Browsing by Author "Bosomprah, Samuel"

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Assessment of the influence of ABO blood groups on oral cholera vaccine immunogenicity in a cholera endemic area in Zambia.
(2023-Jan-23) Chisenga, Caroline C.; Bosomprah, Samuel; Chilyabanyama, Obvious N.; Alabi, Peter; Simuyandi, Michelo; Mwaba, John; Ng'ombe, Harriet; Laban, Natasha M.; Luchen, Charlie C.; Chilengi, Roma
BACKGROUND: Histo-blood group antigens (HBGAs) which include the ABO and Lewis antigen systems have been known for determining predisposition to infections. For instance, blood group O individuals have a higher risk of severe illness due to V. cholerae compared to those with non-blood group O antigens. We set out to determine the influence that these HBGAs have on oral cholera vaccine immunogenicity and seroconversion in individuals residing within a cholera endemic area in Zambia. METHODOLOGY: We conducted a longitudinal study nested under a clinical trial in which samples from a cohort of 223 adults who were vaccinated with two doses of Shanchol™ and followed up over 4 years were used. We measured serum vibriocidal geometric mean titers (GMTs) at Baseline, Day 28, Months 6, 12, 24, 30, 36 and 48 in response to the vaccine. Saliva obtained at 1 year post vaccination was tested for HBGA phenotypes and secretor status using an enzyme-linked immunosorbent assay (ELISA). RESULTS: Of the 133/223 participants included in the final analysis, the majority were above 34 years old (58%) and of these, 90% were males. Seroconversion rates to V. cholerae O1 Inaba with non-O (23%) and O (30%) blood types were comparable. The same pattern was observed against O1 Ogawa serotype between non-O (25%) and O (35%). This trend continued over the four-year follow-up period. Similarly, no significant differences were observed in seroconversion rates between the non-secretors (26%) and secretors (36%) against V. cholerae O1 Inaba. The same was observed for O1 Ogawa in non-secretors (22%) and the secretors (36%). CONCLUSION: Our results do not support the idea that ABO blood grouping influence vaccine uptake and responses against cholera.
Associations of inter-annual rainfall decreases with subsequent HIV outcomes for persons with HIV on antiretroviral therapy in Southern Africa: a collaborative analysis of cohort studies.
(2023-Dec-19) Trickey, Adam; Johnson, Leigh F.; Fung, Fai; Bonifacio, Rogerio; Iwuji, Collins; Biraro, Samuel; Bosomprah, Samuel; Chirimuta, Linda; Euvrard, Jonathan ; Fatti, Geoffrey; Fox, Matthew P.; Von, Groote P.; Gumulira, Joe; Howard, Guy; Jennings, Lauren; Kiragga, Agnes; Muula, Guy; Tanser, Frank; Wagener, Thorsten; Low, Andrea; Vickerman, Peter
BACKGROUND: Periods of droughts can lead to decreased food security, and altered behaviours, potentially affecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa. METHODS: Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981-2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre's latitude/longitude. In individual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associations between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts < 200 cells/mm RESULTS: Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32-46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07-1.32] per 10 percentile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01-1.09]). Levels of rainfall were not strongly associated with CD4 counts < 200 cell/mm CONCLUSIONS: Decreased rainfall could negatively impact on HIV treatment behaviours and outcomes. Further research is needed to explore the reasons for these effects. Interventions to mitigate the health impact of severe weather events are required.
Burden of chronic kidney diseases and underlying causes in Zambia: evidence from the global burden of disease study 2019.
(2023-Feb-18) Bosomprah, Samuel; Bjonstad, Erica C.; Musuku, John; Siyumbwa, Namasiku; Ngandu, Mwila; Chisunka, Mukobe; Banda, Patrick; Goma, Fastone; Mweemba, Aggrey
INTRODUCTION: Chronic kidney disease (CKD) has been a global public health problem and a major source of suffering and poor quality of life for those afflicted. Using data from the global burden of disease (GBD) study 2019, we estimated the magnitude of the burden of CKD as well as the underlying causes of CKD in the Zambian population. METHOD: The data used for this study were extracted from the GBD 2019 study. The GBD 2019 provides estimates of several metrics of disease burden including the commonly used disability-adjusted life year (DALYs) for over 369 diseases and injuries, and 87 risk factors and combinations of these in 204 countries and territories from 1990 to 2019. We estimated the burden of CKD as the number and rates (per 100,000 population) of DALYs, disaggregated by year, sex, and age group. We examined the underlying causes of CKD by estimating the population attributable fraction as the percentage contributions of risk factors to CKD DALY. RESULTS: The number of DALYs for CKD was estimated as 76.03 million (95% UI: 61.01 to 93.36) in 2019 compared to 39.42 million (95% UI: 33.09 to 45.90) in 1990, representing 93% increase whereas the DALYs rate per 100,000 population was estimated as 416.89 (95% UI: 334.53 to 511.93) in 2019 compared to 496.38 (95% UI: 416.55 to 577.87) in 1990, representing 16% reduction. CKD due to hypertension accounted for 18.7% of CKD DALYs and CKD due to diabetes (types 1 and 2) accounted for 22.7%, while CKD from glomerulonephritis accounted for the most DALYs at 33%. The age group most impacted from CKD were adolescents and young adults. CONCLUSION: The burden of CKD remains high in the Zambian population with diabetes, high blood pressure, and glomerulonephritis as important causes. The results highlight the need to develop a comprehensive action plan to prevent and treat kidney disease. Increasing the awareness of CKD among the public as well as adaptation of guidelines for treating patients with end stage kidney disease are important considerations.
