Page 53 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

Evidence overview

The first three studies 53,57,58 gave information on the proportion of children with enteric pathogens
isolated but all these studies were hospital based and conducted before 1990. Of the remaining
studies, four 59–62 gave information on viral pathogens isolated in children with gastroenteritis but
they all provided regional data. The last published paper is a population-based study comparing
11
the incidence of gastroenteritis in the community with that in patients presenting to their general
practitioner, but in this paper the study population included both adults and children. Since no
published data were available for the overall incidence of enteric pathogens in children with
gastroenteritis from England and Wales, this information was collected from the website of the
UK HPA (www.hpa.org.uk).
53
A prospective study included 1148 children younger than 16 years admitted to a sub-regional
infectious disease hospital with a diagnosis of gastroenteritis over a 1 year period (1986–87).
The demographic characteristics of the study population have been described in detail in
Section 3.1 above. In this study, 8.8% of children (101/1148) were clinically dehydrated, with
1% assessed to have greater than 5% dehydration. Dehydrated children were more likely to have
an enteric pathogen identified compared with those without clinical dehydration (61% versus
43%; P < 0.001). Stool examination identified enteric pathogens in altogether 44.6% of cases
(512/1148), with rotavirus being the most common (in 31%). The common bacterial pathogens
isolated were salmonella spp. (5%), campylobacter spp. (3.2%), and enteropathogenic E. coli
(2%), while cryptosporidium (1.4%) was the most common protozoal organism detected. [EL = 3]

57
The second study was a prospective survey that recruited 447 children younger than 2 years and
admitted to a hospital with gastroenteritis over a 1 year period (1981–82). Seventy-four percent
of the children were younger than 1 year and two-thirds of under-1-year-olds were younger than
6 months. Pathogenic enteric organisms were isolated in 75% of cases (335/447), with viruses
alone in 57%, bacteria alone in 6% and both viruses and bacteria isolated in 10% of cases.
Rotavirus was the most common organism isolated, in 34% of cases (152/447), while all other
viruses were detected in 53% of children. Enteropathogenic E. coli (6.9%), Campylobacter jejuni
(5.1%), Clostridium difficile toxin (4.9%), salmonella spp. (4.3%) and shigella spp. (2%) were the
main bacteria isolated. [EL = 3]
58
The third study included 215 children admitted to four paediatric units in south Wales with
gastroenteritis over a 1 year period (1987–88). The age of the study population ranged from
2 weeks to 9 years and 61% of children were younger than 1 year. The primary aim of the study
was to describe the clinical characteristics, incidence of complications, and management (pre-
admission and hospital) of the patients. The authors did not specify the total number of cases with
clinical dehydration, but overall only 7% were judged to be severely dehydrated. Pathogenic
organisms were isolated in the stools of 58% of children (125/215) with virus alone in 30%
(65/215). Among the viral pathogens, rotavirus was the most frequently isolated (83% of all
viruses). Bacteria alone were found in 14% of cases, with campylobacter and E. coli being the
most common. Cryptosporidium spp. were the most common parasites detected. [EL = 3]

A surveillance study reported viral agents isolated from clinical specimens in a regional public
59
health laboratory in the UK during the winter of 1999–2000. Altogether 3172 specimens (stool or
occasional vomit) of sporadic cases of gastroenteritis in children under the age of 7 years were sent
to the laboratory. Samples were received from general practitioners (34%), hospitals (56%) and
other public laboratories (9%) in the southwest of England and south Wales. Over the same period,
1360 specimens were also tested from 285 reported outbreaks of gastroenteritis, with 34% of
these specimens coming from the community and the rest from the hospitals. A viral aetiology was
confirmed in 37.7% of sporadic cases of gastroenteritis, with rotavirus being the most common viral
agent detected, in 21.6% (685/3172) of them. The other enteric viruses detected were norovirus
(10.3%), adenovirus (3.9%), astrovirus (3.1%) and calicivirus (0.2%). The prevalence of all the
enteric viral agents was reported to be higher in the specimens from the community compared
with the specimens from the hospitals. For the outbreaks, norovirus was the most common viral
agent isolated (in 63.9% of outbreaks), followed by rotavirus (3.9%), adenovirus (0.4%) and
astrovirus (0.4%). No viral agent was isolated in 32.6% of outbreaks. [EL = 3]
60
In another prospective study from a large hospital, stool samples of children (younger than
16 years) admitted to the hospital with a diagnosis of acute gastroenteritis or who developed

28