Table 1.

Studies investigating the contributions of non-typhoidal Salmonella (NTS) to human diarrhoeal disease in Vietnam.

Citation	Study date	Study location	Sample size	Age	Study type	NTS prevalence	Other aetiologies and observations
Ngan et al. (1992)	1988–1989	Hanoi	83 diarrhoea cases	<3 years	Hospital-based study	No cases detected	24% had ETEC isolated, 8% had EPEC, 5% rotavirus, 6% Candida, and 4% Giardia lamblia
Isenbarger et al. (2001)	1998–1999	Red River Delta (3 communes)	1,655 healthy children in longitudinal study; 2,160 diarrhoea cases; 203 controls	<5 years	Longitudinal (community), hospital-based case-control study	0.8% cases, 1% controls	Diarrhoea incidence: 1.3 episodes/child/year. Only bacterial aetiologies investigated: Main aetiologies (cases vs. controls): Campylobacter spp. (6.8 vs. 3.8%), Shigella spp. (6.5 vs. 1.5%), ETEC (6.5 vs 4.4%)
Bodhidatta et al. (2007)	2001	Hanoi	291 diarrhoea cases; 291 controls	<5 years	Hospital-based case-control study	7% cases; 1% controls	Main aetiologies (cases vs. controls): Rotavirus (31% vs. 3%); Aeromonas (15% vs. 8%); Astrovirus (12% vs. 1%); Shigella (9% and 1%); Campylobacter (4% and 0%); Adenovirus (4% vs. 1%) and ETEC (3.0% vs. 0%)
Nguyen et al. (2004); Vu Nguyen et al. (2006)	2001–2002	Hanoi	587 diarrhoea cases; 249 controls	<5 years	Hospital-based case-control study	No cases detected	Main aetiologies (cases vs. controls): Rotavirus (46.7 vs. 3.6%), EAEC (11.6% vs. 7.2%), EPEC (6.6 vs. 4.4%), ETEC (2.2 vs. 0.4%); Shigella spp. (4.8 vs. 0%). Campylobacter isolation not attempted.
Khan et al. (2010)	2001–2003	International study including hospital in Hue (central Vietnam)	3611 febrile patients	5 to 15 years	Hospital-based	No cases detected	S. typhi detected in 18 cases (0.5%) in Hue; International study. Other sites in Pakistan, India, and Indonesia also included
Hien et al. (2007)	2002–2004	Hanoi; suburban area using wastewater for agriculture and aquaculture	222 children enrolled in longitudinal study; 111 diarrhoea cases; 111 controls	<6 years	Longitudinal (community), hospital-based case-control study	3.6% cases; 2.7% controls	Diarrhoea incidence: 0.63 episodes/child/year. Aetiologies (cases vs. controls): Rotavirus (17.1% vs. 4.5%), Entamoeba hystolitica (15.3% vs. 4.5%), diarrhoeagenic E. coli (22.5 vs. 23.4%), Shigella spp. (6.0 vs. 0%), Campylobacter spp. (1.8 vs. 1.8%)
Do et al. (2007)	2002–2004	Red River Delta	636 healthy adults in longitudinal study; 163 cases and 163 controls	15–70 years	Longitudinal (community), hospital-based case–control study	0.6% cases; 3.1% controls	Diarrhoea incidence: 0.28 episodes per adult per year. Aetiologies (cases vs. controls): E. hystolitica (9.9 vs. 0%); Diarrhoeagenic E. coli (13.5 vs. 9.8%); Shigella (3.1 vs. 1.2%); C. jejuni (0.6 vs. 0%); rotavirus (3.7 vs. 0.6%)
Thompson et al. (2012)	2009–2010	HCMC	1,419 diarrhoea cases	<5 years	Hospital-based study	5.4% cases (of which 58% were Group B)	Main independent risk factors: diarrhoeal contact (OR = 6.0) and living in a household with >2 children (OR = 2.3)