virulent, spreading between humans through airborne transmission - such as coughs and sneezes - and is quickly fatal. The incubation period ranges from 24 to 72 hours and death through asphyxiation comes within one day, MSF reported.

Plague is caused by the Yersinia Pestis bacteria and primarily affects wild animals such as rats, Alain Decoux, the head of mission for MSF in the DRC, was quoted as saying.

He added: "Since transmission to humans often occurs due to bites from infected fleas, a commonly held belief is that the way to stop the spread is to exterminate the rat population. In fact, this worsens the situation as it deprives the fleas of their blood supply, which means that they are more likely to seek out alternatives such as humans."

MSF said plague could easily be cured through a course of antibiotics, provided that the patient was found in time.

However, the organisation said, breaking the chain of transmission is difficult as sufferers need to be strictly isolated during the period of their illness.

"Doing so in severely underdeveloped areas, such as around Buta, is a major challenge," Decoux said.

He said the nature of the region affected made the work of MSF much more difficult.

"The fact that Zobia is a diamond producing area results in a high level of insecurity," he said. "Clashes between forces in the area coming as recently as 14 February affect the MSF teams, as well as causing the population to scatter widely. The result is that plague sufferers are hard to identify in time."