Cohort profile: Noncommunicable diseases and ideal cardiovascular health among people living with and without HIV in Zambia and Zimbabwe (NCDzz cohort).
(2025-Feb-07) Chihota, Belinda V.; Mandiriri, Ardele; Muula, Guy; Banda, Esau; Shamu, Tinei; Bolton-Moore, Carolyn; Chimbetete, Cleophas; Bosomprah, Samuel; Wandeler, Gilles
PURPOSE: The NCDzz study is a prospective cohort of people living with and without HIV attending primary care clinics in Zambia and Zimbabwe and was established in 2019 to understand the intersection between noncommunicable diseases (NCDs) and HIV in Southern Africa. Here, we describe the study design and population and evaluate their ideal cardiovascular health (ICVH) using the Life's Simple 7 (LS7) score according to the American Heart Association. PARTICIPANTS: Antiretroviral therapy-naïve people living with HIV (PLWH) and people living without HIV (PLWOH) 30 years or older were recruited from three primary care clinics in Lusaka and Harare, and underwent comprehensive clinical, laboratory and behavioural assessments. All study measurements are repeated during yearly follow-up visits. PLWOH were recruited from the same neighbourhoods and had similar socioeconomic conditions as PLWH. FINDINGS TO DATE: Between August 2019 and March 2023, we included 1100 adults, of whom 618 (56%) were females and 539 (49%) were PLWH. The median age at enrolment was 39 years (IQR 34-46 years). Among 1013 participants (92%) with complete data, the median LS7 score was 11/14 (IQR 10-12). Overall, 60% of participants met the criteria of ICVH metrics (5-7 ideal components) and among individual components of the LS7, more females had poor body mass index (BMI) than males, regardless of HIV status (27% vs 3%, p<0.001). Our data show no apparent difference in cardiovascular health determinants between men and women, but high BMI in women and overall high hypertension prevalence need detailed investigation. Untreated HIV (OR: 1.36 (IQR 1.05-1.78)) and being a Zambian participant (OR: 1.81 (IQR 1.31-2.51)) were associated with having ICVH metrics, whereas age older than 50 years (OR: 0.46 (IQR 0.32-0.65)) was associated with not having ICVH metrics. FUTURE PLANS: Our study will be regularly updated with upcoming analyses using prospective data including a focus on arterial hypertension and vascular function. We plan to enrich the work through conducting in-depth assessments on the determinants of cardiovascular, liver and kidney end-organ disease outcomes yearly. Additionally, we seek to pilot NCD interventions using novel methodologies like the trials within cohorts. Beyond the initial funding support, we aim to collect at minimum yearly data for an additional 5-year period.
Comparing growth velocity of HIV exposed and non-exposed infants: An observational study of infants enrolled in a randomized control trial in Zambia.
(2021) Chilyabanyama, Obvious N.; Chilengi, Roma; Laban, Natasha M.; Chirwa, Masuzyo ; Simunyandi, Michelo; Hatyoka, Luiza M.; Ngaruye, Innocent; Iqbal, Najeeha T.; Bosomprah, Samuel
BACKGROUND: Impaired growth among infants remains one of the leading nutrition problems globally. In this study, we aimed to compare the growth trajectory rate and evaluate growth trajectory characteristics among children, who are HIV exposed uninfected (HEU) and HIV unexposed uninfected (HUU), under two years in Zambia. METHOD: Our study used data from the ROVAS II study (PACTR201804003096919), an open-label randomized control trial of two verses three doses of live, attenuated, oral RotarixTM administered 6 &10 weeks or at 6 &10 weeks plus an additional dose at 9 months of age, conducted at George clinic in Lusaka, Zambia. Anthropometric measurements (height and weight) were collected on all scheduled and unscheduled visits. We defined linear growth velocity as the rate of change in height and estimated linear growth velocity as the first derivative of the mixed effect model with fractional polynomial transformations and, thereafter, used the second derivative test to determine the peak height and age at peak heigh. RESULTS: We included 212 infants in this study with median age 6 (IQR: 6-6) weeks of age. Of these 97 (45.3%) were female, 35 (16.4%) were stunted, and 59 (27.6%) were exposed to HIV at baseline. Growth velocity was consistently below the 3rd percentile of the WHO linear growth standard for HEU and HUU children. The peak height and age at peak height among HEU children were 74.7 cm (95% CI = 73.9-75.5) and 15.5 months (95% CI = 14.7-16.3) respectively and those for HUU were 73 cm (95% CI = 72.1-74.0) and 15.6 months (95% CI = 14.5-16.6) respectively. CONCLUSION: We found no difference in growth trajectories between infants who are HEU and HUU. However, the data suggests that poor linear growth is universal and profound in this cohort and may have already occurred in utero.
Contraceptive use among HIV-infected women and men receiving antiretroviral therapy in Lusaka, Zambia: a cross-sectional survey.
(2016-May-12) Hancock, Nancy L.; Chibwesha, Carla J.; Bosomprah, Samuel; Newman, Jonathan; Mubiana-Mbewe, Mwangelwa ; Sitali, Elizabeth S.; Bolton-Moore, Carolyn; Mbwili-Muleya, Clara; Chi, Benjamin H.
