0521779407-13 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:15
894 Leptospirosis, Relapsing Fever■Organism is ubiquitous in nature and found in many animals
(rodents, cattle, dogs, etc.) that serve as reservoirs by being asymp-
tomatic carriers, excreting the organism in urine and contaminat-
ing soil and water. Humans become infected by direct contact with
infected animals or by exposure to soil or water that is contami-
nated. Increased risk seen in abattoir workers, sewer workers (direct
contact with rats or material contaminated with infected rat urine),
cattle ranchers, the urban homeless (rat exposure). Also identified
in adventure travelers (eg, white water rafting).
■Relapsing fever caused by Borrelia recurrentis and other Borrelia
species
■Louse-borne disease causes epidemic infection, is due to B. recurren-
tis and is transmitted to humans by the human body louse (Pedicu-
lus humanus); tick-borne disease caused by other Borrelia species
and transmitted to humans by soft ticks (Ornithodoros) that usually
reside in mountainous areas (1,500–6,000 feet); major reservoir for
tick-borne infection is rodents
■Rat-bite fever caused by Spirillium minus, a spirochete found in the
mouth of rodents; transmission to humans follows the bite of a col-
onized animalSigns & Symptoms
■Leptospirosis is classically a biphasic illness. The first or “septicemic”
phase is characterized by acute onset of high fever, chills, severe
myalgias and headaches, conjunctival suffusion, abdominal pain
with anorexia, nausea, vomiting and diarrhea (severe pain in back
and calf muscles, and conjunctival suffusion are characteristic fea-
tures of disease). A brief (1–3 days) period of improvement is followed
by the “immune” phase, characterized by a recurrence of the sys-
temic symptoms seen in the first phase, but in milder form, and the
onset of meningitis, uveitis, adenopathy and rash. Second phase per-
sists from several days to several weeks and resolves spontaneously.
■Manifestations of louse-borne and tick-borne relapsing fever
similar: a nonspecific illness with abrupt onset of high fever, chills
and rigors, headache, myalgias, arthralgias and confusion most
common presentation; hepatosplenomegaly, rash, irits, myocardi-
tis and neurologic abnormalities (CN palsy, seizure, meningitis) less
common; after 3–10 days, symptoms abate only to be followed by
a relapse in 1–2 weeks; 3–10 relapses may occur, each milder and
shorter than the previous one, until the disease “burns out”