Venance Theophil Msoffe

Mastomys natalensis is a widespread rodent species in sub‐Saharan Africa and is increasingly recognised as an important component of food systems in some communities. However, rodents may harbour gastrointestinal helminths with potential implications for animal health, food safety, and zoonotic disease transmission. Information on gastrointestinal helminth infections in M. natalensis and the response of these parasites to anthelmintic treatment is limited. This study investigated the prevalence and diversity of gastrointestinal helminths in M. natalensis and evaluated changes in helminth egg burden following treatment with Ivermectin. A total of 90 adult M. natalensis , comprising 43 males and 47 females, were captured, and their faecal samples were examined for gastrointestinal helminth eggs. Identified helminths were characterised and their prevalence was estimated with 95% confidence intervals. Following baseline assessment, the rodents were allocated to ‐treated and untreated control groups. Faecal egg counts, expressed as eggs per gram of faecal sample (EPG), were monitored every 14 days over an eight‐week period. The change in egg burden was assessed using faecal egg count reduction (FECR). Five gastrointestinal helminth taxa were identified, of which Hymenolepis diminuta was the most prevalent (39%; 95% CI: 29.6–49.3%), followed by Physaloptera spp. (29%; 95% CI: 20.6–39.1%), Rodentolepis nana (12%; 95% CI: 6.8–20.3%), Strongyloides spp. (11%; 95% CI: 6.1–19.1%), and Trichuris spp. (9%; 95% CI: 4.6–16.7%). In the Ivermectin‐treated rodents, mean EPG declined substantially across all five helminth taxa between baseline and weeks post‐treatment. The highest egg reductions were observed for H. diminuta (96.4%) and Trichuris spp. (96.2%), followed by Strongyloides spp. (90.9%), Physaloptera spp. (85.5%), and R. nana (80.0%). The untreated control group showed comparatively little change in overall helminth egg burden. Sex‐specific analyses showed substantial reductions in both males and females over the same period, except for, R. nana females, where egg counts showed an increase. These findings indicate the potential value of Ivermectin in reducing gastrointestinal helminth egg shedding by M. natalensis . Further studies with larger sample sizes, over a longer period, and appropriate experimental replication are warranted to validate treatment with the anthelminth and its implications for animal health, food safety, and potential zoonotic transmission.

The proximity of humans to small mammals and their ectoparasites at wildlife-human interfaces in Africa creates favorable conditions for the spillover of zoonotic pathogens. Anaplasmaceae and Rickettsiaceae bacteria are emerging threats due to their genomic adaptability and resilience to environmental changes. This systematic review and meta-analysis examined the distribution and prevalence of these pathogens in African small mammals and their ectoparasites. A comprehensive search across five electronic databases yielded 37 studies meeting predefined inclusion and exclusion criteria. The most frequently reported pathogens were Rickettsia felis (11 studies), Rickettsia massiliae (8 studies), and Rickettsia typhi (7 studies). A meta-analysis using a random-effects model was conducted separately for small mammals and ectoparasites. In small mammals, the highest prevalence was observed for Anaplasma spp. (15.17%; 95% CI 8-26.9%), Rickettsia helvetica (14.65%; 95% CI 9.09–22.75%), R. felis (12%; 95% CI 6.13–22.18%), R. massiliae (10.75%; 95% CI 0.6-70.55%), and Ehrlichia spp. (10.35%; 95% CI 4.13–23.66%). Among ectoparasites, the highest prevalence was found in ticks for R. africae (41.53%; 95% CI 13.53–76.33%) and R. massiliae (30.55%; 95% CI 8.96–66.29%). In fleas, R. felis (21.68%; 95% CI 8.67–44.68%) was most prevalent. This analysis underscores the importance of molecular detection tools, such as the combination of quantitative real-time polymerase chain reaction (qPCR) and sequencing for detection and identification of Rickettsiales, and highlights the dominance of R. africae, R. felis, and R. massiliae in ectoparasites, particularly in Eastern and Northern Africa. The study also underscores the impact of sample size and geographical regional differences in prevalence estimates. This review was registered in the international database of Prospectively Registered Systematic Reviews (PROSPERO) with ID: CRD42024552324.

Rickettsia and Anaplasma are Gram-negative, nonmotile, obligate intracellular bacteria in the order Rickettsia les. While various studies have been conducted on these threatening pathogens in humans and domestic animals, the potential role of small mammals as reservoir in zoonotic transmission is poorly understood in Tanzania. This study investigated the prevalence and identity of Rickettsia and Anaplasma infecting small mammals captured at wildlife-human interfaces in Iringa and Morogoro, Tanzania. A total of 371 blood samples were analyzed using conventional PCR and DNA fragment sequencing, targeting approximately 424 bp of the 16S rRNA gene for Anaplasma and 383 bp of the citrate synthase ( gltA ) gene for Rickettsia . Anaplasma spp. DNA was detected in 9.7 %, and Rickettsia spp. in 6.74 % of the samples. Rattus rattus exhibited the highest prevalence for both Anaplasma (21.43 %) and Rickettsia (28.57 %). Two Anaplasma species ( A. bovis and A. ovis ) and three Rickettsia species ( R. asembonensis , R. felis and R. typhi ) were confirmed through sequence analysis. This study highlights the presence of Anaplasma and Rickettsia DNA in captured rodents, indicating the potential role of rodents in the maintenance and transmission of these pathogens, especially at wildlife–human interfaces, also reports the presence of R. asembonensis in rodents for the first time in Tanzania.