BACKGROUND: Family planning (FP) is an essential health service and an important part of comprehensive HIV care. However, there is limited information about the contraceptive needs of people living with HIV in sub-Saharan Africa, which in turn has hampered efforts to expand and integrate FP services into existing HIV programs. METHODS: We performed a cross-sectional survey to determine FP prevalence and predictors among HIV-positive women and men attending 18 public antiretroviral therapy (ART) clinics in Lusaka, Zambia. Trained peer counselors administered the 10-question survey to those seeking care for five days at each of the target sites. RESULTS: From February to April 2014, we surveyed 7,046 HIV-infected patients receiving routine HIV services. Use of modern contraception was reported by 69 % of female ART patients and 79 % of male ART patients. However, highly effective contraceptive use and dual method use were low among women (38 and 25 %, respectively) and men (19 and 14 %, respectively). HIV disclosure status (adjusted odds ratio (AOR) = 4.91, 95 % confidence interval (CI) = 3.32-7.24 for women, AOR = 3.58, 95 % CI = 2.39-5.38 for men) and sexual activity in the last 6 months (AOR = 5.80, 95 % CI = 4.51-7.47 for women, AOR = 6.24, 95 % CI = 3.51-11.08 for men) were associated with modern contraceptive use in multivariable regression. Most respondents said they would access FP services if made available within ART clinic. CONCLUSIONS: While FP-ART integration may be a promising strategy for increasing FP service uptake, such services must focus on assessing sexual activity and advocating for dual method use to increase effective contraceptive use and prevent unintended pregnancies.
Development and validation of a novel scale for antiretroviral therapy readiness among pregnant women in urban Zambia with newly diagnosed HIV infection.
(2023-Apr-06) Mubiana-Mbewe, Mwangelwa; Bosomprah, Samuel; Saroj, Rakesh K.; Kadota, Jillian; Koyuncu, Aybuke; Thankian, Kusanthan; Vinikoor, Michael J.
BACKGROUND: Women who are newly diagnosed with HIV infection during pregnancy may not be ready to immediately initiate lifelong antiretroviral therapy (ART; called Option B +) as is recommended. Lack of "readiness" drives early disengagement from care and undermines prevention of HIV transmission to infants. Several studies have shown high early attrition of women initiating ART in pregnancy. Although poor ART uptake and adherence have been attributed to various factors including stigma, disclosure issues and structural issues, there is no standard way of determining which pregnant woman will face challenges and therefore need additional support. We developed and validated a novel ART readiness tool in Lusaka, Zambia. METHODS: The aim of this study was to develop and validate a tool that could be used to assess how ready a newly diagnosed pregnant woman living with HIV would be to initiate ART on the day of diagnosis. Using a mixed method design, we conducted this study in three public-setting health facilities in Lusaka, Zambia. Informed by qualitative research and literature review, we identified 27 candidate items. We assessed content validity using expert and target population judgment approaches. We administered the 27-item questionnaire to 454 newly diagnosed pregnant women living with HIV, who were enrolled into a randomized trial (trials number NCT02459678). We performed item reduction analysis and used Cronbach's alpha coefficient of 0.70 as threshold for reliability. RESULTS: A total of 454 pregnant women living with HIV enrolled in the study between March 2017 and December 2017; 452 had complete data for analysis. The correlation coefficient between the 27 items on the completed ART readiness scale ranged from 0.31 to 0.70 while item discrimination index ranged from -0.01 to 2.38. Sixteen items were selected for the final scale, representing three domains, which we classified as "internalized and anticipated HIV stigma", "partner support" and "anticipated structural barriers". CONCLUSION: We developed and validated a tool that could be used to assess readiness of newly diagnosed women living with HIV to initiate ART. This ART readiness tool could allow clinics to tailor limited resources to pregnant women living with HIV needing additional support to initiate and remain on ART.
Diagnostic accuracy of saliva-based testing as a Vibrio cholerae surveillance tool among naturally infected patients.
(2025-Jan-21) Chisenga, Caroline C.; Phiri, Bernard; Ng'ombe, Harriet; Muchimba, Mutinta; Liswaniso, Fraser; Bernshtein, Biana; Cunningham, Adam F.; Sack, David; Bosomprah, Samuel
Saliva, as a diagnostic medium, offers a promising alternative to blood by virtue of its non-invasive collection, which enhances patient compliance, especially in paediatric and geriatric populations. In this study, we assessed the utility of saliva as a non-invasive medium for measuring Vibrio cholerae-specific serum antibodies in naturally infected individuals. We tested paired serum and saliva samples obtained from a total of 63 patients with cholera enrolled in a cohort study. Vibriocidal antibodies assay (IgM/IgG) as markers for accurate determination was used to determine cholera-specific antibody levels. Using receiver operating characteristics (ROC) curve, we found that the best cut-off that maximizes (sensitivity + specificity) is 10 titres. At this saliva titre, the sensitivity is 76.9% (95%CI: 60.9%, 87.7%) and specificity is 80.0% (95%CI: 56.6%, 92.5%). Using Spearman's correlation coefficient, we also found evidence of a positive correlation between V. cholerae saliva and serum antibodies (rho = 0.66, P < 0.001). In conclusion, saliva-based diagnostic cholera tests have high diagnostic accuracy and would be advantageous, cheaper, and quicker for early diagnosis of severe cholera outcomes.
Early linear growth retardation: results of a prospective study of Zambian infants.
