Temporal and Genotypic Associations of Sporadic Norovirus Gastroenteritis and Reported Norovirus Outbreaks in Middle Tennessee, 2012-2016.

BACKGROUND: In the United States, surveillance of norovirus gastroenteritis is largely restricted to outbreaks, limiting our knowledge of the contribution of sporadic illness to the overall impact on reported outbreaks. Understanding norovirus transmission dynamics is vital for improving preventive measures, including norovirus vaccine development. METHODS: We analyzed seasonal patterns and genotypic distribution between sporadic pediatric norovirus cases and reported norovirus outbreaks in middle Tennessee. Sporadic cases were ascertained via the New Vaccine Surveillance Network in a single county, while reported norovirus outbreaks from 7 middle Tennessee counties were included in the study. We investigated the predictive value of sporadic cases on outbreaks using a 2-state discrete Markov model. RESULTS: Between December 2012 and June 2016, there were 755 pediatric sporadic norovirus cases and 45 reported outbreaks. Almost half (42.2%) of outbreaks occurred in long-term care facilities. Most sporadic cases (74.9%) and reported outbreaks (86.8%) occurred between November and April. Peak sporadic norovirus activity was often contemporaneous with outbreak occurrence. Among both sporadic cases and outbreaks, GII genogroup noroviruses were most prevalent (90.1% and 83.3%), with GII.4 being the dominant genotype (39.0% and 52.8%). The predictive model suggested that the 3-day moving average of sporadic cases was positively associated with the probability of an outbreak occurring. CONCLUSIONS: Despite the demographic differences between the surveillance populations, the seasonal and genotypic associations between sporadic cases and outbreaks are suggestive of contemporaneous community transmission. Public health agencies may use this knowledge to expand surveillance and identify target populations for interventions, including future vaccines.

Large Outbreak of Hepatitis C Virus Associated With Drug Diversion by a Healthcare Technician.

Background: In May 2012, the New Hampshire (NH) Division of Public Health Services (DPHS) was notified of 4 persons with newly diagnosed hepatitis C virus (HCV) infection at hospital X. Initial investigation suggested a common link to the hospital cardiac catheterization laboratory (CCL) because the infected persons included 3 CCL patients and a CCL technician. NH DPHS initiated an investigation to determine the source and control the outbreak. Methods: NH DPHS conducted site visits, case patient and employee interviews, medical record and medication use review, and employee and patient HCV testing using enzyme immunoassay for anti-HCV, reverse-transcription polymerase chain reaction for HCV RNA, nonstructural 5B (NS5B) and hypervariable region 1 (HVR1) sequencing, and quasispecies analysis. Results: HCV HVR1 analysis of the first 4 cases confirmed a common source of infection. HCV testing identified 32 of 1074 CCL patients infected with the outbreak strain, including 3 patients coinfected with >1 HCV strain. The epidemiologic investigation revealed evidence of drug diversion by the HCV-infected technician, evidenced by gaps in controlled medication control, higher fentanyl use during procedures for confirmed cases, and building card key access records documenting the presence of the technician during days when transmission occurred. The employee's status as a traveling technician led to a multistate investigation, which identified additional cases at prior employment sites. Conclusions: This is the largest laboratory-confirmed drug diversion-associated HCV outbreak published to date. Recommendations to reduce drug diversion risk and to conduct outbreak investigations are provided.

Per- and polyfluoroalkyl substance (PFAS) exposure assessment in a community exposed to contaminated drinking water, New Hampshire, 2015.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in manufacturing that resist environmental degradation, can leach into drinking water, and bioaccumulate in tissues. Some studies have shown associations with negative health outcomes. In May 2014, a New Hampshire public drinking water supply was found to be contaminated with PFAS from a former U.S. Air Force base. OBJECTIVES: We established a serum testing program to assess PFAS exposure in the affected community. METHODS: Serum samples and demographic and exposure information were collected from consenting eligible participants. Samples were tested for PFAS at three analytical laboratories. Geometric means and 95% confidence intervals were calculated and analyzed by age and exposure variables. RESULTS: A total of 1578 individuals provided samples for PFAS testing; >94% were found to have perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) detectable in serum. Geometric mean serum concentrations of PFOS, PFOA, and PFHxS were 8.6 µg/L (95% CI:8.3-8.9), 3.1 µg/L (95% CI: 3.0-3.2), and 4.1 µg/L (95% CI: 3.9-4.3), respectively, which were statistically higher than the general U.S. POPULATION: Significant associations were observed between PFAS serum concentrations and age, time spent in the affected community, childcare attendance, and water consumption. CONCLUSIONS: PFOS, PFOA, and PFHxS were found in significantly higher levels in the affected population, consistent with PFAS drinking water contamination. Given increased recognition of PFAS contamination in the U.S, a coordinated national response is needed to improve access to biomonitoring and understand health impacts.

