3.5.1 Flea species collected from rodents
Four species of fleas X.brasiliensis, X.cheopis, D.lypusus andCtenophthalmus spp that were collected from rodent community in both plague and non-plague foci villages are all considered as potential or likely to be potential for harboring and transmitting plague infection from rodent to rodent or rodent to human being during the past human plague outbreak in Karatu plague endemic area and elsewhere, however their efficiency in plague transmission is different (Kilonzoet al ., 2006; Eisen et al ., 2007; Makundi et al ., 2008). The most efficient flea vector of plague infectious disease isX.cheopis that serves in circulating plague bacilli in both enzootic and epizootic plague periods (Eisen and Gage, 2009). The high vectoring potential of X.cheopis is depending on its exclusive characteristic of proventricular spines that provides attachment area for colonization of Y.pestis leading into formation of proventricular blockage after taking blood meal from an infected host, a situation which make X.cheopis to increase its daily biting rate for sucking blood meal with multiple regurgitation on the biting site on an attempt to unblock its proventriculus; therefore facilitating the increase of transmission of infection compared to other fleas (Gage and Kosoy, 2005; Korzun and Nikitin, 1997).
Similarly, D.lypusus and Ctenophthalmus spp are conceived as enzootic plague vectors and they also facilitate rapid transmission of the diseases during plague outbreak (Eisen and Gage, 2009; Ziwaet al ., 2013; Enscore et al ., 2020). D.lypusus andX.brasiliensis were conveyed as competent vectors for transmission of plague disease during 2007 plague outbreak in Mbulu and (1996/7) in Karatu plague endemic area (Kilonzo et al ., 2006; Makundi et al ., 2008). Furthermore, D.lypusus were reported in East Africa as a plague vector and an important enzootic flea in the maintenance of Y.pestis (Devignat, 1949; Arapet al ., 1977; Kilonzo 1992). This suggested that these flea species X.brasiliensis, X.cheopis and D.lypusus are important fleas in the transmission and maintenance of plague bacilli in plague endemic foci of Karatu district.