Journal Article > ResearchFull Text
medRxiv. 2024 January 20; DOI:10.1101/2024.01.18.24301453
Zeng C, Hernán MA, Trevisi L, Sauer S, Mitnick CD, et al.
medRxiv. 2024 January 20; DOI:10.1101/2024.01.18.24301453
RATIONALE
Treatment outcomes may be compromised among patients with multidrug- or rifampicin-resistant tuberculosis with additional fluoroquinolone resistance. Evidence is needed to inform optimal treatment for these patients.
OBJECTIVES
We compared the effectiveness of longer individualized regimens comprised of bedaquiline for 5 to 8 months, linezolid, and clofazimine to those reinforced with at least 1 third-tier drug and/or longer duration of bedaquiline.
METHODS
We emulated a target trial to compare the effectiveness of initiating and remaining on the core regimen to one of five regimens reinforced with (1) bedaquiline for ≥9 months, (2) bedaquiline for ≥9 months and delamanid, (3) imipenem, (4) a second-line injectable, or (5) delamanid and imipenem. We included patients in whom a fluoroquinolone was unlikely to be effective based on drug susceptibility testing and/or prior exposure. Our analysis consisted of cloning, censoring, and inverse-probability weighting to estimate the probability of successful treatment.
MEASUREMENTS AND MAIN RESULTS
Adjusted probabilities of successful treatment were high across regimens, ranging from 0.75 (95%CI:0.61, 0.89) to 0.84 (95%CI:0.76, 0.91). We found no substantial evidence that any of the reinforced regimens improved effectiveness of the core regimen, with ratios of treatment success ranging from 1.01 for regimens reinforced with bedaquiline ≥9 months (95%CI:0.79, 1.28) and bedaquiline ≥9 months plus delamanid (95%CI:0.81, 1.31) to 1.11 for regimens reinforced by a second-line injectable (95%CI:0.92, 1.39) and delamanid and imipenem (95%CI:0.90, 1.41).
CONCLUSIONS
High treatment success underscores the effectiveness of regimens comprised of bedaquiline, linezolid, and clofazimine, highlighting the need for expanded access to these drugs.
Journal Article > ResearchFull Text
medRxiv. 2019 August 17; DOI:10.1101/19003434
Funk S, Takahashi S, Hellewell J, Gadroen K, Carrion Martin AI, et al.
medRxiv. 2019 August 17; DOI:10.1101/19003434
The Katanga region in the Democratic Republic of Congo (DRC) has been struck by repeated epidemics of measles, with large outbreaks occurring in 2010–13 and 2015. In many of the affected health zones, reactive mass vaccination campaigns were conducted in response to the outbreaks. Here, we attempted to determine how effective the vaccination campaigns in 2015 were in curtailing the ongoing outbreak. We further sought to establish whether the risk of large measles outbreaks in different health zones could have been determined in advance to help prioritise areas for vaccination campaign and speed up the response. In doing so, we first attempted to identify factors that could have been used in 2015 to predict in which health zones the greatest outbreaks would occur. Administrative vaccination coverage was not a good predictor of the size of outbreaks in different health zones. Vaccination coverage derived from surveys, on the other hand, appeared to give more reliable estimates of health zones of low vaccination coverage and, consequently, large outbreaks. On a coarser geographical scale, the provinces most affected in 2015 could be predicted from the outbreak sizes in 2010–13. This, combined with the fact that the vast majority of reported cases were in under-5 year olds, would suggest that there are systematic issues of undervaccination. If this was to continue, outbreaks would be expected to continue to occur in the affected health zones at regular intervals, mostly concentrated in under-5 year olds. We further used a model of measles transmission to estimate the impact of the vaccination campaigns, by first fitting a model to the data including the campaigns and then re-running this without vaccination. We estimated the reactive campaigns to have reduced the size of the overall outbreak by approximately 21,000 (IQR: 16,000–27,000; 95% CI: 8300–38,000) cases. There was considerable heterogeneity in the impact of campaigns, with campaigns started earlier after the start of an outbreak being more impactful. Taken together, these findings suggest that while a strong routine vaccination regime remains the most effective means of measles control, it might be possible to improve the effectiveness of reactive campaigns by considering predictive factors to trigger a more targeted vaccination response.
