Browsing by Author "Chiyenu K"

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Active TB case finding in a high burden setting; comparison of community and facility-based strategies in Lusaka, Zambia.
(2020) Kagujje M; Chilukutu L; Somwe P; Mutale J; Chiyenu K; Lumpa M; Mwanza W; Muyoyeta M; Tuberculosis Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; Strategic Information Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: We conducted an implementation science study to increase TB case detection through a combination of interventions at health facility and community levels. We determined the impact of the study in terms of additional cases detected and notification rate and compared the yield of bacteriologically confirmed TB of facility based and community based case finding. METHODOLOGY: Over a period of 18 months, similar case finding activities were conducted at George health facility in Lusaka Zambia and its catchment community, an informal peri-urban settlement. Activities included awareness and demand creation activities, TB screening with digital chest x-ray or symptom screening, sputum evaluation using geneXpert MTB/RIF, TB diagnosis and linkage to treatment. RESULTS: A total of 18,194 individuals were screened of which 9,846 (54.1%) were screened at the facility and 8,348 (45.9%) were screened in the community. The total number of TB cases diagnosed during the intervention period were 1,026, compared to 759 in the pre-intervention period; an additional 267 TB cases were diagnosed. Of the 563 bacteriologically confirmed TB cases diagnosed under the study, 515/563 (91.5%) and 48/563 (8.5%) were identified at the facility and in the community respectively (P<0.0001). The TB notification rate increased from 246 per 100,000 population pre-intervention to 395 per 100,000 population in the last year of the intervention. CONCLUSIONS: Facility active case finding was more effective in detecting TB cases than community active case finding. Strengthening health systems to appropriately identify and evaluate patients for TB needs to be optimised in high burden settings. At a minimum, provider initiated TB symptom screening with completion of the TB screening and diagnostic cascade should be provided at the health facility in high burden settings. Community screening needs to be systematic and targeted at high risk groups and communities with access barriers.
Evaluating InferVision's Computer-Aided Detection (CAD) algorithm for Tuberculosis (TB) screening, Lusaka, Zambia.
(2025) Somwe P; Maimbolwa M; Chiyenu K; Lumpa M; Kagujje M; Muyoyeta M; Centre for Infectious Disease Research in Zambia (CIDRZ), Lusaka, Zambia.
The objective of this study was to evaluate the diagnostic performance of InferRead DR Chest for tuberculosis (TB) screening in a high HIV and TB burden setting. The study assessed the performance of InferRead DR Chest using anonymized chest X-ray images from an active TB case finding study in Lusaka, Zambia, for individuals aged 15 and older. The Xpert MTB/RIF or MTB culture was the composite reference standard. Performance was evaluated using the Area Under the Receiver Operating Characteristic Curve (AUC), and a binary classification point was selected where the sensitivity aligned with the WHO target product profile for TB screening tools. Of the 1,890 chest X-ray images that met the inclusion criteria, 91.5% of participants reported at least one TB symptom. The median age was 38 years (IQR: 29-47), and 1,186 (62.8%) were male. From the study sample, 449 participants (23.8%) reported a history of previous TB, and 704 (37.2%) were HIV positive. Among the analyzed images, 289 (15.3%) were classified as TB positive based on the composite reference standard test results. The overall area under the curve (AUC) was 0.81 (95% CI: 0.78-0.83). Among individuals with a history of previous TB and those who were HIV positive, the AUCs were 0.71 (95% CI: 0.63-0.79) and 0.77 (95% CI: 0.72-0.82), respectively. At a sensitivity of 90.3% (95% CI: 86.3%-93.5%), InferRead DR Chest achieved a specificity of 39.2% (95% CI: 36.8%-41.7%) at TB score cut point of 0.12. InferRead DR Chest had acceptable performance in our population. Additional training and piloting of InferRead DR Chest in this population is recommended.
Evaluating the costs of cholera illness and cost-effectiveness of a single dose oral vaccination campaign in Lusaka, Zambia.
