Browsing by Author "Savory, Theodora"

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Estimating potential silent transfer using baseline viral load measures among people presenting as new to HIV care in Lusaka, Zambia: a cross-sectional study.
(2023-May-25) Pry, Jake M.; Mwila, Chilambwe ; Kapesa, Herbert; Mulabe, Musunge; Frimpong, Christiana ; Moono, Misinzo; Savory, Theodora; Bolton-Moore, Carolyn; Herce, Michael E.; Iyer, Shilpa
OBJECTIVES: To estimate potential silent transfer using baseline viral load measures among individuals presenting as new to HIV care in routine HIV clinical settings in Lusaka, Zambia. DESIGN: Cross-sectional study. SETTING: Two large, urban government-operated health facilities supported by the Centre for Infectious Disease Research in Zambia. PARTICIPANTS: A total of 248 participants with an incident positive HIV rapid test. OUTCOME MEASURES: The primary outcome measure was HIV viral suppression at baseline (i.e., potential silent transfer), defined as having a viral load ≤1000 RNA copies(c)/mL at the time of initiating HIV care. We also examined viral suppression at ≤60 c/mL. METHODS: We surveyed and measured baseline HIV viral load as part of the national recent infection testing algorithm among people living with HIV (PLWH) presenting as new to care. Using mixed effects Poisson regression, we identified characteristics among PLWH associated with potential silent transfer. RESULTS: Among the 248 PLWH included, 63% were women with median age of 30, and 66 (27% (66/248)) had viral suppression at ≤1000 c/mL and 53 (21% (53/248)) at ≤60 c/mL thresholds, respectively. Participants aged 40+ years had a significantly higher adjusted prevalence of potential silent transfer (adjusted prevalence ratio (aPR): 2.10; 95% CI: 2.08, 2.13) compared with participants aged 18-24 years. Participants reporting no formal education had a significantly higher adjusted prevalence of potential silent transfer (aPR: 1.63; 95% CI: 1.52, 1.75) compared with those completing primary education. Among 57 potential silent transfers who completed a survey, 44 (77%) indicated having tested positive previously at ≥1 of 38 clinics in Zambia. CONCLUSIONS: The high proportion of PLWH with potential silent transfer points to clinic shopping and/or co-enrolment at multiple care sites simultaneously, suggesting an opportunity to improve care continuity at the time of HIV care entry.
Geospatial Patterns of Progress towards UNAIDS "95-95-95" Targets and Community Vulnerability in Zambia.
(2023-Apr-26) Cuadros, Diego F.; Chowdhury, Tuhin; Milali, Masabho; Citron, Daniel; Nyimbili, Sulani; Vlahakis, Natalie; Savory, Theodora; Mulenga, Lloyd; Sivile, Suilanji; Zyambo, Khozya; Bershteyn, Anna
In sub-Saharan Africa, HIV/AIDS remains a leading cause of death. The UNAIDS established the "95-95-95" targets to improve HIV care continuum outcomes. Using geospatial data from the Zambia Population-based HIV Impact Assessment (ZAMPHIA), this study aims to investigate geospatial patterns in the "95-95-95" indicators and individual-level determinants that impede HIV care continuum in vulnerable communities, providing insights into the factors associated with gaps. This study used data from the 2016 ZAMPHIA to investigate the geospatial distribution and individual-level determinants of engagement across the HIV care continuum in Zambia. Gaussian kernel interpolation and optimized hotspot analysis were used to identify geospatial patterns in the HIV care continuum, while geospatial k-means clustering was used to partition areas into clusters. The study also assessed healthcare availability, access, and social determinants of healthcare utilization. Multiple logistic regression models were used to examine the association between selected sociodemographic and behavioral covariates and the three main outcomes of study. Varied progress towards the "95-95-95" targets were observed in different regions of Zambia. Each "95" displayed a unique geographic pattern, independent of HIV prevalence, resulting in four distinct geographic clusters. Factors associated with gaps in the "95s" include younger age, male sex, and low wealth, with younger individuals having higher odds of not being on ART and having detectable viral loads. Our study revealed significant spatial heterogeneity in the HIV care continuum in Zambia, with different regions exhibiting unique geographic patterns and levels of performance in the "95-95-95" targets, highlighting the need for geospatial tailored interventions to address the specific needs of different subnational regions. These findings underscore the importance of addressing differential regional gaps in HIV diagnosis, enhancing community-level factors, and developing innovative strategies to improve local HIV care continuum outcomes.