Other > Pre-Print
medRxiv. 2022 February 21; DOI:10.1101/2022.02.17.22271070
Yakum MN, Funwie AD, Tsafack M, Ebaze LE, Ajong AB, et al.
medRxiv. 2022 February 21; DOI:10.1101/2022.02.17.22271070
OBJECTIVE
The objective of this study was to determine the validity of parent’s recall for immunization using the vaccination card as the reference in Yaounde-Cameroon.
SETTINGS
This study was a communitybased study in all the 6 health districts in Yaounde, Cameroon
PARTICIPANTS
The study targeting parents of children aged 0-59months who had their children’s vaccination cards. The immunization history of each child was taken based on both parent’s recall and vaccination card. Using the vaccination card as a reference, the sensitivity, specificity, positive predictive value and negative predictive value of parent’s recall were calculated. The degree of agreement and the kappa statistics between the two methods were calculated using R version 4.1.0 (2021-05-18).
RESULTS
A total of 529 households were visited and 87 eligible parents enrolled. Approximately 55.2% of the 27 children were girls and 53% of them were aged 12-59 months. In total, 94.25% of the participants enrolled were one of the biological parents of the children, with mothers making the majority 86.20% of participants. When combined for all vaccines, the sensitivity, specificity, positive predictive value, and negative predictive value of parent’s recall were 63%, 60%, 90%, and 23% respectively. The degree of agreement between the two sources was highest for BCG(94%) and lowest with Polio2(32%). Parent’s recall(94%) was most likely to correctly predict BCG vaccination status of a child than using the scars on the forarm(74%).
CONCLUSION
Our conclusion is that validity and reliability of parent’s recall vary a lot across different vaccines and parent’s recall is not very reliable for immunization status assessment in children. Parent’s recall is preferred for verifying BCG immunization to scars on the forarm. In general, we recommend that parent’s recall for routine immunization should be used only as a last resort or for BCG, and measles and Yellow Fever vaccines.
The objective of this study was to determine the validity of parent’s recall for immunization using the vaccination card as the reference in Yaounde-Cameroon.
SETTINGS
This study was a communitybased study in all the 6 health districts in Yaounde, Cameroon
PARTICIPANTS
The study targeting parents of children aged 0-59months who had their children’s vaccination cards. The immunization history of each child was taken based on both parent’s recall and vaccination card. Using the vaccination card as a reference, the sensitivity, specificity, positive predictive value and negative predictive value of parent’s recall were calculated. The degree of agreement and the kappa statistics between the two methods were calculated using R version 4.1.0 (2021-05-18).
RESULTS
A total of 529 households were visited and 87 eligible parents enrolled. Approximately 55.2% of the 27 children were girls and 53% of them were aged 12-59 months. In total, 94.25% of the participants enrolled were one of the biological parents of the children, with mothers making the majority 86.20% of participants. When combined for all vaccines, the sensitivity, specificity, positive predictive value, and negative predictive value of parent’s recall were 63%, 60%, 90%, and 23% respectively. The degree of agreement between the two sources was highest for BCG(94%) and lowest with Polio2(32%). Parent’s recall(94%) was most likely to correctly predict BCG vaccination status of a child than using the scars on the forarm(74%).
CONCLUSION
Our conclusion is that validity and reliability of parent’s recall vary a lot across different vaccines and parent’s recall is not very reliable for immunization status assessment in children. Parent’s recall is preferred for verifying BCG immunization to scars on the forarm. In general, we recommend that parent’s recall for routine immunization should be used only as a last resort or for BCG, and measles and Yellow Fever vaccines.
Other > Pre-Print
medRxiv. 2024 January 29; DOI:10.1101/2024.01.29.24301679
Guglielmetti L, Khan U, Velasquez GE, Gouillou M, Abubakirov A, et al.
medRxiv. 2024 January 29; DOI:10.1101/2024.01.29.24301679
BACKGROUND
After a history of poor treatments for rifampin-resistant tuberculosis (RR-TB), recent advances have resulted in shorter, more effective treatments. However, they are not available to everyone and have shortcomings, requiring additional treatment options.
