Current epidemiology of hepatitis E virus infection in the United States: low seroprevalence in the National Health and Nutrition Evaluation Survey.

UNLABELLED: Analysis of the National Health and Nutrition Evaluation Survey (NHANES) 1988-1994 dataset found a relatively high seroprevalence (21%) of hepatitis E virus (HEV) infection in the U.S. general population. Using data obtained within the NHANES 2009-2010 survey, where a high performance assay for HEV was used, we estimated the weighted seroprevalence of HEV infection among U.S. individuals 6 years and older. We also evaluated factors associated with HEV seropositivity. A total of 8,814 individuals were included in the analysis. The median age of study participants was 37 years (interquartile range [IQR] 17-58 years), with 51.2% being female. The weighted national seroprevalence of HEV was 6% (95% confidence interval [CI] 5.1%-6.9%). About 0.5% of those with HEV had evidence of recent exposure (immunoglobulin M-positive). In the univariate analyses, factors associated with HEV seropositivity were increasing age (P-trend<0.001), birth outside of the U.S., Hispanic race, and "meat" consumption (>10 times/month). No significant association was observed with low socioeconomic status, water source, or level of education. In the multivariate analysis, only older age remained predictive of HEV seropositivity. CONCLUSION: The weighted national seroprevalence of HEV in the U.S. is much less than previously reported. Using data obtained with a high performance assay, the seroprevalence of HEV was estimated at 6.0% in the U.S. Based on these results, the seroprevalence of HEV is only one-third as high as previously reported.

Prevalence, trends, and risk factors for fecal incontinence in United States adults, 2005-2010.

BACKGROUND & AIMS: We investigated the prevalence of and trends and risk factors for fecal incontinence (FI) in the United States among non-institutionalized adults from 2005 to 2010. METHODS: We analyzed data from 14,759 participants in the U.S. National Health and Nutrition Examination Survey (49% women, 20 years or older) from 2005 to 2010 (the FI Severity Index was added in 2005-2006). FI was defined as accidental leakage of solid or liquid stool or mucus at least once in preceding month. Sampling weights were used to obtain estimates for the national population. Logistic regression was used to identify risk factors for FI. RESULTS: The prevalence of FI among non-institutionalized U.S. adults was 8.39% (95% confidence interval, 7.76-9.05). It was stable throughout the study period: 8.26% in 2005-2006, 8.48% in 2007-2008, and 8.41% in 2009-2010. FI resulted in release of liquid stool in most cases (6.16%). Prevalence increased with age from 2.91% among 20- to 29-year-old participants to 16.16% (14.15%-18.39%) among participants 70 years and older. Independent risk factors for FI included older age, diabetes mellitus, urinary incontinence, frequent and loose stools, and multiple chronic illnesses. FI was more common among women only when they had urinary incontinence. CONCLUSIONS: FI is a common problem among non-institutionalized U.S. adults. Its prevalence remained stable from 2005-2010. Diabetes mellitus and chronic diarrhea are modifiable risk factors. Future studies on risk factors for FI should assess for presence of urinary incontinence.