22 research outputs found
Record linkage to de-duplicate sex-worker registers at the sex-work clinics in Zimbabwe using supervised learning techniques
No full textA Research Report submitted to the Faculty of Health Sciences in partial fulfilment of the requirements for the degree of Master of Science (MSc) Epidemiology – Public Health Informatics, August 2021Background
The Centre for Sexual Health, HIV and AIDs Research Zimbabwe implements the national sex work program in Zimbabwe on behalf of the Ministry of Health and Child Care and the National AIDs Council since 2009. The program offers free clinical services to sex workers through the ‘Sisters with a voice’ clinics. Sex workers are registered into the link log register and demographic information is collected at first visit. No identification is required to confirm the identity of the sex worker during registration. Due to stigma and criminalisation of sex work, sex workers sometimes use pseudo names at registration which they are likely to forget on their next visit. This has led to duplication as clients are assigned a sisters’ number in chronological order but there is no unique identifier to uniquely identify sex workers as they are registering.
Aim
This study aimed to apply Naïve Bayes Classifier and Support Vector Machine as supervised machine learning approaches to match and de-duplicate records in the link log and demographic data sets for female sex workers registered at Sisters' clinics in Zimbabwe. This information is key in enumerating the number of unique individual sex workers that were registered at the clinic between 2017 and 2019. This would help the program to come up with improved monitoring, interventions, strengthen key health priorities, and inform policy and practice. Furthermore, the study also aimed to ascertain the accuracy rate of repeat visits by sex workers to the Sisters' clinics and develop an optimum framework using improved supervised machine learning techniques as alternatives to conventional probabilistic record linkage techniques.
Methods
The study applied the Python record linkage toolkit to pre-process, index and link the demographic and link log data sets. The study used 85% of the data for training the algorithms and 15% of the data for testing and validation. Support Vector Machine and Naïve Bayes Classifier algorithms were applied on the linked dataset and results of the matching were compared in terms of scalability, accuracy and F1 score. Performance evaluation and validation was done to measure the Precision, Recall, Accuracy and F1 score of the algorithms.
Results
The study results showed that Support Vector Machine performs better than Naïve Bayes Classifier in record linkage. This study managed to de-duplicate the data and ascertain rate of repeat visits, from the 40 507 sex workers who were registered in the demographic data between 2017 and 2019. Furthermore this study showed an 8% duplicate rate in the records suggesting that 8% of the clients had been to the clinic before. The Support Vector Machine and Naïve Bayes Classifier algorithms were fit on the test data and Support Vector Machine outperformed Naïve Bayes Classifier with a Precision of 95,5%, Recall of 1 and Accuracy of 99,9% and an F1 score of 0.9778 respectively.
Conclusion
The study results showed that Support Vector Machine performs better than Naïve Bayes Classifier in record linkage. The Precision and Accuracy for Support Vector Machine and Naïve Bayes Classifier was above 90%. The Support Vector Machine model could be implemented on the sex work program data routinely to de-duplicate data and get accurate statistics for reporting and contributing to the size estimation of sex workers. The proportion of male and transgender sex workers in the program data can be a proxy to estimating the number of male sex workers and transgender sex workers in Zimbabwe as there is a gap in program data for male sex workers and transgender sex workers. Although there was a limitation in sample size as records of clients registered before 2017 had missing data in the variables of interest so they could not be included in this analysis, the results show that there is a gap in programming for male sex workers and transgender sex workers. There is need to intensify efforts and capacitate community-based organisations to come up
with intervention programmes to increase the uptake of health services by male and transgender sex workers so that the country can achieve its 95-95-95 goal of having 95% people tested for HIV and knowing their status, 95% of the HIV positives on treatment and 95% of those on treatment being virally suppressed.PC202