Use of Digital Pens for Rapid Epidemiologic Data Collection During a Foodborne Outbreak Investigation.

OBJECTIVE: Public health investigations require rapid assessment, response, and initiation of control measures. In 2012, the New Hampshire Department of Health and Human Services used digital pens to rapidly acquire epidemiologic data during a gastrointestinal illness outbreak. METHODS: Menus were obtained and a standard questionnaire was administered to exposed persons using digital pens. Questionnaire data were downloaded into an electronic file for analysis. RESULTS: Sixty-nine (74%) of 93 exposed persons completed a questionnaire. Of 6389 data entries made on digital paper, 218 (3%) required correction; of these, 201 (92%) involved a free-form variable and 17 (8%) involved a check-box variable. Digital pens saved an estimated 5 to 6 hours of data-entry time. CONCLUSIONS: This outbreak provided an opportunity to assess the value of digital pens for decreasing data-entry burden and allowing more timely data analysis in an emergent setting. Depending on the size of the outbreak and complexity of the survey, there is likely a threshold when use of digital pens would provide a clear benefit to outbreak response. As new technology becomes available for use in emergency preparedness settings, public health agencies must continuously review and update response plans and evaluate investigation tools to ensure timely disease control and response activities.

Human outbreak of Salmonella Typhimurium associated with exposure to locally made chicken jerky pet treats, New Hampshire, 2013.

Pet treats and pet food can be contaminated with Salmonella and other pathogens, though they are infrequently implicated as the source of human outbreaks. In 2013, the New Hampshire Department of Health and Human Services investigated a cluster of Salmonella Typhimurium infections associated with contaminated locally made pet treats. Case-patients were interviewed with standardized questionnaires to assess food, animal, and social histories. Laboratory and environmental investigations were conducted, including testing of clinical specimens, implicated product, and environmental swabs. Between June and October 2013, a total of 43 ill persons were identified. Sixteen patients (37%) were hospitalized. Among 43 case-patients interviewed, the proportion exposed to dogs (95%) and pet treats (69%) in the 7 days prior to illness was statistically higher than among participants in a U.S. population-based telephone survey (61%, p<0.0001 and 16%, p<0.0001, respectively). On further interview, 38 (88%) reported exposure to Brand X Chicken Jerky, the maker of Brand X chicken jerky, or the facility in which it was made. Product testing isolated the outbreak strain from four of four Brand X Chicken Jerky samples, including an unopened package purchased at retail, opened packages collected from patient households, and unpackaged jerky obtained from the jerky maker. A site visit revealed inadequate processing of the chicken jerky, bare-hand contact with the finished product prior to packaging, and use of vacuum-sealed packaging, which may have enabled facultative anaerobic bacteria to proliferate. Seven (78%) of nine environmental swabs taken during the site visit also yielded the outbreak strain. Brand X Chicken Jerky was voluntarily recalled on September 9, 2013. Consumers should be made aware of the potential for locally made products to be exempt from regulation and for animals and animal food to carry pathogens that cause human illness, and be educated to perform hand hygiene after handling pet food or treats.

Effects of mutations in SGS1 and in genes functionally related to SGS1 on inverted repeat-stimulated spontaneous unequal sister-chromatid exchange in yeast.

BACKGROUND: The presence of inverted repeats (IRs) in DNA poses an obstacle to the normal progression of the DNA replication machinery, because these sequences can form secondary structures ahead of the replication fork. A failure to process and to restart the stalled replication machinery can lead to the loss of genome integrity. Consistently, IRs have been found to be associated with a high level of genome rearrangements, including deletions, translocations, inversions, and a high rate of sister-chromatid exchange (SCE). The RecQ helicase Sgs1, in Saccharomyces cerevisiae, is believed to act on stalled replication forks. To determine the role of Sgs1 when the replication machinery stalls at the secondary structure, we measured the rates of IR-associated and non-IR-associated spontaneous unequal SCE events in the sgs1 mutant, and in strains bearing mutations in genes that are functionally related to SGS1. RESULTS: The rate of SCE in sgs1 cells for both IR and non-IR-containing substrates was higher than the rate in the wild-type background. The srs2 and mus81 mutations had modest effects, compared to sgs1. The exo1 mutation increased SCE rates for both substrates. The sgs1 exo1 double mutant exhibited synergistic effects on spontaneous SCE. The IR-associated SCE events in sgs1 cells were partially MSH2-dependent. CONCLUSIONS: These results suggest that Sgs1 suppresses spontaneous unequal SCE, and SGS1 and EXO1 regulate spontaneous SCE by independent mechanisms. The mismatch repair proteins, in contradistinction to their roles in mutation avoidance, promote secondary structure-associated genetic instability.