The health authorities in Nigeria have warned that the entire country is threatened by cholera outbreak. More than 350 people have been killed so far. According to reports, doctors are now monitoring cholera outbreaks in 12 out of 36 states in Nigeria. More than 6400 cases have been detected. The country's Health Ministry is alarmed. It has issued a statement warning that there is evidence the entire country is at the risk of the epidemic. Nigeria is now in a rainy season. High water level and flooding have contaminated sources of drinking water in rural areas.