Dr Alder and colleagues have attempted to clarify the causative agents for appendicitis by analyzing the NHDS for associations between rates of appendicitis and several infectious diseases. They concluded there was no association between intestinal infections and rotavirus with appendicitis but did see a parallel year-to-year peak incidence with nonperforated appendicitis and influenza.
While this is an interesting concept, it does not appear to implicate influenza virus as a causative agent for appendicitis. Certainly concerning is that the peak of influenza is in the winter months, which is not replicated in appendicitis. Also, appendicitis is more often a disease of the young and influenza a disease of the older population, which goes against influenza as a proximate agent. Additionally, the study relies on hospital discharge data, which are likely much more complete for appendicitis as this is a disease necessitating hospitalization. The vast majority of patients with a viral illness are not hospitalized, and many likely do not even seek medical attention. Certainly this makes comparison onerous.
Britt RC. Still Looking for Reasons in AppendicitisComment on “Association of Viral Infection and Appendicitis”. Arch Surg. 2010;145(1):71. doi:10.1001/archsurg.2009.251