Purpose: The objective of this review was to 1) identify existing peer-reviewed literature on the severity and incidence of LTHO associated with human campylobacteriosis; 2) qualitatively evaluate the strength of the evidence, and 3) identify potential data gaps.
Methods: An extensive search of the online PubMed electronic database was conducted to identify primary research on LTHO from human case-control and cohort studies. LTHO were defined to be symptoms that persist more than six months after infection. Following a two-stage relevance screening, a full article review was conducted to qualitatively assess relevance and quality and extract data to be summarized.
Results: Of 2,224 identified articles, 30 studies were included in the review (12 case-control; 13 population cohort; 5 outbreak cohort). Eight studies (26%) did not report risk estimates for LTHO and seven (23%) examined multiple bacterial pathogens and could not provide results for Campylobacter alone. GBS and irritable bowel syndrome (IBS) were the most common LTHO examined; other LTHO included hypertension, renal impairment and reactive arthritis. Nine case-control studies reported 20% - 57% of GBS cases had evidence of prior Campylobacter infection while five studies found increased risk of IBS.
Significance: Few studies evaluate the LTHO of Campylobacter infection and those that do are limited in scope. Current literature provides evidence to support the existence of LTHOs but, beyond GBS, there is no clear understanding of the risk of disease.