Question

Explain the life cyle of murine typhus, including both the endemic cycle and the new peridomestic cycle.

Answer 1

Murine typus is a disease caused by bacteria called Rickettsia typhi. It is spread through people if they came in contact with fleas that carry R.typhi. Hence the fles act as a vector for the transmission of this disease. The fleas become infected when they bite R.typhi infected animals such as Rats, Cats and Opposum.

When the infected fleas bites an animal the flea dirt enter inside the organism and it became infected.This becteria do not spread from person to person. Signs and symptoms of this disease includes fever and chills, myalgia, loss of appetite, nausea, vomiting, stomach ache, cough and rash.

Recent studies indicates that the bacteria R. typhi shows two type of life cycle. They are endemic cycle and peridomesic cycle. The endemic life cycle is strictly maintained to a particular area. in the case of the U.S the endemic life cycle of R.typhi is concentrated in coastal and urban areas of California, Hawaii and Texas where it is maintained in rat and rat fleas and less than 100 cases are reported.

Studies conducted in California and Texas indicates that the classic rodent life cycle of bacteria has been augmented to a peridomesic life cycle that involving free ranging Cats, Dogs and opposums and their fleas.