Epidemiology, clinical presentation, and patterns of drug resistance of Salmonella Typhi in Karachi, Pakistan

  • M. Imran Khan Aga Khan University, Karachi, Pakistan
  • Sajid Bashir Soofi Aga Khan University, Karachi, Pakistan
  • R. Leon Ochiai International Vaccine Institute, Seoul, South Korea
  • Mohammad Jawed Khan Aga Khan University, Karachi, Pakistan
  • Shah Muhammad Sahito Aga Khan University, Karachi, Pakistan
  • Mohammad Atif Habib Aga Khan University, Karachi, Pakistan
  • Mahesh K Puri International Vaccine Institute, Seoul, South Korea
  • Lorenz von Seidlein International Vaccine Institute, Seoul, South Korea
  • Jin Kyung Park International Vaccine Institute, Seoul, South Korea
  • Young Ae You International Vaccine Institute, Seoul, South Korea
  • Mohammad Ali International Vaccine Institute, Seoul, South Korea
  • S. Qamarudding Nizami Aga Khan University, Karachi, Pakistan
  • Camilo J Acosta International Vaccine Institute, Seoul, South Korea
  • Richard Bradley Sack Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
  • John D Clemens International Vaccine Institute, Seoul, South Korea
  • Zulfiqar A Bhutta Aga Khan University, Karachi, Pakistan

Abstract

Introduction: Enteric fever remains a major public health problem in Asia. Planning appropriate preventive measures such as immunization requires a clear understanding of disease burden. We conducted a community-based surveillance for Salmonella Typhi infection in children in Karachi, Pakistan.

Methodology: A de jure household census was conducted at baseline in the study setting to enumerate all individuals. A health-care facility-based passive surveillance system was used to capture episodes of fever lasting three or more 3 days in children 2 to 16 years old.

Results: A total of 7,401 blood samples were collected for microbiological confirmation, out of which 189 S. Typhi and 32 S. Paratyphi A isolates were identified with estimated annual incidences of 451/100,000 (95% CI: 446 – 457) and 76/100,000 (95% CI: 74 – 78) respectively. At the time of presentation, after adjusting for age, there was an association between the duration of fever and temperature at presentation, and being infected with multidrug-resistant S. Typhi. Of 189 isolates 83 were found to be resistant to first-line antimicrobial therapy. There was no statistically significant difference in clinical presentation of blood culture sensitive and resistant S. Typhi isolates.

Conclusion: Incidence of S. Typhi in children is high in urban squatter settlements of Karachi, Pakistan. Findings from this study identified duration of fever and temperature at the time of presentation as important symptoms associated with blood culture-confirmed typhoid fever. Preventive strategies such as immunization and improvements in water and sanitation conditions should be the focus of typhoid control in urban settlements of Pakistan.

Author Biography

M. Imran Khan, Aga Khan University, Karachi, Pakistan

Research Scientist

Translational Research Division

Published
2012-10-19
How to Cite
Khan M, Soofi S, Ochiai R, Khan M, Sahito S, Habib M, Puri M, von Seidlein L, Park J, You Y, Ali M, Nizami S, Acosta C, Sack R, Clemens J, Bhutta Z (2012) Epidemiology, clinical presentation, and patterns of drug resistance of Salmonella Typhi in Karachi, Pakistan. The Journal Of Infection In Developing Countries 6 (10): 704-714. https://doi.org/10.3855/jidc.1967
Section
Original Articles

Keywords

S. Typhi; population-based incidence; drug resistance; Pakistan