Cholera is classified as an epidemic disease in Nigeria because it occurs in periodic, sharp outbreaks—often linked to the rainy season and poor sanitation—that see a rapid and unexpected increase in cases.

A. malaria: In Nigeria, malaria is considered endemic rather than epidemic. It is a constant, year-round health burden that accounts for 27% of global cases.

B. schistosomiasis: This is a neglected tropical disease and is generally endemic in specific communities where people come into contact with contaminated water, rather than being an epidemic disease that sweeps through the whole population in sudden waves.

C. poliomyelitis: Polio is targeted for eradication and is no longer an epidemic disease in Nigeria, which was officially certified wild-polio free in 2020.