Centre for Infectious Disease Research in Zambia
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Recent Submissions
Mixed methods approach to examining the implementation experience of a phone-based survey for a SARS-CoV-2 test-negative case-control study in California.
(2024) Fukui N; Li SS; DeGuzman J; Myers JF; Openshaw J; Sharma A; Watt J; Lewnard JA; Jain S; Andrejko KL; Pry JM
OBJECTIVE: To describe the implementation of a test-negative design case-control study in California during the Coronavirus Disease 2019 (COVID-19) pandemic.
STUDY DESIGN: Test-negative case-control study.
METHODS: Between February 24, 2021 - February 24, 2022, a team of 34 interviewers called 38,470 Californians, enrolling 1,885 that tested positive for SARS-CoV-2 (cases) and 1,871 testing negative for SARS-CoV-2 (controls) for 20-minute telephone survey. We estimated adjusted odds ratios for answering the phone and consenting to participate using mixed effects logistic regression. We used a web-based anonymous survey to compile interviewer experiences.
RESULTS: Cases had 1.29-fold (95% CI: 1.24-1.35) higher adjusted odds of answering the phone and 1.69-fold (1.56-1.83) higher adjusted odds of consenting to participate compared to controls. Calls placed from 4pm to 6pm had the highest adjusted odds of being answered. Some interviewers experienced mental wellness challenges interacting with participants with physical (e.g., food, shelter, etc.) and emotional (e.g., grief counseling) needs, and enduring verbal harassment from individuals called.
CONCLUSIONS: Calls placed during afternoon hours may optimize response rate when enrolling controls to a case-control study during a public health emergency response. Proactive check-ins and continual collection of interviewer experience(s) and may help maintain mental wellbeing of investigation workforce. Remaining adaptive to the dynamic needs of the investigation team is critical to a successful study, especially in emergent public health crises, like that represented by the COVID-19 pandemic.
An exploration of multi-level factors affecting routine linkage to HIV care in Zambia's PEPFAR-supported treatment program in the treat all era.
(2024) Chipungu J; Smith H; Mwamba C; Haambokoma M; Sharma A; Savory T; Musheke M; Pry J; Bolton C; Sikazwe I; Herce ME
Multiple steps from HIV diagnosis to treatment initiation and confirmed engagement with the health system are required for people living with HIV to establish full linkage to care in the modern treat all era. We undertook a qualitative study to gain an in-depth understanding of the impeding and enabling factors at each step of this linkage pathway. In-depth interviews were conducted with fifty-eight people living with HIV recruited from ten routine HIV care settings supported by the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) in Lusaka, Zambia. Using a semi-structured interview guide informed by an established conceptual framework for linkage to care, questions explored the reasons behind late, missed, and early linkage into HIV treatment, as well as factors influencing the decision to silently transfer to a different clinic after an HIV diagnosis. We identified previously established and intersecting barriers of internal and external HIV-related stigma, concerns about ART side effects, substance use, uncertainties for the future, and a perceived lack of partner and social support that impeded linkage to care at every step of the linkage pathway. However, we also uncovered newer themes specific to the current test and treat era related to the rapidity of ART initiation and insufficient patient-centered post-test counseling that appeared to exacerbate these well-known barriers, including callous health workers and limited time to process a new HIV diagnosis before treatment. Long travel distance to the clinic where they were diagnosed was the most common reason for silently transferring to another clinic for treatment. On the other hand, individual resilience, quality counseling, patient-centered health workers, and a supportive and empathetic social network mitigated these barriers. These findings highlight potential areas for strengthening linkage to care and addressing early treatment interruption and silent transfer in the test and treat era in Zambia.
Systematic review of associations between gut microbiome composition and stunting in under-five children.
(2024-May-23) Chibuye M; Mende DR; Spijker R; Simuyandi M; Luchen CC; Bosomprah S; Chilengi R; Schultsz C; Harris VC
Childhood stunting is associated with impaired cognitive development and increased risk of infections, morbidity, and mortality. The composition of the enteric microbiota may contribute to the pathogenesis of stunting. We systematically reviewed and synthesized data from studies using high-throughput genomic sequencing methods to characterize the gut microbiome in stunted versus non-stunted children under 5 years in LMICs. We included 14 studies from Asia, Africa, and South America. Most studies did not report any significant differences in the alpha diversity, while a significantly higher beta diversity was observed in stunted children in four out of seven studies that reported beta diversity. At the phylum level, inconsistent associations with stunting were observed for Bacillota, Pseudomonadota, and Bacteroidota phyla. No single genus was associated with stunted children across all 14 studies, and some associations were incongruent by specific genera. Nonetheless, stunting was associated with an abundance of pathobionts that could drive inflammation, such as Escherichia/Shigella and Campylobacter, and a reduction of butyrate producers, including Faecalibacterium, Megasphera, Blautia, and increased Ruminoccoccus. An abundance of taxa thought to originate in the oropharynx was also reported in duodenal and fecal samples of stunted children, while metabolic pathways, including purine and pyrimidine biosynthesis, vitamin B biosynthesis, and carbohydrate and amino acid degradation pathways, predicted linear growth. Current studies show that stunted children can have distinct microbial patterns compared to non-stunted children, which could contribute to the pathogenesis of stunting.
