Prevention of rickettsial
infections is aimed at individual control and epidemic measures (especially in
epidemic typhus), vector and rodent control, milk pasteurization (in
Q fever),
chemoprophylaxis and immunoprophylaxis. In vector and rodent control, the main obstacle is the rise in resistance to
insecticides and
rodenticides. For this reason in vector control, apart from
insecticides, enhancement of the natural immunity acquired by animals in response to
tick infestation and vaccination with concealed tick
antigens as well as the use of
hormones,
chemosterilants and genetic manipulation can also be considered. For short-term high-risk exposure,
doxycycline may be an effective prophylaxis of illness but may not prevent
infection with
scrub typhus or
spotted fever group rickettsiae. At present, for specific prevention by vaccination, only
Q fever vaccines are available for common use. However, development of
subunit vaccines, namely immunogenic rickettsial
proteins, cloned and expressed in Escherichia coli, seems to be very promising.