Control of rickettsial infections requires . regular bathing
antibiotics
insect control
quarantine

insect control

Explanation:

The control of rickettsial infections requires the control of insects.

Rickettsial infections are caused by obligately intracellular Gram-negative bacteria that can only live inside a host organism. The host organisms are usually insects such as ticks, fleas, lice, etc. and a bite from any of the insects hosting the bacteria represents the only through which the infections are transmitted.

Hence, controlling the insects that serve as hosts for the bacteria will go a long way in controlling rickettsial infections.