The rodent hosts of the Lassa fever virus breed frequently producing large numbers of offspring (particularly in the case of the Multimammate Mouse, M. Natalensis). These rodents are numerous in the savannas and forests of west, central, and east Africa. In addition, Mastomys readily colonize human homes and in particular areas where food is stored. Once they are infected with Lassa fever, these rodents are able to excrete virus in urine for an extended period of time, maybe for the rest of their life. These factors contribute to the relatively efficient spread of Lassa virus from infected rodents to humans and make food storage, cooking and processing important areas of public health attention. In recent outbreaks of Lassa fever in Nigeria large scale food processing and storage was implicated in the amplification of the virus. The consumption of ground cassava, known as garri was particularly concerning, because people sometimes consume it mixed with cold water, a preparation method which does not kill the Lassa virus. Further research is needed in this area.