METHODS
endTB is an international, open-label, Phase 3 non-inferiority, randomized, controlled clinical trial to compare five 9-month all-oral regimens including bedaquiline (B), delamanid (D), linezolid (L), levofloxacin (Lfx) or moxifloxacin (M), clofazimine (C) and pyrazinamide (Z), to the standard (control) for treatment of fluoroquinolone-susceptible RR-TB. Participants were randomized to 9BLMZ, 9BCLLfxZ, 9BDLLfxZ, 9DCLLfxZ, 9DCMZ and control using Bayesian response-adaptive randomization. The primary outcome was favorable outcome at week 73 defined by two negative sputum culture results or by favorable bacteriologic, clinical and radiologic evolution. The non-inferiority margin was 12 percentage points.
RESULTS
Of 754 randomized patients, 696 and 559 were included in the modified intention to treat (mITT) and per-protocol (PP) analyses, respectively. In mITT, the control had 80.7% favorable outcomes. Regimens 9BCLLfxZ [adjusted risk difference (aRD): 9.5% (95% confidence interval (CI), 0.4 to 18.6)], 9BLMZ [aRD: 8.8% (95%CI, -0.6 to 18.2)], and 9BDLLfxZ [3.9% (95%CI, -5.8 to 13.6)] were non-inferior in mITT and in PP. The proportion of participants experiencing grade 3 or higher adverse events was similar across the regimens. Grade 3 or higher hepatotoxicity occurred in 11.7% of the experimental regimens overall and in 7.1% of the control.
CONCLUSIONS
The endTB trial increases treatment options for RR-TB with three shortened, all-oral regimens that were non-inferior to a current well-performing standard of care.
ClinicalTrials.gov: NCT02754765
After a history of poor treatments for rifampin-resistant tuberculosis (RR-TB), recent advances have resulted in shorter, more effective treatments. However, they are not available to everyone and have shortcomings, requiring additional treatment options.
METHODS
endTB is an international, open-label, Phase 3 non-inferiority, randomized, controlled clinical trial to compare five 9-month all-oral regimens including bedaquiline (B), delamanid (D), linezolid (L), levofloxacin (Lfx) or moxifloxacin (M), clofazimine (C) and pyrazinamide (Z), to the standard (control) for treatment of fluoroquinolone-susceptible RR-TB. Participants were randomized to 9BLMZ, 9BCLLfxZ, 9BDLLfxZ, 9DCLLfxZ, 9DCMZ and control using Bayesian response-adaptive randomization. The primary outcome was favorable outcome at week 73 defined by two negative sputum culture results or by favorable bacteriologic, clinical and radiologic evolution. The non-inferiority margin was 12 percentage points.
RESULTS
Of 754 randomized patients, 696 and 559 were included in the modified intention to treat (mITT) and per-protocol (PP) analyses, respectively. In mITT, the control had 80.7% favorable outcomes. Regimens 9BCLLfxZ [adjusted risk difference (aRD): 9.5% (95% confidence interval (CI), 0.4 to 18.6)], 9BLMZ [aRD: 8.8% (95%CI, -0.6 to 18.2)], and 9BDLLfxZ [3.9% (95%CI, -5.8 to 13.6)] were non-inferior in mITT and in PP. The proportion of participants experiencing grade 3 or higher adverse events was similar across the regimens. Grade 3 or higher hepatotoxicity occurred in 11.7% of the experimental regimens overall and in 7.1% of the control.
CONCLUSIONS
The endTB trial increases treatment options for RR-TB with three shortened, all-oral regimens that were non-inferior to a current well-performing standard of care.
ClinicalTrials.gov: NCT02754765
Other > Pre-Print
medRxiv. 2022 February 21; DOI:10.1101/2022.02.17.22271108
Yakum MN, Funwie AD, Ajong AB, Tsafack M, Ebaze LE, et al.
medRxiv. 2022 February 21; DOI:10.1101/2022.02.17.22271108
Immunization is the most cost-effective health intervention in the world yet, vaccination uptake is still low with less than 50% of children aged 12-23 months fully vaccinated Cameroon. The objective of this study was to estimate the burden of vaccine hesitancy associated with routine EPI vaccines in Yaounde-Cameroon. A two-stage cross-sectional cluster survey was conducted in Yaoundé in May-June 2022, targeting parents/guardians of children 0-59 months. Clusters were selected with probability proportionate to size (PPS) and household’s selection done using a restricted sampling method. Data collection was done using an interviewer-administered questionnaire. Data were cleaned using MS-Excel 2019, and analyzed with R version 4.1.0 (2021-05-18). A total of 529 participants were enrolled out of 708 visited, giving a non-response rate of 25%. In total, vaccine hesitancy was reported in 137(25.90[22.35-29.80] %), and vaccine hesitancy prevalence did not vary significantly across different households’ wealth levels (p-value= 0.3786). However, in wealthy households’ refusal of vaccines (14%) was less than in poorer households (20%). Lack of trust, confidence, and perceived complacency are the leading causes of vaccine hesitancy related to routine immunization in Yaounde-Cameroon. We, therefore, recommend that the burden of vaccine hesitancy should be assessed at national scale and identify sources of misinformation that are at the origin of vaccine hesitancy. Having a clear notion of the effect of social media(Facebook, Instagram, WhatsApp, etc,), radio, TV, and other information sources might guide interventions to combat vaccine hesitancy.
