Analysis Of Risk Factors For Possible Foodborne Transmission Of Clostridium Difficile Infection

Objective:To monitor the prevalence of Clostridium difficile infection(CDI) in hospitalized children with diarrhea,investigate Clostridium difficile environmental contamination in hospital,identify the related factors of CDI in children,and explore the possible foodborne transmission of clostridium difficile. Meanwhile,analysing the pathogens’ distribution of pediatric diarrhea to recognize the present situation of mixed infection with Clostridium difficile and other gastrointestinal pathogens.Methods:1. A total of 209 hospitalized pediatric patients with diarrhea in Soochow University Affiliated Children’s Hospital were recruited as subjects,from June to December 2013.The stool specimens were collected to perform anaerobic enrichment culture, then the bacterial genomic DNA extraction kit was used to extract strain DNA.Real-time PCR assays targeting housekeeping gene tpi and toxin tcd A/ tcd B genes of C. difficile were performed to screen positive stool specimens and detect pathogenicity of C.difficile.Based on the results of colstridium difficile culture and the detection of Clostridium difficile toxin genes,patients with diarrhea and positive Clostridium difficile toxin gene test were diagnosed with CDI.2. Data were collected by self-designed questionnaire and electronic medical record system in Soochow University Affiliated Children’s Hospital and were further entered into database using Epidata3.1 software.The statistical differences between subjects with and without CDI were compared to explore the relevant factors using SPSS17.0 software and level of significance wae set at P < 0.05.3. A total of 120 environmental specimens were collected in the Gastroenterology Ward,including surface swabs from toilet, faucet, door handles, accompanying family members’ hands, sick bed guardrail five parts.Anaerobic enrichment culture were performed on the specimens to raise target bacteria.Further strain DNA wereextracted,toxigenic colstridium difficile were detected by PCR,4. Other enteric pathogenic bacterium were isolated and identified by feces culture,while pathogenic viruses were detected by corresponding kits.Based on the detecting results,microbiota composition in the pediatric diarrhea were investigated meanwhile mixed infection of Clostridium difficile positive diarrhea with other enteric pathogens were analyzed.Results:1. Among 209 children with diarrhea, the overall positive rate of Clostridium difficile was 23.0%(48/209),in which toxigenic Clostridium difficile(toxin gene A/B positive) was32 cases.The incidence of Clostridium difficile infection was 15.3%(32/209) according to the diagnostic criteria of Clostridium difficile infection.2. The results of logistic regression analysis for risk factors of Clostridium difficile infection showed that ≤ 6 months old might be a protective factor,the difference was statistically significant(p=0.019, OR=0.221).Analysis of the other related factors in children with Clostridium difficile infection showed that three indices include diarrhea duration before admission(p=0.007, OR=3.395), watery stool(p=0.013, OR=5.011) and fever(p=0.039, OR=2.486) had significant difference.3. Total 23 cases(23/31,74.2%) with CDI belonged to community acquiredClostridium difficile infection(CA-CDI),as they suffered diarrhea in two days after admission and no hospitalization experience 6 weeks before admission.Among 120 environmental specimens collected in the hospital, only 1 case collected from the toilet edge found Clostridium difficile and B toxin positive.4. In 209 cases of diarrhea children, pathogenic microorganisms were detected in 127cases(60.8%),including the existence of complicated infection in 30 cases(30/127,23.6%).Virus infection rate was 72.8%, in which rotavirus was the most common cause of gastrointestinal infections, followed by calicivirus; bacterial infection accounted for 27.2%,in which Clostridium difficile ranked first, followed by salmonella.Among mixed infection with other pathogens, rotavirus(23/30,76.7%) was found most frequent, followed by calicivirus(17/30,56.7%) and Clostridium difficile(16/30,53.3%).Conclusions:1. Clostridium difficile infection rate in diarrhea children in Suzhou was high with frequently mixed infection.Results suggested the increases in incidence and complexity ofClostridium difficile infection in Suzhou and the surveillance systems are necessary to monitor trends and inform public health actions.2. Among children with CDI,the proportion of CA-CDI and children feeding supplementary food were relatively high, suggesting the possibility of the foodborne transmission and more attention should be payed when feeding infants older than 6 months old to prevent Clostridium difficile infection via hand/mouth transmission from the contaminated environment..3. Clinical symptoms including watery stools and fever symptoms were significant in children with CDI,which may assist to make fast clinical diagnosis of Clostridium difficile infection.