by Olatunji Saliu

ABUJA, Sept. 24 (Xinhua) -- The number of people killed in a cholera outbreak hitting two out of Nigeria's six northeastern states has risen to 97, according to United Nations data.

Local authorities on Sunday confirmed that 36 people were killed by the water-borne disease in Borno, local daily The Guardian reported on Monday, citing data from the United Nations Office for the Coordination of Humanitarian Affairs (UNOCHA).

A total of 3,126 cases of acute watery diarrhea (AWD) have been recorded in the two northeastern states of Borno and neighboring Yobe so far, according to the report.

Laboratory tests later confirmed the AWD cases as cholera, a local official told Xinhua.

The Nigerian Center for Disease Control declined to comment on the latest death toll, but confirmed more than 16,353 cholera-related cases have been recorded so far in Nigeria since the beginning of the year.

Last Friday, 61 people were confirmed in cholera-related deaths and 50 others hospitalized in Yobe, according to government data.

The government of Yobe said six local areas have so far been affected by the disease.

Cholera is a highly virulent disease characterized in its most severe form by a sudden onset of acute watery diarrhea that can lead to death.

Borno has 2,137 suspected cases of cholera across eight local districts.

As of Sept. 20, the state had recorded a fatality rate of 1.6 percent in the affected areas, according to the government of Borno.

Inadequate sanitation facilities in the affected local communities and flooding resulting from recent heavy rains are likely causes of the outbreak, said Muhammad Kawuwa, commissioner for health in Yobe.

"Some of the AWD cases were caused by Vibrio bacteria which causes cholera," Kawuwa said.

Over 795 patients were successfully treated and discharged in the past two months, the official said.