Journal Article > ResearchFull Text
Public Health Action. 2019 December 21
Nyagadza B, Kudya N, Mbofana E, Masaka S, Garone DB, et al.
Public Health Action. 2019 December 21
Background: Demand for viral load (VL) monitoring is expected to increase; however, implementation of the multifaceted VL testing poses numerous challenges. We report experiences from Médecins Sans Frontiéres (MSF) and partners in the scale-up of HIV VL in collaboration with the Ministry of Health and Child Care (MoHCC) of Zimbabwe.
Methods: A retrospective data review of routine reports from MSF-supported health facilities in Manicaland Province (Zimbabwe) was conducted. These secondary aggregate data were triangulated, and emerging themes of lessons learnt from VL monitoring were shared.
Results: A VL testing coverage of 63% (5966/9456) was achieved among the 40 health facilities, together with a switch rate to second-line antiretroviral therapy (ART) of 46.4% (108/233). The key enablers to scaling-up the VL monitoring were well-equipped and supported VL laboratories, the operationalisation of the on-the-job clinical mentoring and systematic weaning off of better performing health facilities. Concerted efforts from different implementing partners and funders in the HIV programme, and close collaboration with MoHCC were pivotal.
Conclusion: Our experience indicates that clinical mentoring is effective, and resulted in high VL testing coverage and up-skilling primary health care workers in VL monitoring. Attention must be focused on innovations for improving VL result utilisation, especially the identification and management of patients who fail ART.
Methods: A retrospective data review of routine reports from MSF-supported health facilities in Manicaland Province (Zimbabwe) was conducted. These secondary aggregate data were triangulated, and emerging themes of lessons learnt from VL monitoring were shared.
Results: A VL testing coverage of 63% (5966/9456) was achieved among the 40 health facilities, together with a switch rate to second-line antiretroviral therapy (ART) of 46.4% (108/233). The key enablers to scaling-up the VL monitoring were well-equipped and supported VL laboratories, the operationalisation of the on-the-job clinical mentoring and systematic weaning off of better performing health facilities. Concerted efforts from different implementing partners and funders in the HIV programme, and close collaboration with MoHCC were pivotal.
Conclusion: Our experience indicates that clinical mentoring is effective, and resulted in high VL testing coverage and up-skilling primary health care workers in VL monitoring. Attention must be focused on innovations for improving VL result utilisation, especially the identification and management of patients who fail ART.
Journal Article > ResearchFull Text
PLOS One. 2014 December 8; Volume 9 (Issue 12); DOI:10.1371/journal.pone.0114702
Polonsky JA, Martinez-Pino I, Nackers F, Chonzi P, Manangazira P, et al.
PLOS One. 2014 December 8; Volume 9 (Issue 12); DOI:10.1371/journal.pone.0114702
Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare.
Journal Article > ResearchFull Text
Vaccine. 2022 June 9; Volume S0264-410X (Issue 22); 00552-7.; DOI:10.1016/j.vaccine.2022.04.093
Lightowler M, Manangazira P, Nackers F, Van Herp M, Phiri I, et al.
Vaccine. 2022 June 9; Volume S0264-410X (Issue 22); 00552-7.; DOI:10.1016/j.vaccine.2022.04.093
BACKGROUND
Zimbabwe suffers from regular outbreaks of typhoid fever (TF), worse since 2017. Most cases were in Harare and a vaccination campaign with Typhoid Conjugate Vaccine (TCV) was conducted in March 2019. The vaccine effectiveness (VE) was assessed against culture-confirmed S. Typhi in children six months to 15 years and in individuals six months to 45 years in Harare.
METHODS
A matched case-control study was conducted in three urban suburbs of Harare targeted by the TCV vaccination campaign. Suspected TF cases were enrolled prospectively in four health facilities and were matched to facility (1:1) and community (1:5) controls.
FINDINGS
Of 504 suspected cases from July 2019 to March 2020, 148 laboratory-confirmed TF cases and 153 controls confirmed-negative were identified. One hundred and five (47 aged six months to 15 years) cases were age, sex, and residence matched with 105 facility-based controls while 96 cases were matched 1:5 by age, sex, and immediate-neighbour with 229 community controls.
The adjusted VE against confirmed TF was 75% (95%CI: 1–94, p = 0.049) compared to facility controls, and 84% (95%CI: 57–94, p < 0.001) compared to community controls in individuals six months to 15 years. The adjusted VE against confirmed TF was 46% (95%CI: 26–77, p = 0.153) compared to facility controls, and 67% (95%CI: 35–83, p = 0.002) compared to community controls six months to 45 years old.
INTERPRETATION
This study confirms that one vaccine dose of TCV is effective to control TF in children between six months and 15 years old in an African setting.
