Ecological assessment of rodents and flea populations and disease awareness in plague foci, Mbulu District, Northern Tanzania

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Date

2024

Journal Title

Journal ISSN

Volume Title

Publisher

Sokoine University of Agriculture

Abstract

Plague, a rodent-borne disease caused by Yersinia pestis, continues to be a major public health concern in several African countries. Disease outbreaks are influenced by various factors, including rodent population dynamics, flea infestations, human behaviors and practices and environmental conditions. Conducting comprehensive studies addressing these factors particularly in plague endemic areas is crucial for understanding their involvenment in plague persistence and developing effective preventive and control measures. In this study, several methods were used to assess different factors associated with the continued existence of plague in the plague foci, Mbulu district, Tanzania. The study was conducted between November 2019 to November 2021. To assess rodent species richness, diversity, and community structure in relation to plague persistence in different habitats, seasons and localities, a removel trapping method was applied. Findings indicated that areas with plague persistent had higher rodent abundance and species richness than non-persistent areas. Nortably, species richness was lower in-house premises compared to other habitats. Also, the study revealed three rodent community structures that varied significantly between studied habitat types, suggesting interactions influenced by available resources in the particular habitats. The population dynamics of Mastomys natalensis and Lophuromys makundii were assessed using a Capture-Mark-Recapture method. Results showed that the abundance of M. natalensis was significantly higher in farms present in plague persistent than those present in non- plague persistent locality. The dry season showed a significant increase of abundance compared to the long rain season and the short rain season. Plague persistent had a significant increase in breeding females compared to non-plague persistent localities, while in the different habitats, farms showed a significant decrease in breeding females compared to forests. Also, dry season was associated with an increase in breeding females compared to the long rain season and the short rain season. Furthermore, the abundance of L. makundii and proportion of breeding females showed a significant increase in forest present in plague persistent than non-plague persistent localities. The abundance increased significantly during the dry season and long rain season compared to the short rain season. The breeding females significantly increased during the dry and the short rain season than the long rain season. For the assessment of flea infestation of rodents, fleas ectoparasites were collected by fur brushing the captured rodents. The study aimed to determine flea infestation prevalence, community structure, and variations between localities, habitats (farn and forest) and seasons. Flea abundance did not show significant differences between localities, habitats and seasons. However, prevalence of flea infestation was significantly positively associated with the plague persistent locality and the short rain season. Also, the study revealed two broad flea community structures based on farm and forest habitats. Fluctuations in flea abundance thoughout the sampling period and the influence of household behavior (such as mat and sleeping loft) on flea abundance within house were examined using a removal method and light trap. The study found seven flea species within houses with Ctenocephalides canis being the most abundant, followed by Pullex irritans and Ctenocephalides felis. The abundance was significantly higher in dry than long rain season. Houses with sleeping bed, mattress and loft had significantly higher flea abundance than houses with bed and mat alone. Also, households that shared livestock in one roof had significantly more fleas than non-shared households.

Description

Dissertation

Keywords

Rodent population, Flea abundance, household behavior, plague persistence

Citation