There Is A Rat In My Loft! Things To Keep In Mind When Signing A Pest Control Treatment Contract Top 5 East Coast cities for ticks and Lyme Disease There are two major types of infectious diseases which can develop into epidemics: common source and host-to-host. Common source epidemics arise from a contaminated source, such as water or food, while host-to-host infections are transmitted from one infected individual to another via various, perhaps indirect, routes.. Anything causing disease is called a pathogen.See "What if I find termites in my house?''. Most pest control companies include an annual inspection with the contract and. Am I willing to pay for extra peace of mind?. The ground treatment is designed to keep termites out of the. Under louisiana state law, a termite contract's warranty only covers.