Zimbabwe suffers from regular outbreaks of typhoid fever (TF), worse since 2017. Most cases were in Harare and a vaccination campaign with Typhoid Conjugate Vaccine (TCV) was conducted in March 2019. The vaccine effectiveness (VE) was assessed against culture-confirmed S. Typhi in children six months to 15 years and in individuals six months to 45 years in Harare.
METHODS
A matched case-control study was conducted in three urban suburbs of Harare targeted by the TCV vaccination campaign. Suspected TF cases were enrolled prospectively in four health facilities and were matched to facility (1:1) and community (1:5) controls.
FINDINGS
Of 504 suspected cases from July 2019 to March 2020, 148 laboratory-confirmed TF cases and 153 controls confirmed-negative were identified. One hundred and five (47 aged six months to 15 years) cases were age, sex, and residence matched with 105 facility-based controls while 96 cases were matched 1:5 by age, sex, and immediate-neighbour with 229 community controls.
The adjusted VE against confirmed TF was 75% (95%CI: 1–94, p = 0.049) compared to facility controls, and 84% (95%CI: 57–94, p < 0.001) compared to community controls in individuals six months to 15 years. The adjusted VE against confirmed TF was 46% (95%CI: 26–77, p = 0.153) compared to facility controls, and 67% (95%CI: 35–83, p = 0.002) compared to community controls six months to 45 years old.
INTERPRETATION
This study confirms that one vaccine dose of TCV is effective to control TF in children between six months and 15 years old in an African setting.
Protocol > Research Study
Fernandez MAL, Schomaker M, Mason PR, Fesselet JF, Baudot Y, et al.
2012 June 18
BACKGROUND
In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009.
METHODS
We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs.
RESULTS
This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%.
CONCLUSION
This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic.
In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009.
METHODS
We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs.
RESULTS
This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%.
CONCLUSION
This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic.
Journal Article > ResearchFull Text
Int J Infect Dis. 2022 September 1; Volume 122; 215-221.; DOI:10.1016/j.ijid.2022.05.039
Zheng Q, Luquero FJ, Ciglenecki I, Wamala JF, Abubakar A, et al.
Int J Infect Dis. 2022 September 1; Volume 122; 215-221.; DOI:10.1016/j.ijid.2022.05.039
BACKGROUND
Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology.
METHODS
From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics.
RESULTS
We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks.
CONCLUSIONS
This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.
Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology.
METHODS
From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics.
RESULTS
We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks.
CONCLUSIONS
This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.
Journal Article > ResearchAbstract
Trans R Soc Trop Med Hyg. 2010 November 13; Volume 105 (Issue 1); DOI:10.1016/j.trstmh.2010.10.001
Luque Fernandez MA, Mason PR, Gray H, Bauernfeind A, Maes P
Trans R Soc Trop Med Hyg. 2010 November 13; Volume 105 (Issue 1); DOI:10.1016/j.trstmh.2010.10.001
This ecological study describes the cholera epidemic in Harare during 2008-2009 and identifies patterns that may explain transmission. Rates ratios of cholera cases by suburb were calculated by a univariate regression Poisson model and then, through an Empirical Bayes modelling, smoothed rate ratios were estimated and represented geographically. Mbare and southwest suburbs of Harare presented higher rate ratios. Suburbs attack rates ranged from 1.2 (95% Cl = 0.7-1.6) cases per 1000 people in Tynwald to 90.3 (95% Cl = 82.8-98.2) in Hopley. The identification of this spatial pattern in the spread, characterised by low risk in low density residential housing, and a higher risk in high density south west suburbs and Mbare, could be used to advocate for improving water and sanitation conditions and specific preparedness measures in the most affected areas.
Journal Article > Meta-AnalysisFull Text
PLOS One. 2013 July 22; Volume 8 (Issue 7); e68995.; DOI:10.1371/journal.pone.0068995
Pillay P, Ford NP, Shubber Z, Ferrand RA
PLOS One. 2013 July 22; Volume 8 (Issue 7); e68995.; DOI:10.1371/journal.pone.0068995
INTRODUCTION
There is conflicting evidence and practice regarding the use of the non-nucleoside reverse transcriptase inhibitors (NNRTI) efavirenz (EFV) and nevirapine (NVP) in first-line antiretroviral therapy (ART).
