A high attack rate in households, lack of a common source of infection, and poor hygienic practices in households with > or = 2 cases suggest person-to-person transmission of HEV during this outbreak.

In October 2007, an epidemic of hepatitis E was suspected in Kitgum District of northern Uganda where no previous epidemics had been documented. This outbreak has progressed to become one of the largest hepatitis E outbreaks in the world. By June 2009, the epidemic had caused illness in >10,196 persons and 160 deaths.

An outbreak of hepatitis E virus (HEV) began in October 2007 in northern Uganda. To determine risk factors and sources for ongoing transmission, we conducted both a case-control study and an environmental investigation. A case patient was defined as having serologic evidence of HEV infection, whereas controls were seronegative. We identified risk factors for infection by univariable and multivariable analyses using conditional logistic regression. Several water sources were tested for HEV RNA. Among 112 cases and 145 controls, storage of drinking water in large-mouthed vessels (adjusted odds ratios [AOR] = 2.83; 95% confidence interval [CI] = 1.16-6.94) and washing hands in a group basin (AOR = 1.90; 95% CI = 1.07-3.38) were associated with HEV infection. HEV RNA was detected from communal hand-rinse and surface-water samples. The epidemiologic and environmental water-testing results suggest that household-level factors played an important role in the transmission of HEV-modalities that have been previously underappreciated.

Results from the first 3 years following RV1 introduction suggest substantial reductions of pediatric diarrheal disease as a result of vaccination. Our VE estimate is consistent with the observed rotavirus decrease and with efficacy estimates from elsewhere in sub-Saharan Africa.

Noroviruses and other viral pathogens are increasingly recognized as frequent causes of acute gastroenteritis (AGE). However, few laboratory-based data are available on the incidence of AGE caused by viral pathogens in the U.S. This study examined stool specimens submitted for routine clinical diagnostics from patients enrolled in Kaiser Permanente (KP) health plans in metro Portland, OR, and the Maryland, District of Columbia, and northern Virginia geographic areas to estimate the incidence of viral enteropathogens in these populations. Over a one-year study period, participating laboratories randomly selected stools submitted for routine clinical diagnostics for inclusion in the study along with accompanying demographic and clinical data. Selected stools were tested for norovirus, rotavirus, sapovirus, and astrovirus using standardized real-time RT-PCR protocols. Each KP site provided administrative data which were used in conjunction with previously published data on healthcare utilization to extrapolate pathogen detection rates into population-based incidence rates. A total of 1,099 specimens collected during August 2012 to September 2013 were included. Mean age of patients providing stool specimens was 46 years (range: 0–98 years). Noroviruses were the most common viral pathogen identified among patients with AGE (n = 63 specimens, 6% of specimens tested). In addition, 22 (2%) of specimens were positive for rotavirus; 19 (2%) were positive for sapovirus; and 7 (1%) were positive for astrovirus. Incidence of norovirus-associated outpatient visits was 5.6 per 1,000 person-years; incidence of norovirus disease in the community was estimated to be 69.5 per 1,000 person-years. Norovirus incidence was highest among children <5 years of age (outpatient incidence = 25.6 per 1,000 person-years; community incidence = 152.2 per 1,000 person-years), followed by older adults aged >65 years (outpatient incidence = 7.8 per 1,000 person-years; community incidence = 75.8 per 1,000 person-years). Outpatient incidence rates of rotavirus, sapovirus, and astrovirus were 2.0, 1.6, 0.6 per 1,000 person-years, respectively; community incidence rates for these viruses were 23.4, 22.5, and 8.5 per 1,000 person-years, respectively. This study provides the first age-group specific laboratory-based community and outpatient incidence rates for norovirus AGE in the U.S. Norovirus was the most frequently detected viral enteropathogen across the age spectrum with the highest rates of norovirus disease observed among young children and, to a lesser extent, the elderly. These data provide a better understanding of the norovirus disease burden in the United States, including variations within different age groups, which can help inform the development, targeting, and future impacts of interventions, including vaccines.