A process evaluation for the HIV/AIDS project for the Mbekweni Area Development Programme
No full textIncludes bibliographical references (leaves 56-59).This dissertation is a process evaluation of Mbekweni Area Development Programme (MADP)'s HIV/AIDS project. The MADP is a programme that is implemented by World Vision South Africa. The aim of the process evaluation was to assess whether the HIV/AIDS project was implemented as intended. HIV/AIDS is a global problem, particularly prominent in South Africa. It has negatively affected families and communities resulting in increased social and economic burdens. The HIV/AIDS project at MADP uses prevention and care programmes to mitigate the impact of HIV/AIDS in targeted areas of Mbekweni. In order to achieve this aim, the project uses the following programme activities: home visitation, home-based care, life skills, material support and awareness campaigns. To conduct the process evaluation, programme records, interviews with three key informants and questionnaires with 35 programme staff were used to assess the programme?s implementation. Findings from the evaluation show that the programme activities are largely being implemented as intended by the organisation. The HIV/AIDS project is being delivered to the intended beneficiaries and all the activities are being implemented as intended by the organisation. However, to improve the effectiveness of the project a structure
Responses of gut morphology, serum biochemistry and quality of breast meat to water deprivation in broilers
No full textResponses of growth performance, gut morphology, blood biochemistry, and quality of breast meat to varying lengths of water deprivation were assessed. Ninety broilers were randomly allocated to water deprivation treatments, where water was either supplied ad libitum (0 h) or for 30 min at intervals of 6, 12, 18, and 24 h. Average daily feed intake (ADFI) and gain (ADG) were estimated weekly. Six birds from each treatment were randomly slaughtered. The duodenum, jejunum, and ileum were sectioned to determine gut morphology. Breast meat muscles (pectoralis major) were sampled to determine its physicochemical properties. There were linear decreases in ADG (P < 0.01) and ADFI (P < 0.05), crypt depth (P < 0.01) and crypt width (P < 0.05) in the jejunum, villus height (VH) (P < 0.01) and total mucosa thickness (P < 0.05) in the ileum, crude fat (P < 0.05), b*0 (yellowness at 0 h), a*24 (redness at 24 h), and L*24 (lightness at 24 h) (P < 0.01), and aspartate aminotransferase enzyme (P < 0.05) with increases in length of water deprivation. Positive quadratic responses of VH in the duodenum (P < 0.01) and jejunum (P < 0.05) were observed after 7.6 and 19.4 h of water deprivation, respectively. Severe water deprivation periods reduced growth performance, but induced positive growth of VH, suggesting that broilers may adapt to water stress. The appropriate length of water deprivation was 7.64 h.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Understanding early uptake of PrEP by female sex workers in Zimbabwe.
No full textFemale sex workers (FSW) are prioritised for increased access to pre-exposure prophylaxis (PrEP), although rates of uptake remain sub-optimal, particularly across Southern Africa. In the first two years of its availability in Zimbabwe, 37.1% of FSW in trial sites initiated PrEP and received at least one re-supply. We conducted a qualitative study on perceptions of PrEP among 19 early users selected from sites with varying rates of PrEP initiation. Narrative interviews examined the pathways taken by FSW from hearing about PrEP, through their decision to start taking it, and early experiences. FSW appreciated PrEP's introduction within familiar and trusted "friendly" services tailored for sex workers and valued positive encouragement from clinic staff and peers over negative influence from family members. They also found PrEP difficult to understand at first, and feared side effects and rare adverse complications described in information leaflets. While FSW identified individual strategies for remembering to take their medication, they also relied on structured peer adherence support, leading some FSW to actively promote the method to other FSW as "PrEP champions". Information on how early users experience a new prevention technology such as PrEP can inform design of interventions that leverage existing support structures and target key barriers
Changes in engagement in HIV prevention and care services among female sex workers during intensified community mobilization in 3 sites in Zimbabwe, 2011 to 2015.
