title: Etiology of Appendicitis in Children: The Role of Bacterial and Viral Pathogens.
abstract: BACKGROUND
  Although acute appendicitis is the most common cause for abdominal surgery in children, its etiology is still largely unknown. The aim of this study was to evaluate the role of bacterial and viral pathogens for the etiology of appendicitis in children.
  
  
  METHODS
  Between 2000 and 2010, 277 children underwent appendectomy in our institution. On this collective, a retrospective study was performed on to identify the presence of bacterial or viral pathogens.
  
  
  RESULTS
  Intraoperatively, 39% of cases showed acute, 9% of cases chronic, and 41% of cases ulcerous inflammation. Bowel perforation was found in 7% of cases and four percent of the children had no inflammation of the appendix at all. Escherichia coli was the predominant bacterium with an incidence of 27.4%, followed by streptococci (9.8%). Concerning viral pathogens, adenovirus was the most common with an incidence of 5.4% followed by rotavirus (4.7%). Significant correlations between histopathological findings and present pathogens were found: in cases of bowel perforation there were significantly more infections with E. coli bacteria (32.2%, p < .001), streptococci (12.2%, p < 0.001), and Pseudomonas aeruginosa (6.7%, p < .001) whereas chronic inflammations were accompanied with a significantly elevated rate of yersinia infections (2.5%, p = .016). Acute inflammations were significantly more often associated with campylobacter (1.7%, p = .011) and oxyures infections (6.1%, p < .001). In relation to the patients' age, a significant accumulation of different pathogens was observed. CRP- and leukocyte counts showed differences between viral and bacterial inflammations.
  
  
  CONCLUSIONS
  Our data indicates that appendicitis in children might be triggered by bacterial and viral pathogens and that the type of pathogen directly correlates with patient age, type of inflammation, and level of inflammation values. To confirm and further evaluate these findings, additional studies need to be conducted.
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: I
authors.initials: I
authors.lastname: Richardsen
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: D S
authors.initials: DS
authors.lastname: Schöb
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: T F
authors.initials: TF
authors.lastname: Ulmer
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: G
authors.initials: G
authors.lastname: Steinau
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: U P
authors.initials: UP
authors.lastname: Neumann
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: C D
authors.initials: CD
authors.lastname: Klink
authors.affiliation: a Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital , Aachen , Germany.
authors.forename: A
authors.initials: A
authors.lastname: Lambertz
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000367:Age Factors; D001062:Appendectomy; D001064:Appendicitis / Q000209:etiology / Q000382:microbiology* / Q000601:surgery / Q000821:virology*; D001419:Bacteria / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007249:Inflammation / Q000097:blood / Q000382:microbiology* / Q000821:virology*; D007416:Intestinal Perforation / Q000382:microbiology*; D008297:Male; D012189:Retrospective Studies; D014780:Viruses / Q000302:isolation & purification
keywords: Appendicitis; children; etiology; parasites; viral and bacterial pathogens