METHODS
We systematically reviewed virological outcomes in HIV-1 infected, treatment-naive patients on regimens containing EFV versus NVP from randomised trials and observational cohort studies. Data sources include PubMed, Embase, the Cochrane Central Register of Controlled Trials and conference proceedings of the International AIDS Society, Conference on Retroviruses and Opportunistic Infections, between 1996 to May 2013. Relative risks (RR) and 95% confidence intervals were synthesized using random-effects meta-analysis. Heterogeneity was assessed using the I(2) statistic, and subgroup analyses performed to assess the potential influence of study design, duration of follow up, location, and tuberculosis treatment. Sensitivity analyses explored the potential influence of different dosages of NVP and different viral load thresholds.
RESULTS
Of 5011 citations retrieved, 38 reports of studies comprising 114 391 patients were included for review. EFV was significantly less likely than NVP to lead to virologic failure in both trials (RR 0.85 [0.73-0.99] I(2) = 0%) and observational studies (RR 0.65 [0.59-0.71] I(2) = 54%). EFV was more likely to achieve virologic success than NVP, though marginally significant, in both randomised controlled trials (RR 1.04 [1.00-1.08] I(2) = 0%) and observational studies (RR 1.06 [1.00-1.12] I(2) = 68%).
CONCLUSION
EFV-based first line ART is significantly less likely to lead to virologic failure compared to NVP-based ART. This finding supports the use of EFV as the preferred NNRTI in first-line treatment regimen for HIV treatment, particularly in resource limited settings.
There is conflicting evidence and practice regarding the use of the non-nucleoside reverse transcriptase inhibitors (NNRTI) efavirenz (EFV) and nevirapine (NVP) in first-line antiretroviral therapy (ART).
METHODS
We systematically reviewed virological outcomes in HIV-1 infected, treatment-naive patients on regimens containing EFV versus NVP from randomised trials and observational cohort studies. Data sources include PubMed, Embase, the Cochrane Central Register of Controlled Trials and conference proceedings of the International AIDS Society, Conference on Retroviruses and Opportunistic Infections, between 1996 to May 2013. Relative risks (RR) and 95% confidence intervals were synthesized using random-effects meta-analysis. Heterogeneity was assessed using the I(2) statistic, and subgroup analyses performed to assess the potential influence of study design, duration of follow up, location, and tuberculosis treatment. Sensitivity analyses explored the potential influence of different dosages of NVP and different viral load thresholds.
RESULTS
Of 5011 citations retrieved, 38 reports of studies comprising 114 391 patients were included for review. EFV was significantly less likely than NVP to lead to virologic failure in both trials (RR 0.85 [0.73-0.99] I(2) = 0%) and observational studies (RR 0.65 [0.59-0.71] I(2) = 54%). EFV was more likely to achieve virologic success than NVP, though marginally significant, in both randomised controlled trials (RR 1.04 [1.00-1.08] I(2) = 0%) and observational studies (RR 1.06 [1.00-1.12] I(2) = 68%).
CONCLUSION
EFV-based first line ART is significantly less likely to lead to virologic failure compared to NVP-based ART. This finding supports the use of EFV as the preferred NNRTI in first-line treatment regimen for HIV treatment, particularly in resource limited settings.
Journal Article > ResearchFull Text
Trans R Soc Trop Med Hyg. 2018 June 1; Volume 112 (Issue 6); DOI:10.1093/trstmh/try054
Timire C, Takarinda KC, Harries AD, Mutunzi H, Manyame-Murwira B, et al.
Trans R Soc Trop Med Hyg. 2018 June 1; Volume 112 (Issue 6); DOI:10.1093/trstmh/try054
In Zimbabwe, while the Xpert MTB/RIF assay is being used for diagnosing tuberculosis and rifampicin-resistance, re-treatment tuberculosis (TB) patients are still expected to have culture and drug sensitivity testing (CDST) performed at national reference laboratories for confirmation. The study aim was to document the Xpert MTB/RIF assay scale-up and assess how the CDST system functioned for re-treatment TB patients.
Journal Article > ResearchFull Text
BMJ Open. 2018 January 11; Volume 8 (Issue 1); DOI:10.1136/bmjopen-2017-017405
Ballif M, Zurcher K, Reid SE, Boulle AM, Fox MP, et al.
BMJ Open. 2018 January 11; Volume 8 (Issue 1); DOI:10.1136/bmjopen-2017-017405
Seasonal variations in tuberculosis diagnoses have been attributed to seasonal climatic changes and indoor crowding during colder winter months. We investigated trends in pulmonary tuberculosis (PTB) diagnosis at antiretroviral therapy (ART) programmes in Southern Africa.
Journal Article > CommentaryFull Text
Public Health Action. 2013 June 21; Volume 3 (Issue 2); DOI:10.5588/pha.13.0002
Mlilo N, Sandy C, Harries AD, Kumar AMV, Masuka N, et al.
Public Health Action. 2013 June 21; Volume 3 (Issue 2); DOI:10.5588/pha.13.0002