No full textINTRODUCTION: 'Sisters with a Voice', Zimbabwe's nationally scaled comprehensive programme for female sex workers (FSWs), intensified community mobilization activities in three sites to increase protective behaviours and utilization of clinical services. We compare indicators among FSWs at the beginning and after implementation. METHODS: We used mixed methods to collect data at three sites: in-depth interviews (n = 22) in 2015, routine clinical data from 2010 to 2015, and two respondent driven sampling surveys in 2011 and 2015, in which participants completed an interviewer-administered questionnaire and provided a finger prick blood sample for HIV antibody testing. Estimates were weighted using RDS-1 and estimate convergence assessed in both years. We assessed differences in six indicators between 2011 and 2015 using logistic regression adjusted for age, duration in sex work and education. RESULTS: 870 FSWs were recruited from the three sites in 2011 and 915 in 2015. Using logistic regression to adjust for socio-demographic differences, we found higher estimates of the proportion of HIV-positive FSWs and HIV-positive FSWs who knew their status and reported being on ART in Mutare and Victoria Falls in 2015 compared to 2011. Reported condom use with clients did not differ by year; however, condom use with regular partners was higher in 2015 in Mutare and Hwange. Reported HIV testing in the last six months among HIV-negative FSWs was higher in 2015 across sites: for instance, in Victoria Falls it was 13.4% (95% CI 8.7% to 19.9%) in 2011 and 80.8% (95% CI 74.0 to 87.7) in 2015. FSWs described positive perceptions of the Sisters programme, ease of engaging with health services, and improved solidarity among peers. Programme data showed increases in service use by 2015 across all sites. CONCLUSIONS: Improvements in key HIV care engagement indicators were observed among FSWs in two sites and in testing and prevention indicators across the three sites after implementation of an intensified community mobilization intervention. Engagement with services for FSWs is critical for countries to reach 90-90-90 targets
Changes in engagement in HIV prevention and care services among female sex workers during intensified community mobilization in 3 sites in Zimbabwe, 2011-2015
No full textIntroduction - ‘Sisters with a Voice’, Zimbabwe’s nationally-scaled comprehensive program for female sex workers (FSWs), intensified community mobilisation activities in three sites to increase protective behaviors and utilization of clinical services. We compare indicators among FSWs at the beginning and after implementation. Methods – We used mixed methods to collect data at three sites: in-depth interviews (n=22) in 2015, routine clinical data from 2010 to 2015, and two respondent driven sampling surveys in 2011 and 2015, in which participants completed an interviewer-administered questionnaire and provided a finger prick blood sample for HIV antibody testing. Estimates were weighted using RDS-1 and estimate convergence assessed in both years. We assessed differences in six indicators between 2011 and 2015 using logistic regression adjusted for age, duration in sex work and education.Results - 870 FSWs were recruited from the three sites in 2011 and 915 in 2015. Using logistic regression to adjust for socio-demographic differences, we found differences in the estimates of the proportion of HIV positive FSWs and HIV positive FSWs who knew their status and reported being on ART in Mutare and Victoria Fallsbetween 2011 and 2015. Reported condom use with clients was similar at both time points; however, condom use with regular partners different in 2015 in Mutare and Hwange. Reported HIV testing in the last 6 months among HIV negative FSWs was different at all sites for instance in Victoria Falls it was 13.4% (95% CI 8.7 – 19.9%) in 2011 and 80.8% (95% CI 74.0-87.7) in 2015. FSWs described positive perceptions of the Sisters program, ease of engaging with health services, and improved solidarity among peers. Program data showed increases in services use by 2015 across all sites. Conclusion – Improvements in key HIV care engagement indicators were observed among FSWs in two sites and in testing and prevention indicators across the three sites after implementation of an intensified community mobilisation intervention. Engagement with services for FSWs is critical for countries to reach 90.90.90 targets.</p
Enhancing national prevention and treatment services for sex workers in Zimbabwe: a process evaluation of the SAPPH-IRe trial.
