Epidemiology - Coxiella burnetii

Epidemiology

Q fever like other human rickettsial infection is a zoonotic dis-ease transmitted from infected animals to humans.

◗ Geographical distribution

C. burnetii infection is common in domestic livestock in manyparts of the world. C. burnetii infection in birds and animals has been documented by serological studies. Sporadic cases of human infections have been reported.

◗ Habitat

C. burnetii are intracellular pathogens in infected livestock andalso in humans.

◗ Reservoir, source, and transmission of infection

Q fever is a zoonosis distributed worldwide. Farm animals, such as sheep, cattle, and goats as well as cats, dogs, and rabbits are primary reservoirs of infection. Ixodid ticks are responsible for transmitting the disease to rodents and domestic animals and for maintaining infection in these animals.

C. burnetii infection in ticks is transmitted transovariallyto progeny. Coxiella are excreted in the feces and survive in dried feces over a long period of time. In infected animals, Coxiellaare excreted in the milk and particularly in their prod-ucts of conception during parturition of these animals. These bacteria contaminate surroundings of the animals, where they remain as potential source of infection to humans for months.