Bartonellosis is a vector-borne disease which is increasingly threatening the health of humans and animals worldwide consequent to the growing wildlife-animals-human interactions. Little is known about the epidemiology of this disease in Tanzania. In this study we investigated and characterized Bartonella species in small mammals’ ectoparasites from potentially high-risk areas in the country. A total of 141 ectoparasites pools of mites, fleas, ticks, and lice were analyzed using conventional PCR and sequencing. Bartonella DNA was detected in 34.8 % of the tested ectoparasite pools, with mites at 32.9 %, fleas at 40 %, ticks at 12.5 %, and lice at 50 %. Phylogenetic analysis showed that the Bartonella spp. genotypes were closely related to those found in Uganda, Kenya, and South Africa. Different genotypes with independent haplotypes were observed, although most Bartonella spp. from fleas shared the same haplogroup. The confirmed presence of Bartonella elizabethae and Bartonella tribocorum in field and house rodents emphasizes the prevailing transmission risk of zoonotic infections in the study areas and beyond. Screening of humans, companion animals, and livestock in potentially high-risk areas in Tanzania is necessary in order to inform the development of responsive surveillance and control strategies.

Trichuriosis is a disease in mammals caused by the whipworms of the genus Trichuris. These worms are known for the high disease burden they cause in humans and domestic animals, especially in sub-Saharan Africa. In this study, we investigated the prevalence and seasonal variations of Trichuris worms in multimammate rats (Mastomys natalensis). The study was conducted between January and November 2021 in Tanzania, in two regions (Morogoro and Iringa) that differ in their eco-climatic conditions. Removal trapping was conducted using Sherman^® live traps during the rainy and dry seasons. The gastrointestinal tracts of captured rodents were screened for the presence of Trichuris worms, which were identified using morphological keys. A total of 200 M. natalensis rats were collected from each of the regions, with 100 animals in each season. For Morogoro, the overall prevalence of Trichuris worms in M. natalensis was 36% (n = 72), of which 42% (n = 42) and 30% (n = 30) were for the rainy and dry seasons, respectively. For Iringa, the overall prevalence was 65% (n = 130), of which there were 80% (n = 80) and 50% (n = 50) for the rainy and dry seasons, respectively. Trichuris worm infections were significantly higher during the rainy season in Iringa than in Morogoro; however, no significant difference in infections between males and females was noted in either region or season. Other helminths detected were Strongyloides spp., Capillaria spp., Hymenolepis spp. and eggs of a helminth that has yet to be confirmed, possibly an Anoplocephalid species. Since M. natalensis is the most important pest species in sub-Saharan Africa, and is a carrier of several zoonotic helminths, there is a need for improved surveillance of helminths infections in the studied regions, in order to establish strategic control programs to reduce their adverse impacts on health.

Background: The antimicrobial resistance catastrophe is a growing global health threat and predicted to be worse in developing countries. Phages for Global Health (PGH) is training scientists in these regions to isolate relevant therapeutic phages for pathogenic bacteria within their locality, and thus contributing to making phage technology universally available. Materials and Methods: During the inaugural PGH workshop in East Africa, samples from Ugandan municipal sewage facilities were collected and two novel Escherichia coli lytic phages were isolated and characterized. Results: The phages, UP19 (capsid diameter ∼100 nm, contractile tail ∼120/20 nm) and UP30 (capsid diameter ∼70 nm, noncontractile tail of ∼170/20 nm), lysed ∼82% and ∼36% of the 11 clinical isolates examined, respectively. The genomes of UP19 (171.402 kb, 282 CDS) and UP30 (49.834 kb, 75 CDS) closely match the genera Dhakavirus and Tunavirus , respectively. Conclusion: The phages isolated have therapeutic potential for further development against E. coli infections.

Rodents play an important role in the transmission of zoonotic diseases. This study investigated the prevalence of Leptospira spp. and Bartonella spp. in Mastomys natalensis and its ectoparasites (fleas and mites) in selected villages of Morogoro, Tanzania. Mastomys natalensis were captured live in fallow habitats using Sherman^® traps and anesthetized using Halothane. Blood samples were obtained from the retroorbital sinus Ectoparasites were removed from the fur using a hard brush and preserved in 70 % ethanol. Real time–qPCR was used to detect Leptospira spp. and Bartonella spp. from Mastomys natalensis blood and ectoparasites respectively. The study revealed a relatively larger number of males than females captures. Leptospira spp. was demonstrated in one out of 100 Mastomys natalensis. For Bartonella spp., prevalence of (14 %) was recorded in mites with a higher proportion in mites from adult male Mastomys natalensis than females. Upon Sanger sequencing, four positive samples showed a complete sequence of the ITS gene. Indicating that all samples belonged to Uncultured Bartonella. Low prevalence of Leptospira spp. and a high prevalence of Bartonella spp. was observed in Mastomys natalensis. Further exploration of rodent pathogens is recommended to raise awareness of the role of commensal rodents in disease transmission via their ectoparasites.