(2019-Jan-14) Chilengi, Roma; Asombang, Mah; Kadota, Jillian L.; Chilyabanyama, Obvious N.; Mwila-Kazimbaya, Katayi; Ng'ombe, Harriet; Simuyandi, Michelo; Bosomprah, Samuel
BACKGROUND: Linear growth retardation is the most dominant nutritional problem globally. We aimed to describe linear growth trajectory among infants under 2 years of age using the WHO growth velocity standards. METHOD: This was a prospective cohort study of infants enrolled at 6 weeks of age and followed up for up to 24 months in Kamwala Urban Health Centre, Lusaka, Zambia. The study was conducted between April 2013 and March 2015. Infants were enrolled if they were 6-12 weeks of age and the mother was willing to participate voluntarily and provided informed consent. Anthropometric data were collected at scheduled clinic visits at 1 month, 2 months, 3 months, then quarterly until the infant was 24 months old. We defined linear growth velocity as the rate of change in height. We estimated linear growth velocity as the first derivative of the penalized cubic spline mixed effects model. RESULTS: A total of 338 children were included in the analysis. Of these, 185 (54.7%) were female, 115 (34.1%) were born to HIV positive mothers and thus classified as HIV Exposed (HE). The mean age of children at enrollment was 1.6 months (SD = 0.15). On average, the growth velocity for 3-month length increments conditional on age were 0-3 months = 2.97 cm/3mo (95%CI = 2.69, 3.25); 3-6 months = 2.62 cm/3mo (95%CI = 2.38, 2.87); 6-9 months = 1.57 cm/3mo (95%CI = 1.43, 1.71); 9-12 months = 1.18 cm/3mo (95%CI = 1.08, 1.28); 12-15 month = 1.14 cm/3mo (95%CI = 1.02, 1.27); 15-18 months = 0.87 cm/3mo (95%CI = 0.79, 0.96); 18-21 months = 0.80 cm/3mo (95%CI = 0.72, 0.89); and 21-24 months = 0.86 cm/3mo (95%CI = 0.77, 0.96). For both boys and girls, the growth velocity in our cohort were consistently below the 3rd percentile of the WHO linear growth velocity standard. The estimated mean height and the age at which growth begins to falter were 68.6 cm (95%CI = 68.0, 69.2) and 13.6 months (95%CI = 13.2, 14.1) respectively. CONCLUSION: We found slower rate of growth among otherwise healthy Zambian infants. The data suggests that growth retardation is universal and profound in this cohort and may have already been occurring in utero.
Effect of HIV status and retinol on immunogenicity to oral cholera vaccine in adult population living in an endemic area of Lukanga Swamps, Zambia.
(2021) Luchen, Charlie C.; Mwaba, John; Ng'ombe, Harriet; Alabi, Peter I. O.; Simuyandi, Michelo; Chilyabanyama, Obvious N.; Hatyoka, Luiza M.; Mubanga, Cynthia; Bosomprah, Samuel; Chilengi, Roma; Chisenga, Caroline C.
BACKGROUND: We set out to assess the impact of human immunodeficiency virus (HIV) and micronutrient deficiency as indicated by serum retinol levels on the immune responses to Oral Cholera Vaccine (Shanchol™) in a cohort of participants in Lukanga Swamps, Zambia. Cholera remains endemic in Zambia with vaccines being the only effective preventive measures. However, the effect of these vaccines on populations living with HIV has not been widely documented. METHODS: HIV testing and confirmation was done using the Alere Determine™ HIV-1/2 and Uni-Gold™ kits while vibriocidal antibody assay was applied for vaccine immunogenicity. Serum retinol analysis was assessed by Shimadzu Prominence HCT-2010 High Performance Liquid Chromatography (HPLC). The primary outcome was log transformed geometric mean titre. RESULTS: From 47 participants screened for HIV, 51% (24) tested positive. There was a statistically significant reduction in Ogawa geometric mean ratio (GMR) by 67% (GMR = 0.33; 95% CI: -0.15, 0.76; p-value = 0.009) attributable to HIV positivity with a non-significant reduction in Inaba GMR by about 50% due to HIV positivity. When doubling of retinol levels modelled, GMR reduction against Ogawa were non-significant but that against Inaba resulted in a significant reduction in geometric mean titer (GMT) (GMT-0.33, C.I 0.16-0.66, p-value 0.002). At 1000copies/ml viral load cut off and 350 cells/μl CD4 counts, Ogawa GMT was two times higher 11.16 (95%CI: 8.20-15.19) versus 6.06 (95%CI: 4.04-9.10) in low viremia participants, and three times higher in above threshold CD4 count participants; 24.81 (95%CI: 18.94-32.50) versus 7.07 (95%CI: 5.22-9.58). CONCLUSION: Our results show that while Shanchol™ is immunogenic in both HIV+/- individuals, HIV + participants responded poorly. Viral load and CD4 count affected vaccine immunogenicity. More research is required for detailed understanding of this in order to appropriately inform policy and practice. DOI: 10.1371/journal.pone.0260552
Efficacy of the Common Elements Treatment Approach (CETA) for Unhealthy Alcohol Use Among Adults with HIV in Zambia: Results from a Pilot Randomized Controlled Trial.
(2022-Feb) Kane, Jeremy C.; Sharma, Anjali; Murray, Laura K.; Chander, Geetanjali; Kanguya, Tukiya; Skavenski, Stephanie; Chitambi, Chipo; Lasater, Molly E.; Paul, Ravi; Cropsey, Karen; Inoue, Sachi; Bosomprah, Samuel; Danielson, Carla K.; Chipungu, Jenala; Simenda, Francis; Vinikoor, Michael J.
