DISEASES TRANSMITTED BY FLEAS
a. Typhus Fever (Murine).
(1) General. Typhus fever is a rickettsial disease similar to typhus fever
(epidemic). The Rickettsial typhi (R. mooseri) is a parasite of rats that is transmitted
from rat to rat by the rat flea. When a human is bitten by an infected flea, the human
becomes infected because the flea released the infected feces while sucking blood.
(2) Signs and symptoms. The flea typhus is similar to Brill's disease
because the onset is gradual. The rash and fever are also less severe than that found
in louse-borne typhus. The rash concentrates on the trunk and disappears fairly rapidly.
The flea typhus is a mild disease and rarely progresses into pneumonia or gangrene.
(3) Treatment. The same procedures used for typhus fever (epidemic) are
applicable for typhus fever (murine).
(4) Prevention. To control rats and ectoparasites, insecticides are used for
rat runs, colonies, and nests, and rats are trapped or poisoned.
b. Plague (Bubonic Plague, Pneumonic Plague, Septicemic Plague, Pestis,
(1) General. The plague (Yersinia pestis) is an acute febrile disease of wild
and commensal rodents transmissible among these lower animal hosts, such as rats,
mice, squirrels, and to man through the bite of infected ectoparasites. This infection
may also be transmitted by droplets or sputum from a plague victim who has
pneumonia. When the victim is bitten by an infected flea, the organisms go through the
lymphatics to the lymph nodes causing them to become greatly enlarged (bubo). In this
manner, the organisms may reach the bloodstream and affect all organs. The outcome
is often fatal in cases where pneumonia or meningitis develops. The incubation period
for bubonic plague is 2 to 6 days and for the pneumonic plague, it is 3 to 4 days.
Signs and symptoms.
(a) The onset of bubonic plague is abrupt and often associated with
chills. The temperature rises rapidly from 103 to 106F and his face shows fear and
anxiety. Other signs include vomiting and the victim is thirsty. He has an unsteady gait,
generalized pains, a headache, and mental dullness. His skin becomes hot and dry, his
pulse and respiration rates increase, his face becomes edematous, and he has
gastrointestinal (GI) and pulmonary hemorrhages. The buboes (enlarged, painful,
tender lymph nodes) are commonly found in the femoral and inguinal nodes but less
commonly in the axillary and cervical nodes.