Our data additionally suggests that international travel may have resulted in the dissemination of Central Asia clade S. sonnei beyond Bhutan and the remainder of the Indian subcontinent. S. sonnei isolates with similar PFGE patterns to the strains in this analysis have been recovered from cases of travel-associated shigellosis in Ireland (De Lappe et al., 2015) and in a Shigella outbreak amongst ‘men who have sex with men’ in Canada (Gaudreau et al., 2011). The S. sonnei isolated from both instances were found to be ciprofloxacin-resistant. Studies conducted in Japan have established a strong association between this pulsotype and travel to India, and increasing prevalence of nalidixic acid-resistant S. sonnei has been observed since 2001 (Uchimura et al., 2001; Izumiya et al., 2009). Shigellosis surveys in Iran conducted from 2008 to 2012 have repeatedly shown that this characteristic Asian pulsotype is prevalent and endemic, and that these strains also possess a similar class 2 integron (dfrA1, sat1), but exhibit variability in their ciprofloxacin susceptibility phenotype (Tajbakhsh et al., 2012; Eftekhari et al., 2013; Alizadeh-Hesar et al., 2015). The first case of fluoroquinolone-resistant S. sonnei was identified in Japan in 1993 (Horiuchi et al., 1993). Since then, the incidence of ciprofloxacin-resistant Shigella in Asia and Africa has risen dramatically, from 3.9 % in 2001–2003 to 29.1 % in 2007–2009 (Gu et al., 2012). The potential emergence and dissemination of fluoroquinolone-resistant S. sonnei poses a substantial threat to public health, including low shigellosis burden areas in developed nations, as again substantiated by the recent fluoroquinolone-resistant S. sonnei outbreak in the USA (Bowen et al., 2015). Taken together, these data strongly suggest that the Central Asia clade of S. sonnei is widely present across South Asia and beyond, and may represent an emerging threat to public health.