A Multicentre Study of Shigella Diarrhoea in Six Asian Countries: Disease Burden, Clinical Manifestations, and Microbiology

Abstract

BackgroundThe 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.Methods and FindingsOver 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%]).ConclusionsShigella 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.

Genetic characteristics and changing antimicrobial resistance among Shigella spp. isolated from hospitalized diarrhoeal patients in Kolkata, India

“…From that time, fluoroquinolone resistance has increased in developing countries, and also among other serogroups of Shigella. After S. dysenteriae type 1 acquired fluoroquinolone resistance, its incidence began declining and finally (Kuo et al, 2008;von Seidlein et al, 2006). The incidence of fluoroquinolone resistance is rising year by year in other serogroups of Shigella spp.…”

Changing species distribution and antimicrobial susceptibility pattern ofShigellaover a 29-year period (1980–2008)

“…9/1000 person-years, but the rate was 60 % higher (13 . 2/1000 person years) in children aged <5 years [2]. Childhood malnutrition is a major public health problem in Bangladesh, where >40 % of pre-schoolchildren are malnourished [3] ; these children are not only at higher risk of Shigella infections, but also experience complications and fatal outcomes more often [4,5].…”

Tracking the establishment of local endemic populations of an emergent enteric pathogen

“…enteric disease | drug resistance | phylogeography | genomics T he bacterium Shigella sonnei is a human-adapted bacterial pathogen that accounts for approximately one-sixth of the global dysentery burden of >160 million infections and 1 million deaths annually (1,2). We have recently shown that S. sonnei emerged in Europe ∼500 y ago and spread intercontinentally in the last few decades to establish new and locally evolving populations in countries where it is now considered endemic (3).…”