Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Findings reveal resistance patterns for a priority pathogen--also known as typhoid fever--with high mortality and morbidity in resource-constrained settings

World map showing the prevalence of Fluoroquinolone non-susceptible Salmonella Typhi, 2019
Fluoroquinolone non-susceptible Salmonella Typhi, 2019

Enteric fever, a serious bloodstream infection caused by Salmonella Typhi and Salmonella Paratyphi A, is contracted by consuming water or food that has been contaminated by the bacteria. Enteric fever continues to pose a significant health threat, particularly in low-income and middle-income countries. A groundbreaking study in Lancet Global Health, 'Estimating the subnational prevalence of antimicrobial resistant Salmonella enterica serovars Typhi and Paratyphi A infections in 75 endemic countries, 1990–2019: a modelling study', sheds light on the escalating prevalence of antimicrobial resistance (AMR) in these pathogens.

The study, conducted by the GRAM Typhoid Collaborators, an international team of researchers, utilised a Bayesian spatiotemporal modelling framework to estimate the percentage of multidrug resistance (MDR), fluoroquinolone non-susceptibility (FQNS), and third-generation cephalosporin resistance in Salmonella Typhi and Paratyphi A infections in 75 endemic countries from 1990 to 2019.

Key findings from the study include:

  • A decline in MDR Salmonella Typhi in South Asia and Southeast Asia, contrasted with a concerning increase in sub-Saharan Africa, where the overall prevalence rose from 6·0% in 1990 to 72·7% in 2019.
  • Rapid escalation of FQNS Salmonella Typhi in South Asia, reaching 95·2% in 2019, translating to 7·4 million infections in endemic countries.
  • Low prevalence of third-generation cephalosporin-resistant Salmonella Typhi across most endemic areas, except for Pakistan, where resistance reached 61·0% in 2019.
  • While MDR and cephalosporin resistance in Salmonella Paratyphi A remain low, a significant increase in FQNS took place, reaching 95·0% in 2019.

Dr Annie Browne, a spatial modeller and the first author of the study, emphasizes the urgency of addressing AMR in enteric fever, stating, 'The rise of antimicrobial resistance in S. Typhi and S. Paratyphi A is a pressing public health issue, jeopardizing our ability to treat enteric fever effectively. Our research can guide urgently needed public health interventions to curb this life-threatening disease'.

Prof Sadia Shakoor from the Aga Khan University in Karachi, Pakistan, who also took part in the research, added: 'The impact of AMR is disproportionately felt in regions where resources are limited, exacerbating inequalities. Implementing effective WASH (Water, Sanitation, and Hygiene) initiatives and vaccinations can significantly reduce the burden of enteric fever and other waterborne diseases, paving the way for healthier communities'.

Prof Christiane Dolecek, from the Centre for Tropical Medicine and Global Health at the University of Oxford, and the study's corresponding author, highlighted the significance of the findings for global health policy: 'This extensive analysis provides critical insights into the dynamics of AMR in enteric fever over 30 years. Our research underscores the urgent need for comprehensive public health strategies to combat AMR and reduce the number of enteric fever infections through access to clean water, improved sanitation, and the integration of typhoid fever vaccines into national immunisation programmes'.

The study, supported by the Fleming Fund of the UK Department of Health and Social Care, the Wellcome Trust, and the Bill and Melinda Gates Foundation, underscores the importance of concerted global efforts to combat antimicrobial resistance and enhance public health interventions in endemic regions.

The GRAM (Global Research on Antimicrobial Resistance) Project is a partnership between the University of Oxford and the Institute for Health Metrics and Evaluations at the University of Washington, to estimate the global burden of AMR.

Full results from this manuscript can also be viewed from an interactive data visualization tool.

The full News is available on the GRAM website.

Similar stories