Browsing by Author "Simulundu Edgar"

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Evidence of multiple bacterial, viral, and parasitic infectious disease agents in Mastomys natalensis rodents in riverine areas in selected parts of Zambia
(2025-12-31) Munjita Samuel Munalula; Kalonda Annie; Mubemba Benjamin; Vanaerschot Manu; Tato Cristina; Mwakibete Lusajo; Tembo John; Chitanga Simbarashe; Changula Katendi; Kajihara Masahiro; Muleya Walter; Sawa Hirofumi; Takada Ayato; Bates Matthew; Munsaka Sody; Simulundu Edgar
Identification of MHC Alleles Associated With Disease Resistance/Susceptibility In Smallholder Cattle In Zambia
(2021-4-1) Silwamba Isaac K.; Simuunza Martin; Ndebe Joseph; Simulundu Edgar; Mainda Geoffrey; Muma John B.
Background: The occurrence of Major Histocompatibility complex (MHC) alleles associated with resistance to Mastitis, Bovine Leukaemia Virus (BLV), Theileriosis, Foot and Mouth Disease (FMD) and susceptibility Dermatophilosis in African cattle is ill defined. Methods: Here, we used manual annotation to screen for five MHC alleles previously known to be associated with resistance/susceptibility to these diseases from a database of alleles sequenced from 846 cattle in Zambia. Results: Overall, we found 28 (3.3%), 21 (2.6%), 55 (6.5%), and 15 (1.8%) animals with resistance alleles to Mastitis, BLV, Theileriosis, FMD and 39 (4.6%) animals with susceptibility alleles to Dermatophilosis, respectively. Conclusion: This study provides the first evidence of resistance/susceptibility alleles in smallholder cattle in Zambia and the data could aid strategies for breeding cattle with enhanced resistance to disease in endemic countries.
Phylogenetic Analysis of Newcastle Disease Virus Isolated from Poultry in Live Bird Markets and Wild Waterfowl in Zambia
(2024-2-8) Kalonda Annie; Saasa Ngonda; Kajihara Masahiro; Nao Naganori; Moonga Ladslav; Ndebe Joseph; Mori-Kajihara Akina; Mukubesa Andrew Nalishuwa; Sakoda Yoshihiro; Sawa Hirofumi; Takada Ayato; Simulundu Edgar
Poultry production is essential to the economy and livelihood of many rural Zambian households. However, the industry is threatened by infectious diseases, particularly Newcastle disease virus (NDV) infection. Therefore, this study employed next-generation sequencing to characterise six NDV isolates from poultry in Zambia’s live bird markets (LBMs) and wild waterfowl. Four NDV isolates were detected from 410 faecal samples collected from chickens in LBMs in Lusaka and two from 2851 wild birds from Lochinvar National Park. Phylogenetic analysis revealed that the four NDVs from LBM clustered in genotype VII and sub-genotype VII.2 were closely related to viruses previously isolated in Zambia and other Southern African countries, suggesting possible local and regional transboundary circulation of the virus. In contrast, the two isolates from wild birds belonged to class I viruses, genotype 1, and were closely related to isolates from Europe and Asia, suggesting the possible introduction of these viruses from Eurasia, likely through wild bird migration. The fusion gene cleavage site motif for all LBM-associated isolates was 112RRQKR|F117, indicating that the viruses are virulent, while the isolates from wild waterfowl had the typical 112ERQER|L117 avirulent motif. This study demonstrates the circulation of virulent NDV strains in LBMs and has, for the first time, characterised NDV from wild birds in Zambia. The study further provides the first whole genomes of NDV sub-genotype VII.2 and genotype 1 from Zambia and stresses the importance of surveillance and molecular analysis for monitoring the circulation of NDV genotypes and viral evolution.
Potential Causes of Acaricide Resistance in Rhipicephalus and AmblyommaTicks (Acari: Ixodidae) in Namwala District, Zambia
(2022-1-3) Sichibalo Karen; Changula Katendi; Mumba Chisoni; Mwila Natasha; Chibesa Kennedy; Mubemba Benjamin; Nalubamba King S; Muleya Walter; Simulundu Edgar; Chitanga Simbarashe
Acaricide resistance in ticks poses a great threat to livestock production in many parts of the world where ticks are a problem. The objectives of this study were to screen for acaricide resistance in Rhipicephalus and Amblyomma ticks using phenotypic and molecular assays, and to assess current tick control practices used by cattle farmers in the traditional sector of Namwala District. The larval packet test was used to screen for acaricide resistance in ticks covering concentrations up to twice the discriminatory dose for amitraz, diazinon and cypermethrin. Genetic mutations associated with resistance to amitraz (A22C-T8P and T65C-L22S), and organophosphates/ pyrethroids (G1120A) were screened using polymerase chain reaction and sequencing. Information on tick control practices at the household level was collected using a semi-structured questionnaire. Intermediate resistance (21-50%) to amitraz and cypermethrin was detected in both Rhipicephalus and Amblyomma ticks, with both tick genera showing susceptibility to diazinon (<10%). None of the ticks in this study had the reported acaricide resistance-conferring molecular markers that were screened for. The findings suggest that the resistance detected in the studied tick population may be due to other mechanisms yet to be identified. Tick control practices observed amongst the farmers, such as the incorrect use of acaricide concentrations and rotations, could be fuelling the development of acaricide resistance. Considering that acaricide treatment is the mainstay of tick control in the country, it is thus, critical to comprehensively unravel the factors contributing to treatment failure as this would allow for the application of appropriate remedial actions for effective tick control in Zambia.