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.
Journal Article > ResearchFull Text
Vaccine. 2022 August 2; Volume 12; 100201.; DOI:10.1016/j.jvacx.2022.100201
Poncin M, Marembo J, Chitando P, Sreenivasan N, Makwara I, et al.
Vaccine. 2022 August 2; Volume 12; 100201.; DOI:10.1016/j.jvacx.2022.100201
INTRODUCTION
Typhoid fever is a public-health problem in Harare, the capital city of Zimbabwe, with seasonal outbreaks occurring annually since 2010. In 2019, the Ministry of Health and Child Care (MOHCC) organized the first typhoid conjugate vaccination campaign in Africa in response to a recurring typhoid outbreak in a large urban setting.
METHODS
As part of a larger public health response to a typhoid fever outbreak in Harare, Gavi approved in September 2018 a MOHCC request for 340,000 doses of recently prequalified Typbar-TCV to implement a mass vaccination campaign. To select areas for the campaign, typhoid fever surveillance data from January 2016 until June 2018 was reviewed. We collected and analyzed information from the MOHCC and its partners to describe the vaccination campaign planning, implementation, feasibility, administrative coverage and financial costs.
RESULTS
The campaign was conducted in nine high-density suburbs of Harare over eight days in February-March 2019 and targeted all children aged 6 months-15 years; however, the target age range was extended up to 45 years in one suburb due to the past high attack rate among adults. A total of 318,698 people were vaccinated, resulting in overall administrative coverage of 85.4 percent. More than 750 community volunteers and personnel from the MOHCC and the Ministry of Education were trained and involved in social mobilization and vaccination activities. The MOHCC used a combination of vaccination strategies (i.e., fixed and mobile immunization sites, a creche and school-based strategy, and door-to-door activities). Financial costs were estimated at US$ 2.39 per dose, including the vaccine and vaccination supplies (US$ 0.79 operational costs per dose excluding vaccine and vaccination supplies).
CONCLUSIONS
A mass targeted campaign in densely populated urban areas in Harare, using the recently prequalified typhoid conjugate vaccine, was feasible and achieved a high overall coverage in a short period of time.
Typhoid fever is a public-health problem in Harare, the capital city of Zimbabwe, with seasonal outbreaks occurring annually since 2010. In 2019, the Ministry of Health and Child Care (MOHCC) organized the first typhoid conjugate vaccination campaign in Africa in response to a recurring typhoid outbreak in a large urban setting.
METHODS
As part of a larger public health response to a typhoid fever outbreak in Harare, Gavi approved in September 2018 a MOHCC request for 340,000 doses of recently prequalified Typbar-TCV to implement a mass vaccination campaign. To select areas for the campaign, typhoid fever surveillance data from January 2016 until June 2018 was reviewed. We collected and analyzed information from the MOHCC and its partners to describe the vaccination campaign planning, implementation, feasibility, administrative coverage and financial costs.
RESULTS
The campaign was conducted in nine high-density suburbs of Harare over eight days in February-March 2019 and targeted all children aged 6 months-15 years; however, the target age range was extended up to 45 years in one suburb due to the past high attack rate among adults. A total of 318,698 people were vaccinated, resulting in overall administrative coverage of 85.4 percent. More than 750 community volunteers and personnel from the MOHCC and the Ministry of Education were trained and involved in social mobilization and vaccination activities. The MOHCC used a combination of vaccination strategies (i.e., fixed and mobile immunization sites, a creche and school-based strategy, and door-to-door activities). Financial costs were estimated at US$ 2.39 per dose, including the vaccine and vaccination supplies (US$ 0.79 operational costs per dose excluding vaccine and vaccination supplies).
CONCLUSIONS
A mass targeted campaign in densely populated urban areas in Harare, using the recently prequalified typhoid conjugate vaccine, was feasible and achieved a high overall coverage in a short period of time.
Conference Material > Abstract
Lightowler M
Epicentre Scientific Day Paris 2021. 2021 June 10
BACKGROUND
Zimbabwe has suffered regular outbreaks of typhoid fever, with most of the reported cases concentrated in Harare, the capital city of the country. Typhoid fever might have become endemic in Harare with many cases reported annually since 2010. Many suburbs of Harare notify cases and since October 2017, the incidence has substantially increased.
OBJECTIVES
The main objective was to estimate the vaccination effectiveness of the typhoid conjugate vaccine (TCV) used as a part of the large mass vaccination campaign in response to the Typhoid fever regular outbreaks in Harare and conducted in March 2019.
METHODS
A case-control study, using 2 sets of controls (facility matched controls and community matched controls) in 3 urban suburbs of Harare known for being prone to typhoid fever outbreaks and targeted by the TCV vaccination campaign.
PARTICIPANTS
Of the 502 suspected cases enrolled in 4 health facility sites in Harare from July 2019 to March 2020, 148 laboratory-confirmed typhoid fever cases and 153 controls confirmed negative were identified. 105 (47 between 6 months to 15 years old) confirmed cases were age sex and residence place 1:1 matched with 105 facility-based controls matched. 96 confirmed cases were 1:5 age sex and immediate neighbour matched with 229 community controls.
RESULTS
In the primary analysis, the adjusted VE estimation for one dose of TCV was 75.2% (95% CI, 0.6 to 93.8) when confirmed typhoid fever cases were matched with facility controls and 81.0% (95% CI, 46.5 to 92.9) when matched with community controls.
CONCLUSIONS
This study confirms that one vaccine dose of TCV can be an effective tool to control Typhoid fever in the population between 6 month and 15 years old and provides information on an African setting after the first mass vaccination campaign in the continent providing information under real life conditions.
This abstract is not to be quoted for publication.
