1 International Vaccine Institute, Seoul, Korea, 2 Fudan University, Shanghai, China, 3 National Institute of Hygiene and Epidemiology, Hanoi, Vietnam, 4 Facu1lty of Allied Health Sciences, Thammasat University, Rangsit Center, Patumthani, Thailand, 5 National Institute of Health Research and Development, Jakarta Indonesia, Ministry of Health, Jakarta, Indonesia, 6 Centre for Health and Population Research, Dhaka, Bangladesh, 7 Department of Paediatrics, The Aga Khan University, Karachi, Pakistan, 8 United States Armed Forces Research Institute for Medical Sciences, Bangkok, Thailand, 9 Centers for Vaccine Development, Baltimore, Maryland, United States of America
The burden of shigellosis is greatest in resource-poor countries. Although this diarrheal disease has been thought to cause considerable morbidity and mortality in excess of 1,000,000 deaths globally per year, little recent data are available to guide intervention strategies in Asia. We conducted a prospective, population-based study in six Asian countries to gain a better understanding of the current disease burden, clinical manifestations, and microbiology of shigellosis in Asia.
Over 600,000 persons of all ages residing in Bangladesh, China, Pakistan, Indonesia, Vietnam, and Thailand were included in the surveillance. Shigella was isolated from 2,927 (5%) of 56,958 diarrhoea episodes detected between 2000 and 2004. The overall incidence of treated shigellosis was 2.1 episodes per 1,000 residents per year in all ages and 13.2/1,000/y in children under 60 months old. Shigellosis incidence increased after age 40 years. S. flexneri was the most frequently isolated Shigella species (1,976/2,927 [68%]) in all sites except in Thailand, where S. sonnei was most frequently detected (124/146 [85%]). S. flexneri serotypes were highly heterogeneous in their distribution from site to site, and even from year to year. PCR detected ipaH, the gene encoding invasion plasmid antigen H in 33% of a sample of culture-negative stool specimens. The majority of S. flexneri isolates in each site were resistant to amoxicillin and cotrimoxazole. Ciprofloxacin-resistant S. flexneri isolates were identified in China (18/305 [6%]), Pakistan (8/242 [3%]), and Vietnam (5/282 [2%]).
Shigella appears to be more ubiquitous in Asian impoverished populations than previously thought, and antibiotic-resistant strains of different species and serotypes have emerged. Focusing on prevention of shigellosis could exert an immediate benefit first by substantially reducing the overall diarrhoea burden in the region and second by preventing the spread of panresistant Shigella strains. The heterogeneous distribution of Shigella species and serotypes suggest that multivalent or cross-protective Shigella vaccines will be needed to prevent shigellosis in Asia.
Funding: This work was supported by the Diseases of the Most Impoverished Program, funded by the Bill and Melinda Gates Foundation and the Swedish International Development Cooperation Agency. The funding institution was informed at regular intervals about the progress of the project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Academic Editor: Philippe J. Sansonetti, Institut Pasteur, France
Received: February 13, 2006; Accepted: June 21, 2006; Published: September 12, 2006
DOI: 10.1371/journal.pmed.0030353
Copyright: © 2006 von Seidlein et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abbreviation: CI, confidence interval
* To whom correspondence should be addressed. E-mail: lseidlein@ivi.int
Citation: von Seidlein L, Kim DR, Ali M, Lee H, Wang X, et al. (2006) A Multicentre Study of Shigella Diarrhoea in Six Asian Countries: Disease Burden, Clinical Manifestations, and Microbiology. PLoS Med 3(9): e353