Other > Pre-Print
medRxiv. 2021 February 23; DOI:10.1101/2021.02.19.21252071
Fouda Mbarga N, Emilienne E, Mbarga M, Ouamba P, Nanda H, et al.
medRxiv. 2021 February 23; DOI:10.1101/2021.02.19.21252071
OBJECTIVES
This study explores the clinical profiles and factors associated with COVID-19 in Cameroon.
RESEARCH DESIGN AND METHODS
In this prospective cohort study, we followed patients admitted for suspicion of COVID-19 at Djoungolo Hospital between 01st April and 31st July 2020. Patients were categorised by age groups and disease severity: mild (symptomatic without clinical signs of pneumonia pneumonia), moderate (with clinical signs of pneumonia without respiratory distress) and severe cases (clinical signs of pneumonia and respiratory distress not requiring invasive ventilation). Demographic information and clinical features were summarised. Multivariable analysis was performed to predict risk.
RESULTS
A total of 323 patients were admitted during the study period; 262 were confirmed cases of COVID-19 by Polymerase Chain Reaction (PCR). Among the confirmed cases, the male group aged 40 to 49 years (13.9%) was predominant. Disease severity ranged from mild (77%; N=204) to moderate (15%; N=40) to severe (7%; N=18); the case fatality rate was 1% (N=4). Dysgusia (46%; N=111) and hyposmia/anosmia (39%; N=89) were common features of COVID-19. Nearly one-third of patients had comorbidities (29%; N=53), of which hypertension was the most common (20%; N=48). Participation in a mass gathering (OR=5.47; P=0.03) was a risk factor for COVID-19. Age groups 60 to 69 (OR=7.41; P=0.0001), 50 to 59 (OR=4.09; P=0.03), 40 to 49 (OR=4.54; P=0.01), male gender (OR=2.53; P=0.04), diabetes (OR= 4.05; P= 0.01), HIV infection (OR=5.57; P=0.03), lung disease (OR= 6.29; P=0.01), dyspnoea (OR=3.70; P=0.008) and fatigue (OR=3.35; P=0.02) significantly predicted COVID-19 severity.
CONCLUSION
Unlike many high-income settings, most COVID-19 cases in this study were benign with low fatality. Such findings may guide public health decision-making.
This study explores the clinical profiles and factors associated with COVID-19 in Cameroon.
RESEARCH DESIGN AND METHODS
In this prospective cohort study, we followed patients admitted for suspicion of COVID-19 at Djoungolo Hospital between 01st April and 31st July 2020. Patients were categorised by age groups and disease severity: mild (symptomatic without clinical signs of pneumonia pneumonia), moderate (with clinical signs of pneumonia without respiratory distress) and severe cases (clinical signs of pneumonia and respiratory distress not requiring invasive ventilation). Demographic information and clinical features were summarised. Multivariable analysis was performed to predict risk.
RESULTS
A total of 323 patients were admitted during the study period; 262 were confirmed cases of COVID-19 by Polymerase Chain Reaction (PCR). Among the confirmed cases, the male group aged 40 to 49 years (13.9%) was predominant. Disease severity ranged from mild (77%; N=204) to moderate (15%; N=40) to severe (7%; N=18); the case fatality rate was 1% (N=4). Dysgusia (46%; N=111) and hyposmia/anosmia (39%; N=89) were common features of COVID-19. Nearly one-third of patients had comorbidities (29%; N=53), of which hypertension was the most common (20%; N=48). Participation in a mass gathering (OR=5.47; P=0.03) was a risk factor for COVID-19. Age groups 60 to 69 (OR=7.41; P=0.0001), 50 to 59 (OR=4.09; P=0.03), 40 to 49 (OR=4.54; P=0.01), male gender (OR=2.53; P=0.04), diabetes (OR= 4.05; P= 0.01), HIV infection (OR=5.57; P=0.03), lung disease (OR= 6.29; P=0.01), dyspnoea (OR=3.70; P=0.008) and fatigue (OR=3.35; P=0.02) significantly predicted COVID-19 severity.
