Epidemiology of gastroenteritis in Saudi Arabia.

In order to determine the aetiology and epidemiology of gastrointestinal infections in Saudi Arabia; viral, bacterial and parasitic causes of diarrhoea at a major referral centre were examined. Bacterial enteropathogens were found in 7.7% of patients; Salmonella species (51.7%) were found to be the most frequent pathogens followed by Campylobacter jejuni (28%) and Shigella species (14.9%). Clostridium difficile was also found in 9.5% of patients examined but no correlation could be found with presence of faecal leukocytes or pH. Susceptibility patterns of 15,467 isolates of Enterobacteriaceae to 14 antibiotics over 6 years showed that resistance increased in all the Enterobacteriaceae. Imipenem and ciprofloxacin were the only agents to remain active. Protozoan or metazoan parasites were detected in 27.8% of patients examined, the most common being Giardia lamblia and Hymenolopsis nana. Of the patients tested for viruses in stools, 14% had rotavirus, 8.5% adenovirus, 1.5% SRSVs and 0.3% coronavirus. Adenoviruses in stools were detected and serotyped for the first time in Saudi Arabia. Data were correlated with clinical history and serology which showed that immunosuppression was a major factor for onset of gastroenteritis. Type 40/41 were most prevalent followed by types 1,2,3, and 5. Most infections were in children under five years. Astroviruses were detected by PCR and gave an incidence of 1.5%. Rotavirus electropherotypes were determined by polyacrylamide gel electrophoresis and exhibited mostly the long electropherotype characteristic of group A subtype II. Environmental surfaces on a hospital ward were examined over a six month period in which rotavirus was found in 7% of sites tested and equated with areas involving most human activity and occurrence of rotavirus infections in patients. Diagnostic methods such as biotinylated DNA probe and latex agglutination (LA) were evaluated for rapid detection of enteric infections. LA was found to be suitable as a screening method but the DNA probe showed very low sensitivity and specificity for diagnostic use.