Cameron W, Clementson D, D.
J. Inf. Diseases. 1991. : IBIMA Publishing Abstract
OBJECTIVE: To measure the proportion of nosocomial diarrhea cases associated with Salmonella and Shigella species. DESIGN: Prospective 6-month survey. SETTING: Tertiary care center in a developing country. PATIENTS: Pediatric and adult patients admitted with the previous 24 hours and all consenting adult or pediatric medical patients with nosocomial diarrhea. OUTCOME MEASURES: Prevalence of Salmonella and Shigella species isolated from rectal swabs at admission and among subjects with nosocomial diarrhea. RESULTS: Salmonella species and Shigella species were isolated from 3.0% and 2.5%, respectively, of 667 patients screened on admission. All admission Salmonella isolates were identified in children under 13 years of age; Shigella prevalence was similar for children and adults. Children with Salmonella at admission were significantly older and more likely to have diarrhea, fever, and some indicators of malnutrition than those from whom Salmonella was not isolated. Salmonella and Shigella were isolated from rectal cultures in 36 (10%) and 9 (2.5%) of 360 nosocomial gastroenteritis cases, respectively. Nosocomial cases occurred equally in adults and children. In adults, nosocomial Salmonella acquisition was associated with sharing a room with a diarrhea patient and previous institutionalization. In children, it was associated with recent antimicrobial therapy, crowding at home, and age between 6 months and 6 years. Nine (41%) of 22 nosocomial Salmonella cases in adults occurred in patients with human immunodeficiency virus-type 1 (HIV-1) infection, while none of 79 HIV-1-positive patients had Salmonella isolated at admission. CONCLUSIONS: Salmonella is a frequent cause of nosocomial gastroenteritis in this tertiary care institution in a developing country. Risk factors appear to differ for children and adults, and HIV-1-infected subjects may be at increased risk of acquisition. Control measures feasible for the limited resources available to such institutions require evaluation. PIP: Researchers analyzed data on 667 patients admitted between March 9 and September 14, 1988 to the Kenyatta National Hospital in Nairobi, Kenya to verify the contribution of Salmonella and Shigella species to hospital acquired infections and to identify factors associated with admission and nosocomial infection. Laboratory personnel isolated Salmonella and Shigella in 12.5% (10% and 2.5% respectively) of the 360 patients with nosocomial diarrhea. Their overall prevalence was 3% and 2.5% respectively. These 2 bacteria were isolated from rectal swabs from 19 of the 27 hospital units. Most of the isolates were restricted to 5 units. All of the Salmonella isolates at admission were children under 13 years old (3.6% of 556 children). Shigella prevalence at admission was 2.5% for children and 3.6% for adults. The risk of nosocomial diarrhea caused by these 2 bacteria was much greater in children older than 6 months and younger than 6 years than in children of other ages (odds ratio [OR]=21.7; p=.006). The most significant variables which independently affected nosocomial diarrhea caused by these bacteria in children were recent antimicrobial therapy (OR=26.4; p=.001) and living in crowded homes (OR=1.2; p=.02). Another determinant was poor hair color indicating malnutrition (p=.03). Even though there were no significant differences between adults with nosocomial diarrhea caused by these bacteria and those with no nosocomial diarrhea, sharing a room with people with diarrhea, being in the hospital within the last 30 days, and being HIV-1 positive were factors that almost reached significance. In fact, 9 of their 22 (41%) adults with positive cultures of Salmonella were HIV=1 positive yet Salmonella was not isolated from any of the 70 HIV-1 positive patients at admission. Salmonella contributed greatly to nosocomial diarrhea at this hospital. The hospital should evaluate and redesign its control measures within available limited resources.