CONCLUSION
Unlike many high-income settings, most COVID-19 cases in this study were benign with low fatality. Such findings may guide public health decision-making.
Other > Pre-Print
medRxiv. 2023 February 16; DOI:10.1101/2023.02.15.23285976
Klein A, Bastard M, Hemat H, Singh SN, Muniz B, et al.
medRxiv. 2023 February 16; DOI:10.1101/2023.02.15.23285976
BACKGROUND
Though many studies on COVID have been published to date, data on COVID-19 epidemiology, symptoms, risk factors and severity in low- and middle-income countries (LMICS), such as Afghanistan are sparse.
OBJECTIVE
To describe clinical characteristics, severity, and outcomes of patients hospitalized in the MSF COVID-19 treatment center (CTC) in Herat, Afghanistan and to assess risk factors associated with severe outcomes.
METHODS
1113 patients were included in this observational study between June 2020 and April 2022. Descriptive analysis was performed on clinical characteristics, complications, and outcomes of patients. Univariate description by Cox regression to identify risk factors for an adverse outcome was performed. Adverse outcome was defined as death or transfer to a level 3 intensive care located at another health facility. Finally, factors identified were included in a multivariate Cox survival analysis.
RESULTS
A total of 165 patients (14.8%) suffered from a severe disease course, with a median time of 6 days (interquartile range: 2-11 days) from admission to adverse outcome. In our multivariate model, we identified male gender, age over 50, high O2 flow administered during admission, lymphopenia, anemia and O2 saturation <=93% during the first three days of admission as predictors for a severe disease course (p<0.05).
CONCLUSION
Our analysis concluded in a relatively low rate of adverse outcomes of 14.8%. This is possibly related to the fact, that the resources at an MSF-led facility are higher, in terms of human resources as well as supply of drugs and biomedical equipment, including oxygen therapy devices, compared to local hospitals. Predictors for severe disease outcomes were found to be comparable to other settings.
Though many studies on COVID have been published to date, data on COVID-19 epidemiology, symptoms, risk factors and severity in low- and middle-income countries (LMICS), such as Afghanistan are sparse.
OBJECTIVE
To describe clinical characteristics, severity, and outcomes of patients hospitalized in the MSF COVID-19 treatment center (CTC) in Herat, Afghanistan and to assess risk factors associated with severe outcomes.
METHODS
1113 patients were included in this observational study between June 2020 and April 2022. Descriptive analysis was performed on clinical characteristics, complications, and outcomes of patients. Univariate description by Cox regression to identify risk factors for an adverse outcome was performed. Adverse outcome was defined as death or transfer to a level 3 intensive care located at another health facility. Finally, factors identified were included in a multivariate Cox survival analysis.
RESULTS
A total of 165 patients (14.8%) suffered from a severe disease course, with a median time of 6 days (interquartile range: 2-11 days) from admission to adverse outcome. In our multivariate model, we identified male gender, age over 50, high O2 flow administered during admission, lymphopenia, anemia and O2 saturation <=93% during the first three days of admission as predictors for a severe disease course (p<0.05).
CONCLUSION
Our analysis concluded in a relatively low rate of adverse outcomes of 14.8%. This is possibly related to the fact, that the resources at an MSF-led facility are higher, in terms of human resources as well as supply of drugs and biomedical equipment, including oxygen therapy devices, compared to local hospitals. Predictors for severe disease outcomes were found to be comparable to other settings.