No full textTargeted HIV interventions for female sex workers (FSW) combine biomedical technologies, behavioural change and community mobilization with the aim of empowering FSW and improving prevention and treatment. Understanding how to deliver combined interventions most effectively in sub-Saharan Africa is critical to the HIV response. The Sisters' Antiretroviral Programme for Prevention of HIV: an Integrated Response (SAPPH-Ire) randomized controlled trial in Zimbabwe tested an intervention to improve FSW engagement with HIV services. After 2 years, results of the trial showed no significant difference between study arms in proportion of FSW with HIV viral load ≥1000 copies/ml as steep declines occurred in both. We present the results of a process evaluation aiming to track the intervention's implementation, assess its feasibility and accessibility, and situate trial results within the national HIV policy context. We conducted a mixed methods study using data from routine programme statistics, qualitative interviews with participants and respondent driven surveys. The intervention proved feasible to deliver and was acceptable to FSW and providers. Intervention clinics saw more new FSW (4082 vs 2754), performed over twice as many HIV tests (2606 vs 1151) and nearly double the number of women were diagnosed with HIV (1042 vs 546). Community mobilization meetings in intervention sites also attracted higher numbers. We identified some gaps in programme fidelity: offering pre-exposure prophylaxis took time to engage FSW, viral load monitoring was not performed, and ratio of peer educators to FSW was lower than intended. During the trial, reaching FSW with HIV testing and treatment became a national priority, leading to increasing attendance at both intervention and control clinics. Throughout Zimbabwe, antiretroviral therapy coverage improved and HIV-stigma declined. Zimbabwe's changing HIV policy context appeared to contribute to positive improvements across the HIV care continuum for all FSW over the course of the trial. More intense community-based interventions for FSW may be needed to make further gains
Strategies to Identify and Reach Young Women Who Sell Sex With HIV Prevention and Care Services: Lessons Learnt From the Implementation of DREAMS Services in Two Cities in Zimbabwe.
No full textBACKGROUND: Young women who sell sex (YWSS), are underserved by available HIV prevention and care services. The Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) Partnership aimed to reduce the risk of HIV acquisition among vulnerable populations of adolescent girls and young women, including YWSS, in 10 sub-Saharan African countries. We describe 2 methods, respondent-driven sampling (RDS) and peer outreach, used to refer YWSS for DREAMS services in Zimbabwe, and compare the characteristics and engagement of YWSS referred to these services by each method. We hypothesized that RDS would identify YWSS at higher risk of HIV and those who were less engaged with HIV prevention and care services than peer outreach. OBJECTIVE: We aimed to compare respondent-driven sampling and peer outreach in recruiting and referring high-risk populations for HIV prevention and care services. METHODS: We used RDS, a sampling method designed to reach a representative sample of the network of key populations, and peer outreach, a programmatic approach to identify, reach, and refer YWSS for DREAMS between April and July 2017, and January 2017 and July 2018, respectively, in 2 cities in Zimbabwe. For RDS, we conducted detailed mapping to understand sex work typology and geography, and then purposively selected 10 "seed" participants in each city to initiate RDS. For peer outreach, we initiated recruitment through 18 trained and age-matched peer educators using youth-tailored community mobilization. We described the characteristics and service engagement of YWSS who accessed DREAMS services by each referral approach and assessed the association of these characteristics with referral approach using the chi-square test. Analysis was performed with and without restricting the period when RDS took place. We estimated the relative incremental costs of recruiting YWSS using each strategy for referral to DREAMS services. RESULTS: Overall, 5386 and 1204 YWSS were referred for DREAMS services through peer outreach and RDS, respectively. YWSS referred through RDS were more likely to access DREAMS services compared to YWSS referred through peer outreach (501/1204, 41.6% vs 930/5386, 17.3%; P<.001). Regardless of referral approach, YWSS who accessed DREAMS had similar education levels, and a similar proportion tested HIV negative and reported not using a condom at the last sex act. A higher proportion of YWSS accessing DREAMS through RDS were aged 18-19 years (167/501, 33.3% vs 243/930, 26.1%; P=.004) and more likely to be aware of their HIV status (395/501, 78.8% vs 396/930, 42.6%; P<.001) compared to those accessing DREAMS services through peer outreach. The incremental cost per young woman who sells sex recruited was US 52.81 for RDS. CONCLUSIONS: Peer outreach and RDS approaches can reach and refer high-risk but different groups of YWSS for HIV services, and using both approaches will likely improve reach. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-DOI 10.1186/s12889-018-5085-6
The impact of the DREAMS partnership on HIV incidence among young women who sell sex in two Zimbabwean cities: results of a non-randomised study.