We determined hepatitis B virus (HBV) testing and vaccination levels and factors associated with testing and vaccination among Vietnamese- and Cambodian-Americans. We also examined factors associated with healthcare professional (HCP)-patient discussions about HBV. We analyzed 2006 Racial and Ethnic Approaches to Community Health (REACH) 2010 Risk Factor Survey data from four US communities. We used logistic regression to identify variables associated with HBV vaccination, testing, and HCP-patient discussions about HBV. Of the 2,049 Vietnamese- and Cambodian-American respondents, 60% reported being tested for HBV, 35% reported being vaccinated against hepatitis B, and 36% indicated that they had discussed HBV with a HCP. Cambodian-Americans were less likely than Vietnamese-Americans to have been tested for HBV, while respondents with at least a high school diploma were more likely to have been tested for HBV. Respondents born in the US, younger individuals, and respondents with at least some college education were more likely to have been vaccinated against hepatitis B. HBV testing and vaccination remain suboptimal among members of these populations. Culturally sensitive efforts that target Vietnamese- and Cambodian-Americans for HBV testing and vaccination are needed to identify chronic carriers of HBV, prevent new infections, and provide appropriate medical management. HCPs that serve these populations should be encouraged to discuss HBV with their patients.

Reports of hepatitis B virus (HBV) and hepatitis C virus (HCV) transmission associated with unsafe medical practices have been increasing in the United States. However, the contribution of healthcare exposures to the burden of new infections is poorly understood outside of recognized outbreaks. We conducted a case-control study at three health departments that perform enhanced viral hepatitis surveillance in New York and Oregon. Reported cases of symptomatic acute hepatitis B and hepatitis C occurring in persons 55 years of age from 2006 to 2008 were enrolled. Controls were identified using telephone directories and matched to individual cases by age group (55-59, 60-69, and 70 years) and residential postal code. Data collection covered exposures within 6 months before symptom onset (cases) or date of interview (controls). Fortyeight (37 hepatitis B and 11 hepatitis C) case and 159 control patients were enrolled. Case patients were more likely than controls to report one or more behavioral risk exposures, including sexual or household contact with an HBV or HCV patient, >1 sex partner, illicit drug use, or incarceration (21% of cases versus 4% of controls exposed; matched odds ratio [mOR] 5 7.1; 95% confidence interval [CI]: 2.1, 24.1). Case patients were more likely than controls to report hemodialysis (8% of cases; mOR 5 13.0; 95% CI: 1.5, 115), injections in a healthcare setting (58%; mOR 5 2.7; 95% CI: 1.3, 5.3), and surgery (33%; mOR 5 2.3; 95% CI: 1.1, 4.7). In a multivariate model, behavioral risks (adjusted OR [aOR] 5 5.4; 95% CI: 1.5, 19.0; 17% attributable risk), injections (aOR 5 2.7; 95% CI: 1.3, 5.8; 37% attributable risk), and hemodialysis (aOR 5 11.5; 95% CI: 1.2, 107; 8% attributable risk) were associated with case status. Conclusion: Healthcare exposures may represent an important source of new HBV and HCV infections among older adults. (HEPATOLOGY 2013;57:917-924)

Background Universal 2-dose varicella vaccination was recommended in 2006 to further reduce varicella disease burden. This study examined 2-dose varicella vaccine effectiveness (VE) and rash severity in the setting of school-associated varicella outbreaks. Methods A case control study was conducted from January 2010 to May 2011 in all West Virginia public schools. Clinically diagnosed cases from varicella outbreaks were matched with classmate controls. Vaccination information was collected from school, health department and healthcare provider immunization information systems. Results Among the 133 cases and 365 controls enrolled, VE against all varicella was 83.2% [95% confidence interval (CI): 69.2%–90.8%] for 1-dose of varicella vaccine and 93.9% (95% CI: 86.9%–97.1%) for 2-dose; the incremental VE (2-dose vs. 1-dose) was 63.6% (95% CI: 32.6%–80.3%). In preventing moderate/severe varicella, 1-dose varicella vaccine was 88.2% (95% CI: 72.7%– 94.9%) effective, and 2-dose vaccination was 97.5% (95% CI: 91.6%–99.2%) effective, with the incremental VE of 78.6% (95% CI: 40.9%–92.3%). One-dose VE declined along with time since vaccination (VE = 93.0%, 88.0% and 81.8% in <5, 5–9 and ≥10 years after vaccination, P = 0.001 for trend). Both 1- and 2-dose breakthrough cases had milder rash than unvaccinated cases (<50 lesion: 24.6%, 49.1% and 70.0% in unvaccinated, 1-dose and 2-dose cases, P < 0.001), and no severe disease was found in 2-dose cases. Conclusions Two-dose varicella vaccination is highly effective and confers higher protection than a 1-dose regimen. High 2-dose varicella vaccination coverage should maximize the benefits of the varicella vaccination program and further reduce varicella disease burden in the United States.