(2019) Tembo T; Simuyandi M; Chiyenu K; Sharma A; Chilyabanyama ON; Mbwili-Muleya C; Mazaba ML; Chilengi R; Lusaka District Health Office/ Ministry of Health, Lusaka, Zambia.; Zambia National Public Health Institute, Lusaka, Zambia.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: In 2016, for the very first time, the Ministry of Health in Zambia implemented a reactive outbreak response to control the spread of cholera and vaccinated at-risk populations with a single dose of Shancol-an oral cholera vaccine (OCV). This study aimed to assess the costs of cholera illness and determine the cost-effectiveness of the 2016 vaccination campaign. METHODOLOGY: From April to June 2017, we conducted a retrospective cost and cost-effectiveness analysis in three peri-urban areas of Lusaka. To estimate costs of illness from a household perspective, a systematic random sample of 189 in-patients confirmed with V. cholera were identified from Cholera Treatment Centre registers and interviewed for out-of-pocket costs. Vaccine delivery and health systems costs were extracted from financial records at the District Health Office and health facilities. The cost of cholera treatment was derived by multiplying the subsidized cost of drugs by the quantity administered to patients during hospitalisation. The cost-effectiveness analysis measured incremental cost-effectiveness ratio-cost per case averted, cost per life saved and cost per DALY averted-for a single dose OCV. RESULTS: The mean cost per administered vaccine was US$1.72. Treatment costs per hospitalized episode were US$14.49-US$18.03 for patients ≤15 years old and US$17.66-US$35.16 for older patients. Whereas households incurred costs on non-medical items such as communication, beverages, food and transport during illness, a large proportion of medical costs were borne by the health system. Assuming vaccine effectiveness of 88.9% and 63%, a life expectancy of 62 years and Gross Domestic Product (GDP) per capita of US$1,500, the costs per case averted were estimated US$369-US$532. Costs per life year saved ranged from US$18,515-US$27,976. The total cost per DALY averted was estimated between US$698-US$1,006 for patients ≤15 years old and US$666-US$1,000 for older patients. CONCLUSION: Our study determined that reactive vaccination campaign with a single dose of Shancol for cholera control in densely populated areas of Lusaka was cost-effective.
Improving PrEP access for adolescent girls and young women: a descriptive analysis of community-based PrEP delivery in the DREAMS programme in Zambia.
(2025-Jul) Musheke M; Pry JM; Sikazwe I; Muyunda WJ; Chiyenu K; Siame CM; Khondowe WK; Mushiki B; Mwaba MM; Zulu P; Mwape F; Siamasuku B; Shula D; Mweemba MB; Kanene C; Phiri A; Herce ME; School of Medicine, University of California, Davis, California, USA.; Centre for Infectious Disease Research in Zambia (CIDRZ), Lusaka, Zambia.; Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA.; United States Agency for International Development, United States of America Embassy, Lusaka, Zambia.; Young Women Christian Association, Lusaka, Zambia.; Ministry of Health, Ndeke House, Lusaka, Zambia.
INTRODUCTION: Despite being at high risk of HIV acquisition, access to pre-exposure prophylaxis (PrEP) among adolescent girls and young women (AGYW) is low in Zambia because PrEP is traditionally delivered in clinical settings. We describe the effects of community centres supported by the Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe (DREAMS) initiative on PrEP outcomes in Zambia and examine factors associated with PrEP continuation. METHODS: We collected individual-level PrEP data for AGYW aged 15-24 years at risk of HIV acquisition and enrolled in DREAMS in seven districts of Zambia between August 2022 and August 2024. We used Pearson's Chi-squared test to examine differences in beneficiary characteristics between clients with a PrEP initiation visit and ≥ 2 PrEP visits (i.e. an initiation plus ≥ 1 return visit), and mixed effects Poisson regression modelling to estimate the association between DREAMS enrolment criteria and PrEP continuation (defined as ≥ 1 PrEP visit within 180 days of initiation). We also estimated the marginal probability of PrEP continuation by number of DREAMS enrolment criteria and used Kaplan-Meier methods to estimate the time to the first PrEP return visit by client age band. RESULTS: Between 11 August 2022 and 23 August 2024, 15,502 AGYW aged 15-24 years were screened for PrEP eligibility, of whom 15,072 (97.2%) initiated PrEP per national guidelines. Of those initiating PrEP, 9807 (65.1%) had sufficient follow-up time to allow for observation of a PrEP return visit. The proportion of AGYW who had ≥ 1 PrEP return visit within 180 days of initiation was 59.0% (n/N = 5706/9675). Across age bands, the percent probability of having a PrEP return visit within 180 days of initiation was highest among clients who reported ≥ 4 DREAMS enrolment criteria at 91.7% (95% CI: 70.7, 112.7%) for clients aged 15-19 years and 83.6% (95% CI: 61.1, 106.2%) for clients aged 20-24 years. Overall, 41.5% of clients had a first PrEP return visit between 21 and 42 days of PrEP initiation. CONCLUSIONS: The high number and proportion of AGYW initiated on PrEP suggests that decentralising PrEP services to DREAMS community centres has the potential to improve PrEP access among AGYW. Increasing HIV risk perception among AGYW may improve PrEP continuation.