This randomized controlled trial tested the efficacy of a multi-session, evidence-based, lay counselor-delivered transdiagnostic therapy, the Common Elements Treatment Approach (CETA), in reducing unhealthy alcohol use and comorbidities among persons living with HIV (PLWH) in Zambia. Adult PLWH with (a) unhealthy alcohol use plus mental health or substance use comorbidities, or (b) severe unhealthy alcohol use were randomized to receive a single-session alcohol brief intervention (BI) alone or BI plus referral to CETA. Outcomes were measured at baseline and a 6-month follow-up and included Alcohol Use Disorders Identification Test (AUDIT) score (primary), depression and trauma symptoms, and other substance use (secondary). We enrolled 160 participants; 78 were randomized to BI alone and 82 to BI plus CETA. Due to COVID-19, the trial ended early before 36 participants completed. Statistically and clinically significant reductions in mean AUDIT score from baseline to 6-month follow-up were observed in both groups, however, participants assigned to BI plus CETA had significantly greater reductions compared to BI alone (- 3.2, 95% CI - 6.2 to - 0.1; Cohen's d: 0.48). The CETA effect size for AUDIT score increased in line with increasing mental health/substance use comorbidity (0 comorbidities d = 0.25; 1-2 comorbidities d = 0.36; 3+ comorbidities d = 1.6). Significant CETA treatment effects were observed for depression, trauma, and several other substances. BI plus referral to CETA was feasible and superior to BI alone for unhealthy alcohol use among adults with HIV, particularly among those with comorbidities. Findings support future effectiveness testing of CETA for HIV outcomes among PLWH with unhealthy alcohol use.Clinical Trials Number: NCT03966885.
Evaluating a multifaceted implementation strategy and package of evidence-based interventions based on WHO PEN for people living with HIV and cardiometabolic conditions in Lusaka, Zambia: protocol for the TASKPEN hybrid effectiveness-implementation stepped wedge cluster randomized trial.
(2024-Jun-06) Herce, Michael E.; Bosomprah, Samuel; Masiye, Felix; Mweemba, Oliver; Edwards, Jessie K.; Mandyata, Chomba; Siame, Mmamulatelo ; Mwila, Chilambwe; Matenga, Tulani; Frimpong, Christiana ; Mugala, Anchindika; Mbewe, Peter; Shankalala, Perfect; Sichone, Pendasambo; Kasenge, Blessings; Chunga, Luanaledi ; Adams, Rupert; Banda, Brain; Mwamba, Daniel; Nachalwe, Namwinga; Agarwal, Mansi; Williams, Makeda J.; Tonwe, Veronica; Pry, Jake M.; Musheke, Maurice; Vinikoor, Michael; Mutale, Wilbroad
BACKGROUND: Despite increasing morbidity and mortality from non-communicable diseases (NCD) globally, health systems in low- and middle-income countries (LMICs) have limited capacity to address these chronic conditions, particularly in sub-Saharan Africa (SSA). There is an urgent need, therefore, to respond to NCDs in SSA, beginning by applying lessons learned from the first global response to any chronic disease-HIV-to tackle the leading cardiometabolic killers of people living with HIV (PLHIV). We have developed a feasible and acceptable package of evidence-based interventions and a multi-faceted implementation strategy, known as "TASKPEN," that has been adapted to the Zambian setting to address hypertension, diabetes, and dyslipidemia. The TASKPEN multifaceted implementation strategy focuses on reorganizing service delivery for integrated HIV-NCD care and features task-shifting, practice facilitation, and leveraging HIV platforms for NCD care. We propose a hybrid type II effectiveness-implementation stepped-wedge cluster randomized trial to evaluate the effects of TASKPEN on clinical and implementation outcomes, including dual control of HIV and cardiometabolic NCDs, as well as quality of life, intervention reach, and cost-effectiveness. METHODS: The trial will be conducted in 12 urban health facilities in Lusaka, Zambia over a 30-month period. Clinical outcomes will be assessed via surveys with PLHIV accessing routine HIV services, and a prospective cohort of PLHIV with cardiometabolic comorbidities nested within the larger trial. We will also collect data using mixed methods, including in-depth interviews, questionnaires, focus group discussions, and structured observations, and estimate cost-effectiveness through time-and-motion studies and other costing methods, to understand implementation outcomes according to Proctor's Outcomes for Implementation Research, the Consolidated Framework for Implementation Research, and selected dimensions of RE-AIM. DISCUSSION: Findings from this study will be used to make discrete, actionable, and context-specific recommendations in Zambia and the region for integrating cardiometabolic NCD care into national HIV treatment programs. While the TASKPEN study focuses on cardiometabolic NCDs in PLHIV, the multifaceted implementation strategy studied will be relevant to other NCDs and to people without HIV. It is expected that the trial will generate new insights that enable delivery of high-quality integrated HIV-NCD care, which may improve cardiovascular morbidity and viral suppression for PLHIV in SSA. This study was registered at ClinicalTrials.gov (NCT05950919).
Faecal Coliforms and Escherichia coli Contamination in Drinking Water Sources in Cholera Hotspot Areas of Lusaka District, Zambia: A Cross-Sectional Study
(Microorganisms, 2026-02-11) Ng’ombe, Harriet; Luchen, Charlie C.; Phiri, Bernard; Ngosa, Dennis; Kapikila, Robby; Sakanya, Sydney; Sakala, Chikondi; Mbewe, Nyuma; Liswaniso, Fraser; Chilengi, Roma; Wilkinson, Eduan; Liebenberg, Lenine; Khan, Wesaal; Thomson, Nicholas R; Sack, David; Bosomprah, Samuel; Chisenga, Caroline C.
