Kampala - A rat population which outnumbers humans by four to one and an outbreak of plague in north-west Uganda have raised fears of an epidemic. "There is plague in West Nile" in north-western Uganda, Mr Tom Mwebesa, assistant commissioner for health services, told the state-owned New Vision newspaper. "The fear is that if we got a rat from West Nile with its fleas, and it infects those other rats in Kampala, there could be an epidemic."