Other > Pre-Print
medRxiv. 2024 February 18; DOI:10.1101/2024.02.16.24302942
de Vrij N, Vandoren R, Ramadan K, Van Hul A, Kassa M, et al.
medRxiv. 2024 February 18; DOI:10.1101/2024.02.16.24302942
Human immunodeficiency virus (HIV) co-infection is a major challenge for visceral leishmaniasis (VL) control, particularly in Ethiopia where the incidence of both pathogens is high. VL-HIV often leads to high rates of antileishmanial treatment failure and recurrent VL disease relapses. Considering the high prevalence of HIV and Leishmania in the Ethiopian population, preventing the progression of asymptomatic Leishmania infection to disease would be a valuable asset to VL disease control and to the clinical management of people living with HIV (PLWH). However, such a strategy requires good understanding of risk factors for VL development. In immunocompetent individuals living in Brazil, India, or Iran, the Human Leukocyte Antigen (HLA) gene region has been associated with VL development. We used NanoTYPE, an Oxford Nanopore Technologies sequencing-based HLA genotyping method, to detect associations between HLA genotype and VL development by comparing 78 PLWH with VL history and 46 PLWH that controlled a Leishmania infection, all living in a VL endemic region of North-West Ethiopia. We identified a strong association between HLA-A*03:01 and increased risk of VL development (OR = 3.89). These data provide candidate HLA alleles that can be further explored for inclusion in a potential Leishmania screen-and-treat strategy in VL endemic regions.
Journal Article > ResearchFull Text
medRxiv. 2021 January 26; DOI:10.1101/2021.01.25.21250446
Roederer T, Llosa AE, Shepherd S, Defourny I, Lacharite M, et al.
medRxiv. 2021 January 26; DOI:10.1101/2021.01.25.21250446
Background We present results from an intervention case study, the Soins Preventifs de l’Enfant (SPE) project, in Konséguéla health area, Mali. The intervention involved a network of community health workers providing a comprehensive preventive/therapeutic package, ultimately aiming at reducing under 24-month mortality. Associated costs were documented to assess the feasibility of replication and scale-up.
Methods SPE program monitoring data were obtained from booklets specific to the program between 2010 and 2014. Data included sex, age, vaccination status, anthropometric measurements, Ready-To-Use-Supplementary Food distribution, morbidities reported by the mother between visits, hospitalizations over 18 months of follow-up. Cross-sectional surveys in the district of Koutiala, of which Konséguéla is one health area, were conducted yearly between 2010 and 2014 for comparison, using difference-in-difference approach. Ethical approval was granted from the Malian Ethical Committee.
Results Global and Severe Acute Malnutrition prevalences decreased over time in Konséguéla as well as in the rest of the district, but the difference between areas was not significant. Children reaching 24 months were 20% less stunted in Konséguéla than children the same age outside (p<0.001). Mortality rates significantly decreased more in Konséguéla, while vaccination coverage for all antigens significantly increased in the meantime. The package cost approximately USD 95 per child per year; 56% of which was for the RUSF.
Conclusion The results of this case study suggest a sustained impact of a community based, comprehensive health package on major child health indicators. Most notably, while improvements in acute malnutrition were found in the district as a whole, those in the intervention area were more pronounced. Trends for other indicators suggest additional benefits.
Methods SPE program monitoring data were obtained from booklets specific to the program between 2010 and 2014. Data included sex, age, vaccination status, anthropometric measurements, Ready-To-Use-Supplementary Food distribution, morbidities reported by the mother between visits, hospitalizations over 18 months of follow-up. Cross-sectional surveys in the district of Koutiala, of which Konséguéla is one health area, were conducted yearly between 2010 and 2014 for comparison, using difference-in-difference approach. Ethical approval was granted from the Malian Ethical Committee.
Results Global and Severe Acute Malnutrition prevalences decreased over time in Konséguéla as well as in the rest of the district, but the difference between areas was not significant. Children reaching 24 months were 20% less stunted in Konséguéla than children the same age outside (p<0.001). Mortality rates significantly decreased more in Konséguéla, while vaccination coverage for all antigens significantly increased in the meantime. The package cost approximately USD 95 per child per year; 56% of which was for the RUSF.
Conclusion The results of this case study suggest a sustained impact of a community based, comprehensive health package on major child health indicators. Most notably, while improvements in acute malnutrition were found in the district as a whole, those in the intervention area were more pronounced. Trends for other indicators suggest additional benefits.
Other > Pre-Print
medRxiv. 2022 March 31; DOI:10.1101/2022.03.28.22273032
Lightowler M, Manangazira P, Nackers F, Van Herp M, Phiri I, et al.
medRxiv. 2022 March 31; DOI:10.1101/2022.03.28.22273032
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.