Programme science in action: lessons from an observational study of HIV prevention programming for key populations in Lusaka, Zambia.
(2024-Jul) Sikazwe I; Musheke M; Chiyenu K; Ngosa B; Pry JM; Mulubwa C; Zimba M; Sakala M; Sakala M; Somwe P; Nyirenda G; Savory T; Bolton-Moore C; Herce ME; Department of Public Health Sciences, School of Medicine, University of California, Davis, California, USA.; Centre for Infectious Disease Research in Zambia (CIDRZ), Lusaka, Zambia.; Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA.; Division of Infectious Diseases, Department of Medicine, University of Alabama, Birmingham, Alabama, USA.; Tithandizeni Umoyo Network, Lusaka, Zambia.; Intersex Society of Zambia, Lusaka, Zambia.; Zambia Sex Workers Alliance, Lusaka, Zambia.
INTRODUCTION: Optimizing uptake of pre-exposure prophylaxis (PrEP) for individuals at risk of HIV acquisition has been challenging despite clear scientific evidence and normative guidelines, particularly for key populations (KPs) such as men who have sex with men (MSM), female sex workers (FSWs), transgender (TG) people and persons who inject drugs (PWID). Applying an iterative Programme Science cycle, building on the effective programme coverage framework, we describe the approach used by the Centre for Infectious Disease Research in Zambia (CIDRZ) to scale up PrEP delivery and address inequities in PrEP access for KP in Lusaka, Zambia. METHODS: In 2019, CIDRZ partnered with 10 local KP civil society organizations (CSOs) and the Ministry of Health (MOH) to offer HIV services within KP-designated community safe spaces. KP CSO partners led KP mobilization, managed safe spaces and delivered peer support; MOH organized clinicians and clinical commodities; and CIDRZ provided technical oversight. In December 2021, we introduced a community-based intervention focused on PrEP delivery in venues where KP socialize. We collected routine programme data from September 2019 to June 2023 using programme-specific tools and the national electronic health record. We estimated the before-after effects of our intervention on PrEP uptake, continuation and equity for KP using descriptive statistics and interrupted time series regression, and used mixed-effects regression to estimate marginal probabilities of PrEP continuity. RESULTS: Most (25,658) of the 38,307 (67.0%) Key Population Investment Fund beneficiaries were reached with HIV prevention services at community-based venues. In total, 23,527 (61.4%) received HIV testing services, with 15,508 (65.9%) testing HIV negative and found PrEP eligible, and 15,241 (98.3%) initiating PrEP. Across all programme quarters and KP types, PrEP uptake was >90%. After introducing venue-based PrEP delivery, PrEP uptake (98.7% after vs. 96.5% before, p < 0.001) and the number of initiations (p = 0.014) increased significantly. The proportion of KP with ≥1 PrEP continuation visit within 6 months of initiation was unchanged post-intervention (46.7%, 95% confidence interval [CI]: 45.7%, 47.6%) versus pre-intervention (47.2%, 95% CI: 45.4%, 49.1%). CONCLUSIONS: Applying Programme Science principles, we demonstrate how decentralizing HIV prevention services to KP venues and safe spaces in partnership with KP CSOs enabled successful community-based PrEP delivery beyond the reach of traditional facility-based services.