Prospective multicentre accuracy evaluation of the FUJIFILM SILVAMP TB LAM test for the diagnosis of tuberculosis in people living with HIV demonstrates lot-to-lot variability.
(2024) Székely R; Sossen B; Mukoka M; Muyoyeta M; Nakabugo E; Hella J; Nguyen HV; Ubolyam S; Chikamatsu K; Macé A; Vermeulen M; Centner CM; Nyangu S; Sanjase N; Sasamalo M; Dinh HT; Ngo TA; Manosuthi W; Jirajariyavej S; Mitarai S; Nguyen NV; Avihingsanon A; Reither K; Nakiyingi L; Kerkhoff AD; MacPherson P; Meintjes G; Denkinger CM; Ruhwald M
There is an urgent need for rapid, non-sputum point-of-care diagnostics to detect tuberculosis. This prospective trial in seven high tuberculosis burden countries evaluated the diagnostic accuracy of the point-of-care urine-based lipoarabinomannan assay FUJIFILM SILVAMP TB LAM (FujiLAM) among inpatients and outpatients living with HIV. Diagnostic performance of FujiLAM was assessed against a mycobacterial reference standard (sputum culture, blood culture, and Xpert Ultra from urine and sputum at enrollment, and additional sputum culture ≤7 days from enrollment), an extended mycobacterial reference standard (eMRS), and a composite reference standard including clinical evaluation. Of 1637 participants considered for the analysis, 296 (18%) were tuberculosis positive by eMRS. Median age was 40 years, median CD4 cell count was 369 cells/ul, and 52% were female. Overall FujiLAM sensitivity was 54·4% (95% CI: 48·7-60·0), overall specificity was 85·2% (83·2-87·0) against eMRS. Sensitivity and specificity estimates varied between sites, ranging from 26·5% (95% CI: 17·4%-38·0%) to 73·2% (60·4%-83·0%), and 75·0 (65·0%-82·9%) to 96·5 (92·1%-98·5%), respectively. Post-hoc exploratory analysis identified significant variability in the performance of the six FujiLAM lots used in this study. Lot variability limited interpretation of FujiLAM test performance. Although results with the current version of FujiLAM are too variable for clinical decision-making, the lipoarabinomannan biomarker still holds promise for tuberculosis diagnostics. The trial is registered at clinicaltrials.gov (NCT04089423).
Benzathine penicillin G stockouts and other barriers to documented syphilis treatment in pregnancy in Zambia.
(2024) Jones AV; Manasyan A; Xue Y; Kapesa H; Mwendafilumba K; Nalwamba L; Mzumara M; Mubiana-Mbewe M; Dionne JA
OBJECTIVE: The prevalence of syphilis in Zambia remains high and is a critical public health concern. The Zambian Ministry of Health recommends universal screening and same-day treatment for syphilis in pregnancy, yet the syphilis screening rate is low, and treatment is poorly documented. The goal of this study was to document syphilis treatment rates and associated factors among pregnant women in care in Zambia.
METHODS: This retrospective cohort study included pregnant women diagnosed with syphilis according to rapid plasma reagin (RPR) screening during routine antenatal care (ANC) in Lusaka, Zambia in 2018-2019. The main outcome of interest was lack of documented BPG treatment during pregnancy. Additional information about pregnancy and neonatal outcomes, partner referral for therapy, and facility level stockout data were included. Patient characteristics were compared by treatment status using Pearson Chi-Square Test and logistic regression models were created to estimate the association between individual level-factors, facility type, and lack of BPG treatment. A Cochran-Mantel-Haenszel test was used to evaluate facility-level data with significance set at p<0.05.
RESULTS: Among 1,231 pregnant women who screened positive for syphilis at clinic, 643 (52%) lacked documented antibiotic treatment at the facility. BPG was the only antibiotic used to treat syphilis in the cohort and 8% of sex partners had evidence of referral for therapy. Preterm delivery rates were higher in women without documented BPG (43% vs 32%; p = 0.003). In adjusted models, only calendar year and hospital facility type were associated with lack of treatment. At the facility level, annual syphilis screening rates ranged from 37-65% and most (7/10) clinics reported at least one stockout of BPG.
CONCLUSION: Treatment rates for syphilis in pregnancy in Zambia were low and BPG medication stockouts at the facility level were common. A consistent supply of BPG at all ANC facilities is needed to facilitate timely treatment and improve birth outcomes.