Purpose: The objective of this review was to 1) identify existing peer-reviewed literature on the severity and incidence of LTHO at least six months after acute STEC infection or post-diarrheal hemolytic uremic syndrome (HUS); 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. The entire literature from six major authors was also reviewed. 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 2,270 identified articles, 80 studies were included in the review. The majority of studies (57%) were retrospective reviews of patient records with no comparison group or systematic follow-up. Twenty-three (29%) were from one of two cohorts: the Walkerton Health Study and the Utah HUS Registry. After 5 to 10 years of follow-up, 20% to 30% of pediatric HUS cases showed signs of hypertension or reduced renal function. Other LTHO identified included neurological dysfunction, gastrointestinal disorders, diabetes/pancreatic injury and reactive arthritis.
Significance: Few systematic, prospective, population-based studies with control groups exist to inform our understanding of the risks of LTHOs after STEC infection. Much of the evidence comes from studies that were not designed to estimate risk. Population-based studies and meta-analyses are needed to better understand the incidence and risk of LTHO following STEC infection.