KANO, Nigeria -- A Nigerian health official says a cholera epidemic has killed 71 people and infected 2,165 since November in northern Kano state.

Centre for Disease Control project director AbdulSalam Nasadi told reporters Friday that most cases are centred around Kano city, the country's second largest.

Northern Zamfara state also has recorded hundreds of cholera cases.

Nasadi said health officials have deployed to oversee cleanups and advise people on the need for cleanliness.

Lack of proper sanitation and clean water, pit toilets, mounds of uncollected garbage and storm drains blocked by garbage are among issues that contribute to health threats.

Cholera is caused by filth and dirty water. U.N. figures indicate half of Nigeria's more than 160 million people do not have safe water and a third do not have proper toilets.