Impact of a Typhoid Conjugate Vaccine Campaign on Antimicrobial Use in Harare, Zimbabwe (360G-Wellcome-219736_A_19_Z)

Typhoid fever is a common cause of non-specific febrile illness in low-resource settings. Empirical treatment for typhoid may be a major driver of AMR in typhoid-endemic communities, where estimates suggest that up to 25 additional cases receive antimicrobial treatment for each one confirmed. Harare in Zimbabwe has experienced a major increase in typhoid since 2016, with recent emergence of ciprofloxacin-resistance. In February 2019 a mass typhoid vaccine campaign was performed, targeting infants and children living in 9 affected suburbs with the new typhoid conjugate vaccine (TCV). In work being performed at primary health clinics in these densely-populated suburbs as part of the FIEBRE study, which aims to assess the causes of febrile illness in low-resource settings, we have already identified a significant reduction in typhoid in vaccinated children. In this project our key goals are to investigate the impact of the 2019 mass TCV campaign on antimicrobial resistance in S. Typhi and on antimicrobial prescribing and related practices in community clinics. Defining these effects will have major policy implications for TCV use, both locally, in determining the benefits of further routine/repeat vaccination, and internationally to inform estimates of the direct and indirect impacts on AMR infection and antimicrobial use.