Geospatial patterns of progress towards UNAIDS '95-95-95' targets and community vulnerability in Zambia: insights from population-based HIV impact assessments.
(2023-Oct) Cuadros, Diego F.; Chowdhury, Tuhin; Milali, Masabho; Citron, Daniel T.; Nyimbili, Sulani; Vlahakis, Natalie ; Savory, Theodora; Mulenga, Lloyd; Sivile, Suilanji; Zyambo, Khozya D.; Bershteyn, Anna
INTRODUCTION: In sub-Saharan Africa, HIV/AIDS remains a leading cause of death. The UNAIDS established the '95-95-95' targets to improve HIV care continuum outcomes. Using geospatial data from the Zambia Population-based HIV Impact Assessment (ZAMPHIA), this study aims to investigate geospatial patterns in the '95-95-95' indicators and individual-level determinants that impede HIV care continuum in vulnerable communities, providing insights into the factors associated with gaps. METHODS: This study used data from the 2016 ZAMPHIA to investigate the geospatial distribution and individual-level determinants of engagement across the HIV care continuum in Zambia. Gaussian kernel interpolation and optimised hotspot analysis were used to identify geospatial patterns in the HIV care continuum, while geospatial k-means clustering was used to partition areas into clusters. The study also assessed healthcare availability, access and social determinants of healthcare utilisation. Multiple logistic regression models were used to examine the association between selected sociodemographic and behavioural covariates and the three main outcomes of study. RESULTS: Varied progress towards the '95-95-95' targets were observed in different regions of Zambia. Each '95' displayed a unique geographical pattern, independent of HIV prevalence, resulting in four distinct geographical clusters. Factors associated with gaps in the '95s' include younger age, male sex, and low wealth, with younger individuals having higher odds of not being on antiretroviral therapy and having detectable viral loads. CONCLUSIONS: Our study revealed significant spatial heterogeneity in the HIV care continuum in Zambia, with different regions exhibiting unique geographical patterns and levels of performance in the '95-95-95' targets, highlighting the need for geospatial tailored interventions to address the specific needs of different subnational regions. These findings underscore the importance of addressing differential regional gaps in HIV diagnosis, enhancing community-level factors and developing innovative strategies to improve local HIV care continuum outcomes.
Implementing SARS-CoV-2 routine surveillance in antenatal care in Zambia, 2021-2022: best practices and lessons learned.
(2025-Feb-28) Tembo, Tannia ; Heilmann, Elizabeth; Kabamba, Bupe M.; Fwoloshi, Sombo; Kalenga, Kalubi; Chilambe, Felix; Siwinga, Mpanji; Rutagwera, Marie-Reine ; Musunse, Maximillian; Kangale, Chabu; Yingst, Samuel; Yadav, Ruchi; Savory, Theodora; Gutman, Julie R.; Sikazwe, Izukanji ; Mulenga, Lloyd B.; Bolton-Moore, Carolyn; Hines, Jonas Z.
BACKGROUND: In Zambia, the true extent of SARS-CoV-2 infections is unknown because initial surveillance focused on patients with symptoms or severe disease. Antenatal sentinel surveillance had not been used to assess infection trends. The ANC COVID-19 surveillance study sought to determine SARS-CoV-2 seroprevalence and COVID-19 vaccine uptake among pregnant women. We provide insight into the study implementation, challenges encountered, best practices, and lessons learned. METHODS: A repeated cross-sectional seroprevalence survey was implemented at 39 health facilities in four districts from September 2021 to September 2022. Pregnant women aged 15-49 years were enrolled at their first antenatal care visits. An electronic questionnaire gathered demographics and other COVID-19 related information from consenting participants. A dried blood sample was collected to detect IgG antibodies using a multiplex bead assay. Seropositive results were categorized as infection, infection and vaccination or infection based on anti-RBD and anti-nucleocapsid test results. Problems and their root causes were identified as they occurred. Practical problem-solving strategies were devised, implemented, and monitored to ensure that goals were accomplished. RESULTS: In the primary analysis, 7% of the 9,221 samples collected from participants were not tested because they were missing. COVID-19 vaccine uptake of 9,111 pregnant women was assessed. Approximately 64% of participants were cumulatively seropositive for SARS-CoV-2 antibodies. Seroprevalence increased from 27.8% in September 2021 to 56.6% in July 2022. We observed an increase in vaccine coverage (0.5-27%) over time. Women aged 40-49 years old, without education and with prior COVID-19 infection were associated with higher vaccine uptake. The Delta variant of COVID-19 and the reallocation of health facilities between two partners delayed surveillance activities and increased the cost of implementation (e.g., the purchase of additional calibration and validation kits and DBS cards). Protocol deviations were attributed to the lack of experience in conducting research but, the district RAs repeatedly trained health facility staff to enhance their research knowledge. CONCLUSIONS: Incorporating SARS-CoV-2 surveillance into routine antenatal care is feasible and potentially sustainable when existing health system infrastructure, human resources, and surveillance systems are leveraged. Yet, careful planning is needed to anticipate implementation challenges and ensure high-quality data collection.