Abstract The October 2023 to 2024 cholera outbreak demonstrates significant challenges related to water quality and sanitation, especially in peri-urban areas with limited access to clean water. This study assesses the presence of faecal coliforms and Escherichia coli (E. coli) in drinking water sources across five townships, identified as cholera transmission hotspots, two months post the cholera outbreak in the Lusaka District. A total of 169 water samples were collected from protected sources, treated piped water, and unprotected sources, including dams and shallow wells. Faecal coliforms and E. coli were detected across all source types. Among unprotected sources, 92.3% (12/13) of samples contained ≥100 CFU/100 mL of both faecal coliforms and E. coli. Protected sources showed variable contamination, with 18.3% exceeding ≥100 CFU/100 mL for faecal coliforms and 15.4% for E. coli. Treated water sources showed the lowest contamination, with 88.5% of samples having no detectable faecal coliforms and 90.4% having no detectable E. coli. Zero-inflated negative binomial regression showed that treated water sources were associated with substantially lower faecal coliform counts compared with protected sources (PR = 0.11, 95% CI: 0.03–0.35), while unprotected sources exhibited higher contamination intensity (PR = 1.77, 95% CI: 0.94–3.31). Treated sources were significantly more likely to be structurally free of contamination, whereas unprotected sources had an extremely low probability of yielding zero counts. These findings indicate that current water safety conditions in Lusaka’s cholera hotspot areas remain inadequate for preventing faecal-oral transmission.
Genomic Analysis and Antimicrobial Resistance of Vibrio Cholerae Isolated During Zambia’s 2023 Cholera Epidemic
(2025-12-02) Ng'ombe, Harriet; Luchen, Charlie C.; Bote, Lia; Kasonde, Mpanga; Musonda, Kunda; Mwape, Kapambwe K.; Kuntawala, Dhvani H.; Silwamba, Suwilanji; Chibuye, Mwelwa; Chibesa, Kennedy; Mbewe, Nyuma; Bosomprah, Samuel; Khan, Wesaal; Liebenberg, Lenine; Oliveira, Tulio de; Wilkinson, Eduan; Dorman, Matthew J.; Coghlan, Avril; Simuyandi, Michelo; Chilengi, Roma; Chisenga, Caroline C.; Thomson, Nicholas R.
Introduction. Cholera, caused by Vibrio cholerae, remains a priority public health concern, particularly in developing countries. The first cholera outbreak in Zambia was documented in the 1970s, with recurring epidemics reported since then. In 2023, a cholera outbreak affected Zambia, particularly in districts bordering Malawi, Mozambique and the Democratic Republic of Congo, with significant cases reported in these neighbouring countries. This study aims to analyse cholera cases and isolates obtained during the 2023 epidemic, focusing on geographical distribution, genetic relatedness of isolates and their antibiotic resistance profiles. Methods. Stool samples were collected from patients presenting with cholera-like symptoms across three provinces of Zambia. A total of 98 samples were cultured on thiosulphate citrate bile salts sucrose agar, resulting in 32 sequenced V. cholerae isolates. Whole-genome sequencing was performed using Oxford Nanopore Technology, and phylogenetic inference was also achieved by the analysis of SNPs. Phenotypic antimicrobial resistance testing was conducted following Clinical and Laboratory Standards Institute guidelines. The genomic data were analysed for virulence factors and antimicrobial resistance profiles. Results. Of the 98 stool samples tested, 38 confirmed cholera cases were identified. A subset of 32 confirmed V. cholerae isolates, predominantly from the Eastern Province of Zambia (n=21), was selected for whole-genome sequencing. Genomic analysis revealed that all isolates belonged to the seventh pandemic El Tor lineage and the O1 serogroup, with two distinct clades identified corresponding to the 10th (T10) and 15th (T15) transmission events. Geographical analysis indicated a predominance of Ogawa serotypes in Eastern Province and Inaba in Northern Province. The virulence gene analysis confirmed the presence of key cholera toxin genes (ctxA and ctxB) and intestinal colonization factors. All isolates carried genes or mutations predicted to confer resistance to multiple antibiotics, including decreased susceptibility to ciprofloxacin, recommended for the treatment of cholera by the World Health Organization. Conclusion. The findings highlight the critical need for enhanced surveillance and targeted interventions to mitigate cholera outbreaks in Zambia. The emergence of resistant V. cholerae strains necessitates innovative strategies, including improved water sanitation, vaccination efforts and novel therapeutic approaches to combat this enduring public health threat.
Immunogenicity and waning immunity from the oral cholera vaccine (Shanchol™) in adults residing in Lukanga Swamps of Zambia.
(2022) Ng Ombe, Harriet; Simuyandi, Michelo; Mwaba, John; Luchen, Charlie C.; Alabi, Peter; Chilyabanyama, Obvious N.; Mubanga, Cynthia; Hatyoka, Luiza M.; Muchimba, Mutinta; Bosomprah, Samuel; Chilengi, Roma; Kwenda, Geoffrey; Chisenga, Caroline C.
