Prevalence of Rickettsia typhi in rodent fleas from areas with and without previous history of plague in Mbulu district, Tanzania
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Date
2019-12-16
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Abstract
Rickettsial diseases are worldwide emerging arthropod
borne zoonoses that are caused by an obligate
intracellular Gram-negative bacterium often found in
vector fleas (Abdad et al., 2019; Noh et al., 2017).
Rickettsioses are traditionally divided into the spotted
fever, typhus, and the scrub typhus groups (Mcleod et al.,
2004; Giulieri et al., 2012).
Murine typhus, also called endemic typhus or flea-
borne typhus is caused by Rickettsia typhi (Civen and
Ngo, 2008). The disease is transmitted by fleas
(Xenopsylla cheopis) found on rodents (Eremeeva et al.,
2008). People get murine typhus when rodent flea faeces
containing the rickettsial agents contaminate the bite
sites or other skin openings during feeding (La Scola et
al., 2000). The conjunctiva can also be the port of entry
for R. typhi (Noden et al., 2017). Similar to plaguemurine typhus would occur in areas where rodents and
the fleas are abundant mostly in farms, forests and
residential houses (Laudisoit et al., 2014).
Limited studies on murine typhus have been done in
Tanzania, specifically in Mbeya and Moshi districts by Dill
et al. (2013) and Prabhu et al. (2011). However, more
extensive studies have been done in other countries,
such as the serological evidence of exposure to R. felis
and R. typhi in Australian veterinarians by Teoh et al.
(2017) and the short report on murine typhus in Caldas
Colombia (Hidalgo et al., 2008).
Apart from the limited information on murine typhus in
Tanzania, little is known on its prevalence in the areas
with previous history of Yersinia pestis plague, such as
Mbulu district. Since murine typhus transmission cycle is
similar to that of plague, there is the likelihood that
murine typhus is prevalent in Tanzania in areas with
previous history of plague. Mbulu District is known as one
of the hotspots of plague in Tanzania (Makundi et al.,
2008). The outbreak was revealed in some of villages
including Tumati and Arri in the Division of Dongobesh in
Mbulu, where 35 cases of plague were initially reported,
with six deaths (Makundi et al., 2008). The victims had
clinical symptoms of plague, including buboes, high fever,
chills, headache, weakness, vomiting, nausea and
prostration (Ben-Ari et al., 2011; Leirs et al., 2010). This
study aimed at detecting R. typhi in rodent fleas by
conventional polymerase chain reaction (PCR) from
areas with and without previous history of plague in
Mbulu District. This information will contribute to the
design of disease control strategies of murine typhus and
other rickettsial diseases in the future.
MATERIALS AND METHODS
(3°45'00.0"S 35°20'00.0"E) with the altitude ranging from 1930 to
2250 m above sea level (Ziwa et al., 2013). This involved two
villages with and without previous history of plague, namely Endesh
and Mongahay respectively (Figure 1). Samples were collected in
three habitats, agricultural land, forest and inside houses in both
villages.
Description
Vol. 14(2), pp. 65-70, February, 2020
Keywords
Polymerase chain reaction (PCR), plague, prevalence, Rickettsia typhi, rodents.
Citation
http://www.academicjournals.org/AJMR