No full textINTRODUCTION: Young women who sell sex (YWSS) in Zimbabwe remain at high risk of HIV infection. Effective HIV prevention strategies are needed. Through support to access a combination of evidence-based interventions, including oral pre-exposure prophylaxis (PrEP), the Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) partnership aimed to reduce new HIV infections among adolescent girls and young women by 40% over 24 months. METHODS: Non-randomised 'plausibility' evaluation, powered to detect a 40% HIV incidence difference between DREAMS and non-DREAMS sites. Two large cities with DREAMS funding were included, and four smaller non-DREAMS towns for comparison. In all sites, YWSS were enrolled to a cohort through peer-referral. Women were followed up for 24 months. HIV seroconversion was the primary outcome, with secondary outcomes identified through a theory of change. Outcomes were compared between YWSS recruited in DREAMS cities and non-DREAMS towns, adjusting for individual-level confounders and HIV prevalence at enrolment. RESULTS: From April to July 2017, 2431 women were enrolled, 1859 of whom were HIV negative at enrolment; 1019 of these women (54.8%) were followed up from March to May 2019 and included in endline analysis. Access to clinical services increased, but access to socioeconomic interventions promoted by DREAMS was limited. A total of 79 YWSS HIV seroconverted, with HIV incidence among YWSS in DREAMS cities lower (3.1/100 person-years) than in non-DREAMS towns (5.3/100 person-years). In prespecified adjusted analysis, HIV incidence was lower in DREAMS cities but with weak statistical evidence (adjusted rate ratio (RR)=0.68; 95% CI 0.40 to 1.19; p=0.18). Women in DREAMS cities were more likely to report ever and ongoing PrEP use, consistent condom use, fewer sexual partners and less intimate partner violence. CONCLUSION: It is plausible that DREAMS lowered HIV incidence among YWSS in two Zimbabwean cities, but our evaluation provides weak statistical evidence for impact and suggests any reduction in incidence was lower than the anticipated 40% decline. We identified changes to some important 'pathways to impact' variables, including condom use
Temporal trends in, and risk factors for, HIV seroconversion among female sex workers accessing Zimbabwe's national sex worker programme, 2009–19: a retrospective cohort analysis of routinely collected HIV testing data
No full textBACKGROUND: The frequency of new HIV infections among female sex workers in sub-Saharan Africa is poorly understood. We used routinely collected data that enable unique identification of repeat HIV testers to assess temporal trends in seroconversion and identify associated risk factors for female sex workers accessing Sisters with a Voice, Zimbabwe's national sex worker programme. METHODS: We pooled HIV testing data gathered between Sept 15, 2009, and Dec 31, 2019, from 36 Sisters programme sites in Zimbabwe. We included female sex workers aged 16 years or older with an HIV-negative test and at least one subsequent programme test. We calculated HIV seroconversion rates (using the midpoint between the HIV-positive test and the last negative test as the seroconversion date) and estimated rate ratios to compare 2-year periods by using Poisson regression, with robust SEs to account for clustering by site and adjusting for age and testing frequency to assess temporal trends. We did sensitivity analyses to explore assumptions about seroconversion dates and the effects of variation in follow-up time on our conclusions. FINDINGS: Our analysis included data for 6665 female sex workers, 441 (7%) of whom seroconverted. The overall seroconversion rate was 3·8 (95% CI 3·4-4·2) per 100 person-years at risk. Seroconversion rates fell with time since first negative HIV test. After adjustment, there was evidence of a decrease in seroconversion rates from 2009 to 2019 (p=0·0053). In adjusted analyses, being younger than 25 years, and having a sexually transmitted infection diagnosis at a previous visit, were significantly associated with increased seroconversion rates. Our findings were mostly robust to sensitivity analyses, but when 1 month before an HIV-positive test was used as the seroconversion date, seroconversion rates no longer fell with time. INTERPRETATION: We identified high rates of seroconversion shortly after linkage to programme services, which emphasises the need to strengthen HIV prevention programmes from first contact with female sex workers in Zimbabwe. New infections among female sex workers remain challenging to measure, but longitudinal analysis of routine testing data can provide valuable insights into seroconversion rates and associated risk factors. FUNDING: UN Population Fund, Deutsche Gesellschaft für Internationale Zusammenarbeit, the Bill & Melinda Gates Foundation, The Global Fund to Fight AIDS, Tuberculosis and Malaria, US President's Emergency Plan for AIDS Relief, US Agency for International Development, and the Elton John AIDS Foundation
