Browsing by Author "Chibesa K"

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    Application of a Novel Proteomic Microarray Reveals High Exposure to Diarrhoeagenic
    (2024-Feb-20) Mwape K; Mubanga C; Chilyabanyama ON; Chibesa K; Chisenga CC; Silwamba S; Randall A; Liang X; Barnard TG; Simuyandi M; Chilengi R
    Diarrhoeagenic
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    Characterization of Rotavirus Strains Responsible for Breakthrough Diarrheal Diseases among Zambian Children Using Whole Genome Sequencing.
    (2023-Nov-26) Mwape I; Laban NM; Chibesa K; Moono A; Silwamba S; Malisheni MM; Chisenga C; Chauwa A; Simusika P; Phiri M; Simuyandi M; Chilengi R; De Beer C; Ojok D
    The occurrence of rotavirus (RV) infection among vaccinated children in high-burden settings poses a threat to further disease burden reduction. Genetically altered viruses have the potential to evade both natural infection and vaccine-induced immune responses, leading to diarrheal diseases among vaccinated children. Studies characterizing RV strains responsible for breakthrough infections in resource-limited countries where RV-associated diarrheal diseases are endemic are limited. We aimed to characterize RV strains detected in fully vaccinated children residing in Zambia using next-generation sequencing. We conducted whole genome sequencing on Illumina MiSeq. Whole genome assembly was performed using Geneious Prime 2023.1.2. A total of 76 diarrheal stool specimens were screened for RV, and 4/76 (5.2%) were RV-positive. Whole genome analysis revealed RVA/Human-wt/ZMB/CIDRZ-RV2088/2020/
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    Comparative analysis of cholera serum vibriocidal antibodies from Convalescent and vaccinated adults in Zambia.
    (2024-Aug-13) Ng'ombe H; Bosomprah S; Phiri B; Muchimba M; Liswaniso F; Chibuye M; Luchen CC; Chibesa K; Musukuma-Chifulo K; Mwape K; Tigere S; Silwamba S; Sinkala A; Simuyandi M; Mbewe N; Kapaya F; Cunningham AF; Chilengi R; Sack D; Chisenga CC
    Cholera is responsible for 1.3 to 4.0 million cholera cases globally and poses a significant threat, with Zambia reporting 17,169 cases as of 4th February 2024. Recognizing the crucial link between natural cholera infections and vaccine protection, this study aimed to assess immune responses post cholera infection and vaccination. This was a comparative study consisting of 50 participants enrolled during a cholera outbreak in Zambia's Eastern Province and an additional 56 participants who received oral cholera vaccinations in Zambia's Central Province. Vibriocidal antibodies were plotted as geometric mean titres in the naturally infected and vaccinated individuals. A significant difference (p < 0.047) emerged when comparing naturally infected to fully vaccinated individuals (2 doses) on day 28 against V. cholerae Ogawa. Those who received two doses of the oral cholera vaccine had higher antibody titres than those who were naturally infected. Notably, the lowest titres occurred between 0-9 days post onset, contrasting with peak responses at 10-19 days. This study addresses a critical knowledge gap in understanding cholera immunity dynamics, emphasizing the potential superiority of vaccination-induced immune responses. We recommend post infection vaccination after 40 days for sustained immunity and prolonged protection, especially in cholera hotspots.
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    Molecular Detection and Characterization of
    (2021) Chitanga S; Chibesa K; Sichibalo K; Mubemba B; Nalubamba KS; Muleya W; Changula K; Simulundu E
    Tick-borne zoonotic pathogens are increasingly becoming important across the world. In sub-Saharan Africa, tick-borne pathogens identified include viruses, bacteria and protozoa, with
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    Prevalence of Diarrhoeagenic
    (2023-Nov-17) Mwape K; Bosomprah S; Chibesa K; Silwamba S; Luchen CC; Sukwa N; Mubanga C; Phiri B; Chibuye M; Liswaniso F; Somwe P; Chilyabanyama O; Chisenga CC; Muyoyeta M; Simuyandi M; Barnard TG; Chilengi R
    Diarrhoea is a major contributor to childhood morbidity and mortality in developing countries, with diarrhoeagenic
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    Seroconversion and Kinetics of Vibriocidal Antibodies during the First 90 Days of Re-Vaccination with Oral Cholera Vaccine in an Endemic Population.
    (2024-Apr-08) Chisenga CC; Phiri B; Ng'ombe H; Muchimba M; Musukuma-Chifulo K; Silwamba S; Laban NM; Luchen C; Liswaniso F; Chibesa K; Mubanga C; Mwape K; Simuyandi M; Cunningham AF; Sack D; Bosomprah S
    Despite the successful introduction of oral cholera vaccines, Zambia continues to experience multiple, sporadic, and protracted cholera outbreaks in various parts of the country. While vaccines have been useful in staying the cholera outbreaks, the ideal window for re-vaccinating individuals resident in cholera hotspot areas remains unclear. Using a prospective cohort study design, 225 individuals were enrolled and re-vaccinated with two doses of Shanchol™, regardless of previous vaccination, and followed-up for 90 days. Bloods were collected at baseline before re-vaccination, at day 14 prior to second dosing, and subsequently on days 28, 60, and 90. Vibriocidal assay was performed on samples collected at all five time points. Our results showed that anti-LPS and vibriocidal antibody titers increased at day 14 after re-vaccination and decreased gradually at 28, 60, and 90 days across all the groups. Seroconversion rates were generally comparable in all treatment arms. We therefore conclude that vibriocidal antibody titers generated in response to re-vaccination still wane quickly, irrespective of previous vaccination status. However, despite the observed decline, the levels of vibriocidal antibodies remained elevated over baseline values across all groups, an important aspect for Zambia where there is no empirical evidence as to the ideal time for re-vaccination.
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    The Incidence and Risk Factors for Enterotoxigenic
    (2024-Mar-29) Sukwa N; Bosomprah S; Somwe P; Muyoyeta M; Mwape K; Chibesa K; Luchen CC; Silwamba S; Mulenga B; Munyinda M; Muzazu S; Chirwa M; Chibuye M; Simuyandi M; Chilengi R; Svennerholm AM
    This study aimed to estimate the incidence and risk factors for Enterotoxigenic
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    Use of an ETEC Proteome Microarray to Evaluate Cross-Reactivity of ETVAX
    (2023-May-04) Mubanga C; Simuyandi M; Mwape K; Chibesa K; Chisenga C; Chilyabanyama ON; Randall A; Liang X; Glashoff RH; Chilengi R
    Developing a broadly protective vaccine covering most ETEC variants has been elusive. The most clinically advanced candidate yet is an oral inactivated ETEC vaccine (ETVAX