Mitigating the effects of COVID-19 on HIV treatment and care in Lusaka, Zambia: a before-after cohort study using mixed effects regression.
(2022-Jan) Pry, Jake M.; Sikombe, Kombatende; Mody, Aaloke; Iyer, Shilpa; Mutale, Jacob; Vlahakis, Natalie; Savory, Theodora; Wa Mwanza, Mwanza; Mweebo, Keith; Mwila, Annie; Mwale, Consity; Mukumbwa-Mwenechanya, Mpande; Kerkhoff, Andrew D.; Sikazwe, Izukanji; Bolton-Moore, Carolyn; Mwamba, Daniel; Geng, Elvin H.; Herce, Michael E.
INTRODUCTION: The Zambian Ministry of Health (MoH) issued COVID-19 mitigation guidance for HIV care immediately after the first COVID-19 case was confirmed in Zambia on 18 March 2020. The Centre for Infectious Disease Research in Zambia implemented MoH guidance by: 1) extending antiretroviral therapy (ART) refill duration to 6 multi-month dispensation (6MMD) and 2) task-shifting communication and mobilisation of those in HIV care to collect their next ART refill early. We assessed the impact of COVID-19 mitigation guidance on HIV care 3 months before and after guidance implementation. METHODS: We reviewed all ART pharmacy visit data in the national HIV medical record for PLHIV in care having ≥1 visit between 1 January-30 June 2020 at 59 HIV care facilities in Lusaka Province, Zambia. We undertook a before-after evaluation using mixed-effects Poisson regression to examine predictors and marginal probability of early clinic return (pharmacy visit >7 days before next appointment), proportion of late visit (>7 days late for next appointment) and probability of receiving a 6MMD ART refill. RESULTS: A total of 101 371 individuals (64% female, median age 39) with 130 486 pharmacy visits were included in the analysis. We observed a significant increase in the adjusted prevalence ratio (4.63; 95% CI 4.45 to 4.82) of early return before compared with after guidance implementation. Receipt of 6MMD increased from a weekly mean of 47.9% (95% CI 46.6% to 49.2%) before to 73.4% (95% CI 72.0% to 74.9%) after guidance implementation. The proportion of late visits (8-89 days late) was significantly higher before (18.8%, 95% CI17.2%to20.2%) compared with after (15.1%, 95% CI13.8%to16.4%) guidance implementation . CONCLUSIONS: Timely issuance and implementation of COVID-19 mitigation guidance involving task-shifted patient communication and mobilisation alongside 6MMD significantly increased early return to ART clinic, potentially reducing interruptions in HIV care during a global public health emergency.
Patterns of engagement in care during clients' first 12 months after HIV treatment initiation in Zambia: a retrospective cohort analysis using routinely collected data.
