Seasonal abundance and epidemiological indices of potential plague vectors Dinopsyllus lypusus (Siphonaptera: Hystrichopsyllidae) and Ctenophthalmus calceatus (Siphonaptera: Ctenophthalmidae) on rodents captured from three habitat types of Hatcliffe and Dzivarasekwa suburbs of Harare, Zimbabwe.

The seasonal abundance of Dinopsyllus lypusus Jordan and Rothschild and Ctenophthalmus calceatus Waterson (potential vectors of plague in southern Africa) were studied on rodent hosts captured in selected habitat types of two periurban suburbs of Harare, Zimbabwe. Removal trapping was used to capture the rodents, from which fleas were collected and identified. Prevalence (proportion of animals infested) and specific flea index (SFI = number of fleas per animal) were calculated for each species of rodent host. Cohabitation of the two flea species on the host and its implications were also assessed. In total, 1,083 rodents belonging to nine species were trapped and over 97% of the total captures comprised of four species; Mastomys natalensis Smith, Rattus rattus L., Tatera leucogaster Peters, and Rhabdomys pumilio Sparrman. In total, 735 D. lypusus and 335 C. calceatus were recorded on these four common rodent species. Population density of D. lypusus as measured by prevalence and SFI varied from 13.4 to 53.3% and 0.2-1.5, respectively, while that of C. calceatus varied from 8.2 to 26.7% and 0.2-0.6, respectively. For all rodent species captured, both prevalence and SFI of D. lypusus and C. calceatus were highest during the cold-dry season, followed by the hot dry season, with the hot-wet season recording the lowest indices. Overall cohabitation was highest during the cold-dry season and nonexistent during the hot-wet season. Our findings on the abundance and ecology of D. lypusus and C. calceatus suggest that their roles in the transmission of plague in Zimbabwe need further investigation.

Seasonal abundance of plague vector Xenopsylla brasiliensis from rodents captured in three habitat types of periurban suburbs of Harare, Zimbabwe.

The study was aimed at determining the seasonal abundance of Xenopsylla brasiliensis, an important vector of plague in Zimbabwe, from rodent hosts captured in selected habitat types of two periurban suburbs of Harare, Zimbabwe. The removal-trapping method was used to capture the rodents, from which fleas were collected and identified. Percentage incidence index (PII) and specific flea index (SFI) were calculated for X. brasiliensis in relation to rodent species host. Mastomys natalensis, Rattus rattus, Tatera leucogaster, and Rhabdomys pumilio were the rodent species present in the study areas and all species were infested with X. brasiliensis. PII for T. leucogaster in relation to X. brasiliensis was significantly higher (p < 0.05) compared with that of the other rodent species and T. leucogaster also recorded the highest SFI, whereas R. pumilio recorded the lowest indices. In both formal and informal settlements, the highest PII of X. brasiliensis was attained for M. natalensis, followed by R. rattus. In the cultivated habitat, T. leucogaster recorded the highest indices and R. pumilio the lowest. X. brasiliensis was found to cohabitat with Dinopsyllus lypusus and Ctenophthalmus calceatus on M. natalensis, R. rattus, and T. leucogaster. No cohabitation was recorded for R. pumilio. For all the rodent species captured, both the PII and SFI of X. brasiliensis were highest during the hot-dry season, followed by the hot-wet season, with the cold-dry season recording the lowest indices. The overall cohabitation was highest during the hot-dry season and lowest during the hot-wet season. The findings of the present study fit the reported occurrence of plague outbreaks during the hot-dry season in periurban Zimbabwe.