INTRODUCTION: In cholera endemic areas, the periodicity of cholera outbreaks remains unpredictable, making it difficult to organize preventive efforts. Lack of data on duration of protection conferred by oral cholera vaccines further makes it difficult to determine when to deploy preemptive vaccination. We report on the immunogenicity and waning of immunity to Shanchol™ in Lukanga Swamps. METHODS: We enrolled a cohort of 223 participants aged between 18 and 65 years old from whom serum samples were collected at baseline, day 28 before administration of the second dose, and consecutively at 6, 12, 24, 30, 36, and 48 months. Vibriocidal antibody titres were measured and expressed as geometric mean titres. Box plots and 95% CI were computed at each visit for both Inaba and Ogawa. Seroconversion was defined as a four fold or greater increase in antibody titres compared to baseline titres. RESULTS: Overall, seroconversion against V. cholerae Inaba and Ogawa after 1st dose was 35/134 (26%) and 34/134 (25%) respectively. We observed a statistical difference in seroconversion between the two subgroups of baseline titres (low <80 and high ≥80) for both Inaba (p = 0.02) and Ogawa (p<0.0001). From a baseline of 13.58, anti-Ogawa GMT increased to 21.95 after the first dose, but rapidly waned to 14.52, 13.13, and 12.78 at months 6, 12 and 24 respectively, and then increased to 13.21, 18.67 and 23.65 at months 30, 36 and 48 respectively. A similar trend was observed for anti-Inaba GMT across the same time points. CONCLUSION: We found that Shanchol™ was immunogenic in our study population and that vibriocidal antibodies may not be a good marker for long-term immunity. The observed rise in titres after 36 months suggests natural exposure, and this may be a critical time window opening for natural transmission in an endemic areas. We recommend re-vaccination at this time point in high risk areas.
Immunogenicity of rotavirus vaccine (RotarixTM) in infants with environmental enteric dysfunction.
(2017) Mwape, Innocent; Bosomprah, Samuel; Mwaba, John; Mwila-Kazimbaya, Katayi; Laban, Natasha M.; Chisenga, Caroline C.; Sijumbila, Gibson; Simuyandi, Michelo; Chilengi, Roma
INTRODUCTION: Deployment of rotavirus vaccines has contributed to significant declines in diarrheal morbidity and mortality globally. Unfortunately, vaccine performance in low-middle income countries (LMICs) is generally lower than in developed countries. The cause for this has been associated with several host and maternal factors including poor water sanitation and hygiene (WASH) status, which are predominant in LMICs. More recently, environmental enteric dysfunction (EED) has specifically been hypothesized to contribute to poor vaccine uptake and response. The aim of this study was to examine the association between serological biomarkers of EED and seroconversion to rotavirus vaccine in Zambian infants. METHODS: This was a retrospective cohort study of 142 infants who had been fully immunized with Rotarix™, and had known seroconversion status. Seroconversion was defined as 4-fold or more increase in rotavirus-specific IgA titres between pre-vaccination and one month post-dose two vaccination. We performed ELISA assays to assess soluble CD14 (sCD14), Endotoxin Core IgG Antibodies (EndoCAb), intestinal fatty acid binding protein (i-FABP) and Zonulin according to the manufacturers protocols. Generalised linear model with family-poisson, link-log and robust standard error was used to estimate the independent effects of biomarkers on seroconversion adjusting for important cofounders. RESULTS: The median concentration of Zonulin, Soluble CD14, EndoCaB, and IFABP were 209.3 (IQR = 39.7, 395.1), 21.5 (IQR = 21.5, 21.5), 0.3 (IQR = 0.3, 0.3), and 107.7 (IQR = 6.4, 1141.4) respectively. In multivariable analyses adjusting for the independent effect of other biomarkers and confounders (i.e. age of child at vaccination, breast-milk anti-rotavirus IgA, infant serum anti-rotavirus IgG, and IgA seropositivity at baseline), there was strong evidence of about 24% increase in seroconversion due to doubling Zonulin concentration (Adjusted risk ratio (aRR) = 1.24; 95% CI = 1.12 to1.37; p<0.0001). Similarly, we found about 7% increase in seroconversion due to doubling IFABP concentration (aRR = 1.07; 95% CI = 1.02 to 1.13; p = 0.006). CONCLUSION: We found that high levels of zonulin and IFABP played a role in seroconversion. It is plausible that increased gut permeability in EED allows greater uptake of the live virus within the vaccine, but later consequences result in deleterious local structural distortions and malabsorption syndromes.
Impact of antibiotics on gut microbiome composition and resistome in the first years of life in low- to middle-income countries: A systematic review.
(2023-Jun) Luchen, Charlie C.; Chibuye, Mwelwa; Spijker, Rene; Simuyandi, Michelo; Chisenga, Caroline C.; Bosomprah, Samuel; Chilengi, Roma; Schultsz, Constance; Mende, Daniel R.; Harris, Vanessa C.
