  We prove a Central Limit Theorem for the proportion of infected individuals
for an epidemic model by dealing with a discrete time system of simple random
walks on a complete graph with n vertices. Each random walk makes a role of a
virus. Individuals are all connected as vertices in a complete graph. A virus
duplicates each time it hits a susceptible individual, dying as soon as it hits
an already infected individual. The process stops as soon as there is no more
viruses. This model is closely related to some epidemiologial models like those
for virus dissemination in a computer network.