(2025-Aug-11) Benade, Mariet; Maskew, Mhairi; Chilembo, Phillip; Mwansa, Mwansa W.; Savory, Theodora; Nichols, Brooke; Bolton, Carolyn; Mulenga, Lloyd B ; Sivile, Suilanji; Zyambo, Khozya D. ; Rosen, Sydney
BACKGROUND: The first year after HIV treatment initiation or re-initiation is the period of highest risk of a treatment interruption or disengagement, yet little is known about the timing, patterns and effects of interruptions in the early treatment period. METHODS: Using routinely collected electronic medical record data from 543 Zambian facilities from 2018 to 2023, we described patterns of engagement during the first year of HIV treatment. We defined engagement patterns for months 0-6 and months 7-12 after initiation or reinitiation as (1) continuous (attended all scheduled clinic and medication pickup visits as planned; (2) cyclical (attended ≥1 visits late >28 days but returned to and remained in care) or (3) disengaged (missed a scheduled visit by >28 days and had no evidence of return). RESULTS: Our sample population comprised 159 429 adult participants (61% female, median age 33). Of the 513 322 interactions observed ≤12 months after initiation, 53% occurred as planned, 22% were late ≤28 days late, 9% were >28 days late, and 17% were scheduled but never attended. In 0-6 months after initiation, 51% clients were continuously engaged, 12% cyclically engaged and 33% disengaged. Two-thirds of disengagers (21% of cohort) did not return after the initiation visit. During months 7-12, most clients who had been continuously engaged in months 0-6 (54%) remained continuous, while 18% moved to cyclical engagement. Among cyclical engagers in months 0-6, nearly half (47%) moved to being continuously engaged by month 12. Only 34% of the study population remained engaged continuously by the end of the 12-month period. CONCLUSIONS: Fewer than 60% of clients initiating antiretroviral therapy care between 2018 and 2022 at Zambian facilities remained continuously engaged at month 6 and 34% at month 12. Cyclical engagement and frequent interruptions should be accepted as the norm and models of service delivery designed to accommodate them.
Programme science in action: lessons from an observational study of HIV prevention programming for key populations in Lusaka, Zambia.
(2024-Jul) Sikazwe, Izukanji; Musheke, Maurice; Chiyenu, Kanema ; Ngosa, Benard; Pry, Jake M.; Mulubwa, Chama; Zimba, Martin; Sakala, Martin; Sakala, Mphatso; Somwe, Paul; Nyirenda, Goodwin; Savory, Theodora; Bolton, Carolyn; Herce, Michael E.
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.
Trends in SARS-CoV-2 seroprevalence among pregnant women attending first antenatal care visits in Zambia: A repeated cross-sectional survey, 2021-2022.
(2024) Heilmann, Elizabeth; Tembo, Tannia; Fwoloshi, Sombo; Kabamba, Bupe ; Chilambe, Felix; Kalenga, Kalubi; Siwingwa, Mpanji; Mulube, Conceptor; Seffren, Victoria; Bolton-Moore, Carolyn; Simwanza, John; Yingst, Samuel; Yadav, Ruchi ; Rogier, Eric; Auld, Andrew F.; Agolory, Simon; Kapina, Muzala; Gutman, Julie R.; Savory, Theodora; Kangale, Chabu; Mulenga, Lloyd B.; Sikazwe, Izukanji ; Hines, Jonas Z.
SARS-CoV-2 serosurveys help estimate the extent of transmission and guide the allocation of COVID-19 vaccines. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess exposure trends over time in Zambia. We conducted repeated cross-sectional SARS-CoV-2 seroprevalence surveys among pregnant women aged 15-49 years attending their first ANC visits in four districts of Zambia (two urban and two rural) during September 2021-September 2022. Serologic testing was done using a multiplex bead assay which detects IgG antibodies to the nucleocapsid protein and the spike protein receptor-binding domain (RBD). We calculated monthly SARS-CoV-2 seroprevalence by district. We also categorized seropositive results as infection alone, infection and vaccination, or vaccination alone based on anti-RBD and anti-nucleocapsid test results and self-reported COVID-19 vaccination status (vaccinated was having received ≥1 dose). Among 8,304 participants, 5,296 (63.8%) were cumulatively seropositive for SARS-CoV-2 antibodies from September 2021 through September 2022. SARS-CoV-2 seroprevalence primarily increased from September 2021 to September 2022 in three districts (Lusaka: 61.8-100.0%, Chongwe: 39.6-94.7%, Chipata: 56.5-95.0%), but in Chadiza, seroprevalence increased from 27.8% in September 2021 to 77.2% in April 2022 before gradually dropping to 56.6% in July 2022. Among 5,906 participants with a valid COVID-19 vaccination status, infection alone accounted for antibody responses in 77.7% (4,590) of participants. Most women attending ANC had evidence of prior SARS-CoV-2 infection and most SARS-CoV-2 seropositivity was infection-induced. Capturing COVID-19 vaccination status and using a multiplex bead assay with anti-nucleocapsid and anti-RBD targets facilitated distinguishing infection-induced versus vaccine-induced antibody responses during a period of increasing COVID-19 vaccine coverage in Zambia. Declining seroprevalence in Chadiza may indicate waning antibodies and a need for booster vaccines. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 antibody dynamics to inform near real-time public health responses.