A survey of the vectors of spotted fever group Rickettsiae and
of murine typhus was carried out in Rahat, a Bedouin town in the Negev Desert,
where the diseases are endemic. Houses with known cases of spotted fever group
Rickettsiae or murine typhus were compared with those without reported clinical
cases. A neighboring Jewish community, Lehavim, where no cases of spotted fever
group Rickettsiae and murine typhus were reported in recent years, was used as
a control. In the houses of patients with spotted fever group Rickettsiae in
Rahat, an average of 7.4 times more ticks were found than in control houses.
Out of 190 ticks isolated from sheep and goats or caught by flagging in Rahat,
90% were Rhipicephalus sanguineus (Latreille), 7.9% Rhipicephalus
turanicus Pomerantzev, and 2.1% were Hyalomma sp. In the houses of
patients with murine typhus, three times more rats were caught and, on the
average, each rat was infested with 2.2 times more fleas than rats in the
control houses. Out of 323 fleas collected from 35 Norwegian rats (Rattus
norvegicus Berkenhout), 191 were Xenopsylla cheopis Rothschild and
132 Echidnophaga murina Tiraboschi. Thus, there was a six to seven times
higher probability of encountering a tick or flea vector where infections had
occurred than in control houses in Rahat. The percentage of rats seropositive
to Rickettsia typhi was similar in study and control households (78.3
and 76.2, respectively). In the control settlement, Lehavim, only three Mus
musculus L. were caught, which were not infested with ectoparasites and
their sera were negative for murine typhus. Out of 10 dogs examined in this
settlement, 15 R. sanguineus and eight specimens of the cat flea (Ctenocephalides
felis felis Bouché) were isolated. No rats were caught in this settlement.
These data indicate that there is a correlation among the density of domestic
animals, their ectoparasites, and the incidence of spotted fever group
Rickettsiae and murine typhus in Rahat (A 135).
The prevalence of Bartonella spp. in wild rodents was
studied in 19 geographical locations in Israel. One hundred and twelve
rodents belonging to five species (Mus musculus, Rattus rattus, Microtus
socialis, Acomys cahirinus and Apodemus sylvaticus) were included in
the survey. In addition, 156 ectoparasites were collected from the rodents.
Spleen sample from each rodent and the ectoparasites were examined for the
presence of Bartonella DNA using high resolution melt (HRM) real-time PCR. The
method was designed for the simultaneous detection and differentiation of eight
Bartonella spp. according to the nucleotide variation in each of two
gene fragments (rpoB and gltA) and the 16S–23S intergenic spacer (ITS) locus,
using the same PCR protocol which allowed the simultaneous amplification of the
three different loci. Bartonella DNA was detected in spleen samples of 19 out of
79 (24%) black rats (R. rattus) and in 1 of 4 (25%) Cairo spiny mice (A. cahirinus). In
addition, 15 of 34 (44%) flea pools harbored Bartonella DNA. Only rat flea (Xenopsyla
cheopis) pools collected from black rats (R. rattus) were positive
for Bartonella DNA. The Bartonella spp. detected in spleen samples from
black rats (R. rattus) was closely related to both B. tribocorum and
B. elizabethae. The species detected in the Cairo spiny mouse (A. cahirinus)
spleen sample was closely related to the zoonotic pathogen, B. elizabethae.
These results indicate that Bartonella species are highly prevalent in suburban
rodent populations and their ectoparasites in Israel (A 136).