BACKGROUND: Inappropriate antimicrobial usage is a key driver of antimicrobial resistance (AMR). Low- and middle-income countries (LMICs) are disproportionately burdened by AMR and young children are especially vulnerable to infections with AMR-bearing pathogens. The impact of antibiotics on the microbiome, selection, persistence, and horizontal spread of AMR genes is insufficiently characterized and understood in children in LMICs. This systematic review aims to collate and evaluate the available literature describing the impact of antibiotics on the infant gut microbiome and resistome in LMICs. METHODS AND FINDINGS: In this systematic review, we searched the online databases MEDLINE (1946 to 28 January 2023), EMBASE (1947 to 28 January 2023), SCOPUS (1945 to 29 January 2023), WHO Global Index Medicus (searched up to 29 January 2023), and SciELO (searched up to 29 January 2023). A total of 4,369 articles were retrieved across the databases. Duplicates were removed resulting in 2,748 unique articles. Screening by title and abstract excluded 2,666 articles, 92 articles were assessed based on the full text, and 10 studies met the eligibility criteria that included human studies conducted in LMICs among children below the age of 2 that reported gut microbiome composition and/or resistome composition (AMR genes) following antibiotic usage. The included studies were all randomized control trials (RCTs) and were assessed for risk of bias using the Cochrane risk-of-bias for randomized studies tool. Overall, antibiotics reduced gut microbiome diversity and increased antibiotic-specific resistance gene abundance in antibiotic treatment groups as compared to the placebo. The most widely tested antibiotic was azithromycin that decreased the diversity of the gut microbiome and significantly increased macrolide resistance as early as 5 days posttreatment. A major limitation of this study was paucity of available studies that cover this subject area. Specifically, the range of antibiotics assessed did not include the most commonly used antibiotics in LMIC populations. CONCLUSION: In this study, we observed that antibiotics significantly reduce the diversity and alter the composition of the infant gut microbiome in LMICs, while concomitantly selecting for resistance genes whose persistence can last for months following treatment. Considerable heterogeneity in study methodology, timing and duration of sampling, and sequencing methodology in currently available research limit insights into antibiotic impacts on the microbiome and resistome in children in LMICs. More research is urgently needed to fill this gap in order to better understand whether antibiotic-driven reductions in microbiome diversity and selection of AMR genes place LMIC children at risk for adverse health outcomes, including infections with AMR-bearing pathogens.
Liver steatosis and metabolic dysfunction-associated fatty liver disease among HIV-positive and negative adults in urban Zambia.
(2022-Jul) Chihota, Belinda V.; Riebensahm, Carlotta; Muula, Guy; Sinkala, Edford; Chilengi, Roma; Mulenga, Lloyd; Bosomprah, Samuel; Vinikoor, Michael J.; Bolton-Moore, Carolyn; Egger, Matthias; Rauch, Andri; Berzigotti, Annalisa; Wandeler, Gilles
INTRODUCTION: The growing importance of non-communicable diseases (NCDs) and high HIV prevalence in urban African settings may increase the burden of metabolic dysfunction-associated fatty liver disease (MAFLD). We assessed liver steatosis among HIV-positive and negative adults in urban Zambia. METHODS: Adults 30 years and older who were newly diagnosed with HIV, or tested HIV-negative at two primary care clinics in Lusaka, Zambia, were assessed for liver steatosis. Cardiometabolic data were collected through comprehensive clinical and laboratory assessments. Transient elastography was performed to measure controlled-attenuation parameter (≥248 dB/m). We used multivariable logistic regression models to determine the factors associated with the presence of steatosis. RESULTS: We enrolled 381 patients, including 154 (40%) antiretroviral therapy-naïve people living with HIV (PLWH) with a median CD4+ count of 247 cells/mm CONCLUSIONS: The prevalence of liver steatosis in this urban cohort of HIV-positive and negative adults in Zambia was low, despite a large proportion of patients with high BMI and central obesity. Our study is among the first to report data on MAFLD among adults in Africa, demonstrating that metabolic risk factors are key drivers of liver steatosis and supporting the adoption of the criteria for MAFLD in African populations.
Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review.
(2021-Aug-10) Velu, Rachel M.; Kwenda, Geoffrey; Libonda, Liyali; Chisenga, Caroline C.; Flavien, Bumbangi N.; Chilyabanyama, Obvious N.; Simunyandi, Michelo; Bosomprah, Samuel; Sande, Nicholus C.; Changula, Katendi; Muleya, Walter; Mburu, Monicah M.; Mubemba, Benjamin; Chitanga, Simbarashe; Tembo, John; Bates, Matthew; Kapata, Nathan; Orba, Yasuko ; Kajihara, Masahiro; Takada, Ayato; Sawa, Hirofumi ; Chilengi, Roma; Simulundu, Edgar
Emerging and re-emerging mosquito-borne viral diseases are a threat to global health. This systematic review aimed to investigate the available evidence of mosquito-borne viral pathogens reported in Zambia. A search of literature was conducted in PubMed and Google Scholar for articles published from 1 January 1930 to 30 June 2020 using a combination of keywords. Eight mosquito-borne viruses belonging to three families,
Performance of Machine Learning Classifiers in Classifying Stunting among Under-Five Children in Zambia.
(2022-Jul-20) Chilyabanyama, Obvious N.; Chilengi, Roma; Simuyandi, Michelo; Chisenga, Caroline C.; Chirwa, Masuzyo; Hamusonde, Kalongo; Saroj, Rakesh K.; Iqbal, Najeeha T.; Ngaruye, Innocent ; Bosomprah, Samuel
Stunting is a global public health issue. We sought to train and evaluate machine learning (ML) classification algorithms on the Zambia Demographic Health Survey (ZDHS) dataset to predict stunting among children under the age of five in Zambia. We applied Logistic regression (LR), Random Forest (RF), SV classification (SVC), XG Boost (XgB) and Naïve Bayes (NB) algorithms to predict the probability of stunting among children under five years of age, on the 2018 ZDHS dataset. We calibrated predicted probabilities and plotted the calibration curves to compare model performance. We computed accuracy, recall, precision and F1 for each machine learning algorithm. About 2327 (34.2%) children were stunted. Thirteen of fifty-eight features were selected for inclusion in the model using random forest. Calibrating the predicted probabilities improved the performance of machine learning algorithms when evaluated using calibration curves. RF was the most accurate algorithm, with an accuracy score of 79% in the testing and 61.6% in the training data while Naïve Bayesian was the worst performing algorithm for predicting stunting among children under five in Zambia using the 2018 ZDHS dataset. ML models aids quick diagnosis of stunting and the timely development of interventions aimed at preventing stunting.