Zimbabwe has suffered regular outbreaks of typhoid fever, with most of the reported cases concentrated in Harare, the capital city of the country. Typhoid fever might have become endemic in Harare with many cases reported annually since 2010. Many suburbs of Harare notify cases and since October 2017, the incidence has substantially increased.
OBJECTIVES
The main objective was to estimate the vaccination effectiveness of the typhoid conjugate vaccine (TCV) used as a part of the large mass vaccination campaign in response to the Typhoid fever regular outbreaks in Harare and conducted in March 2019.
METHODS
A case-control study, using 2 sets of controls (facility matched controls and community matched controls) in 3 urban suburbs of Harare known for being prone to typhoid fever outbreaks and targeted by the TCV vaccination campaign.
PARTICIPANTS
Of the 502 suspected cases enrolled in 4 health facility sites in Harare from July 2019 to March 2020, 148 laboratory-confirmed typhoid fever cases and 153 controls confirmed negative were identified. 105 (47 between 6 months to 15 years old) confirmed cases were age sex and residence place 1:1 matched with 105 facility-based controls matched. 96 confirmed cases were 1:5 age sex and immediate neighbour matched with 229 community controls.
RESULTS
In the primary analysis, the adjusted VE estimation for one dose of TCV was 75.2% (95% CI, 0.6 to 93.8) when confirmed typhoid fever cases were matched with facility controls and 81.0% (95% CI, 46.5 to 92.9) when matched with community controls.
CONCLUSIONS
This study confirms that one vaccine dose of TCV can be an effective tool to control Typhoid fever in the population between 6 month and 15 years old and provides information on an African setting after the first mass vaccination campaign in the continent providing information under real life conditions.
This abstract is not to be quoted for publication.
Journal Article > ReviewAbstract Only
J Antimicrob Chemother. 2020 December 21; Volume 76 (Issue 5); 1160-1167.; DOI:10.1093/jac/dkaa519
Mashe T, Leekitcharoenphon P, Mtapuri-Zinyowera S, Kingsley RA, Robertson V, et al.
J Antimicrob Chemother. 2020 December 21; Volume 76 (Issue 5); 1160-1167.; DOI:10.1093/jac/dkaa519
BACKGROUND
Typhoid fever, caused by S. enterica ser. Typhi, continues to be a substantial health burden in developing countries. Little is known of the genotypic diversity of S. enterica ser. Typhi in Zimbabwe, but this is key for understanding the emergence and spread of this pathogen and devising interventions for its control.
OBJECTIVES
To report the molecular epidemiology of S. enterica ser. Typhi outbreak strains circulating from 2012 to 2019 in Zimbabwe, using comparative genomics.
METHODS
A review of typhoid cases records from 2012 to 2019 in Zimbabwe was performed. The phylogenetic relationship of outbreak isolates from 2012 to 2019 and emergence of antibiotic resistance was investigated by whole-genome sequence analysis.
RESULTS
A total 22 479 suspected typhoid cases, 760 confirmed cases were reported from 2012 to 2019 and 29 isolates were sequenced. The majority of the sequenced isolates were predicted to confer resistance to aminoglycosides, β-lactams, phenicols, sulphonamides, tetracycline and fluoroquinolones (including qnrS detection). The qnrS1 gene was associated with an IncN (subtype PST3) plasmid in 79% of the isolates. Whole-genome SNP analysis, SNP-based haplotyping and resistance determinant analysis showed that 93% of the isolates belonged to a single clade represented by multidrug-resistant H58 lineage I (4.3.1.1), with a maximum pair-wise distance of 22 SNPs.
CONCLUSIONS
This study has provided detailed genotypic characterization of the outbreak strain, identified as S. Typhi 4.3.1.1 (H58). The strain has reduced susceptibility to ciprofloxacin due to qnrS carried by an IncN (subtype PST3) plasmid resulting from ongoing evolution to full resistance.
Typhoid fever, caused by S. enterica ser. Typhi, continues to be a substantial health burden in developing countries. Little is known of the genotypic diversity of S. enterica ser. Typhi in Zimbabwe, but this is key for understanding the emergence and spread of this pathogen and devising interventions for its control.
OBJECTIVES
To report the molecular epidemiology of S. enterica ser. Typhi outbreak strains circulating from 2012 to 2019 in Zimbabwe, using comparative genomics.
METHODS
A review of typhoid cases records from 2012 to 2019 in Zimbabwe was performed. The phylogenetic relationship of outbreak isolates from 2012 to 2019 and emergence of antibiotic resistance was investigated by whole-genome sequence analysis.
RESULTS
A total 22 479 suspected typhoid cases, 760 confirmed cases were reported from 2012 to 2019 and 29 isolates were sequenced. The majority of the sequenced isolates were predicted to confer resistance to aminoglycosides, β-lactams, phenicols, sulphonamides, tetracycline and fluoroquinolones (including qnrS detection). The qnrS1 gene was associated with an IncN (subtype PST3) plasmid in 79% of the isolates. Whole-genome SNP analysis, SNP-based haplotyping and resistance determinant analysis showed that 93% of the isolates belonged to a single clade represented by multidrug-resistant H58 lineage I (4.3.1.1), with a maximum pair-wise distance of 22 SNPs.
CONCLUSIONS
This study has provided detailed genotypic characterization of the outbreak strain, identified as S. Typhi 4.3.1.1 (H58). The strain has reduced susceptibility to ciprofloxacin due to qnrS carried by an IncN (subtype PST3) plasmid resulting from ongoing evolution to full resistance.
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.
Conference Material > Video (talk)
Lightowler M
Epicentre Scientific Day Paris 2021. 2021 June 10