Validation of Health Event Capture in the Marshfield Epidemiologic Study Area

Reduced effectiveness of repeat influenza vaccination: distinguishing among within-season waning, recent clinical infection, and subclinical infection

Studies have reported that prior-season influenza vaccination is associated with higher risk of clinical influenza infection among vaccinees. This effect might arise from incomplete consideration of within-season waning and recent infection. Using data from the US Flu Vaccine Effectiveness (VE) Network (2011-2012 to 2018-2019 seasons), we found that repeat vaccinees were vaccinated earlier in a season by one week. After accounting for waning VE, repeat vaccinees were still more likely to test positive for A(H3N2) (OR=1.11, 95%CI:1.02-1.21) but not for influenza B or A(H1N1). We found that clinical infection influenced individuals' decision to vaccinate in the following season while protecting against clinical infection of the same (sub)type. However, adjusting for recent clinical infections did not strongly influence the estimated effect of prior-season vaccination. In contrast, we found that adjusting for subclinical infection could theoretically attenuate this effect. Additional investigation is needed to determine the impact of subclinical infections on VE.

Longitudinal dynamics of farmer and livestock nasal and faecal microbiomes and resistomes

Globally, half a billion people are employed in animal agriculture and are directly exposed to the associated microorganisms. However, the extent to which such exposures affect resident human microbiomes is unclear. Here we conducted a longitudinal profiling of the nasal and faecal microbiomes of 66 dairy farmers and 166 dairy cows over a year-long period. We compare farmer microbiomes to those of 60 age-, sex- and ZIP code-matched people with no occupational exposures to farm animals (non-farmers). We show that farming is associated with microbiomes containing livestock-associated microbes; this is most apparent in the nasal bacterial community, with farmers harbouring a richer and more diverse nasal community than non-farmers. Similarly, in the gut microbial communities, we identify more shared microbial lineages between cows and farmers from the same farms. Additionally, we find that shared microbes are associated with antibiotic resistance genes. Overall, our study demonstrates the interconnectedness of human and animal microbiomes.

Modeling longitudinal oral health status and pneumonia risk: secondary data analyses of an integrated dental-medical cohort

BACKGROUND

Mounting evidence indicates potential associations between poor oral health status (OHS) and increased pneumonia risk. Relative pneumonia risk was assessed in the context of longitudinally documented OHS.

METHODS

Electronic medical/dental patient data captured from 2007 through 2019 were retrieved from the integrated health records of Marshfield Clinic Health Systems. Participant eligibility initiated with an assessment of OHS, stratified into the best, moderate, or worst OHS groups, with the additional criterion of 'no pneumonia diagnosis in the past 90 days'. Pneumonia incidence was longitudinally monitored for up to 1 year from each qualifying dental visit. Models were assessed, with and without adjustment for prior pneumonia incidence, adjusted for smoking and subjected to confounding mitigation attributable to known pneumonia risk factors by applying propensity score analysis. Time-to-event analysis and proportional hazard modeling were applied to investigate relative pneumonia risk over time among the OHS groups.

RESULTS

Modeling identified associations between any incident pneumonia subtype and 'number of missing teeth' (p < 0.001) and 'clinically assessed periodontal status' (p < 0.01), which remained significant following adjustment for prior pneumonia incidence and smoking. The hazard ratio (HR) for 'any incident pneumonia' in the best OHS group for 'number of missing teeth' was 0.65, 95% confidence interval (CI) [0.54 - 0.79] (unadjusted) and 0.744, 95% CI [0.61 - 0.91] (adjusted). The HR for 'any incident pneumonia' in the best 'clinically assessed periodontal status' group was 0.72, 95% CI [0.58 - 0.90] (unadjusted) and 0.78, 95% CI [0.62 - 0.97] (adjusted).

CONCLUSION/CLINICAL RELEVANCE

Poor OHS increased pneumonia risk. Proactive attention of medical providers to patient OHS and health literacy surrounding oral-systemic disease association is vital, especially in high-risk populations.

Dairy Farm Work and Protection from Gastrointestinal Illness

Gastrointestinal (GI) disorders are a major public health burden in the United States. Due to close contact with animals, farmers may be a high risk subgroup for acute GI infections, though some studies suggest farm work is actually protective against GI illness. The purpose of this study was to examine associations between dairy farm work and GI symptoms over 3 years. A prospective, matched cohort study was used that included 70 adult dairy farm workers and 74 matched (age, gender, ZIP code) non-farm participants from central Wisconsin. The outcome was mean GI symptom scores for abdominal pain, diarrhea, constipation, dyspepsia, nausea, and reflux, per the 23-item Gastrointestinal Symptoms Severity Index (GISSI). After adjustment for potential confounding variables, linear regression results indicated dairy farm workers had significantly lower GISSI scores for abdominal pain (mean±SE = 4.3 ± 1.1 dairy vs. 7.6 ± 1.1 non-farm, p = .047), diarrhea (3.2 ± 1.0 dairy vs. 7.0 ± 1.0 non-farm, p = .010), constipation (2.0 ± 0.8 dairy vs. 6.6 ± 0.8 non-farm, p < .001), and dyspepsia (2.0 ± 0.6 dairy vs. 3.9 ± 0.5 non-farm, p = .026). Working on a dairy farm was associated with significantly less frequent and severe GI illness symptoms in adults. Future research should identify underlying causal pathways, including possible farm animal exposures, that influence beneficial gut microbiota that could inform therapeutic remedies to help prevent clinical GI disorders.

Regional surveillance of medically-attended farm-related injuries in children and adolescents

Purpose

Due to numerous environmental hazards such as heavy machinery and large livestock, youth who live and work on farms are at high risk of injury, disability, and death. This study described a regional surveillance system for monitoring farm-related injuries in children and adolescents. As the risk of farm-related injuries are not exclusive to farm residents, trends in farm-related injuries over the previous 5 years were reported and compared between children/adolescents who did and did not live on farms in north-central Wisconsin.

Methods

A retrospective cohort of child and adolescent patients of the Marshfield Clinic Health System was assembled. Incident farm-related injuries, including from agricultural work or other activities in a farm environment, were extracted from medical records from 2017 through 2021. Generalized linear models were created to compare age- and sex-adjusted farm-related injury rates by year.

Results

There were 4,730 (5%) in-farm and 93,420 (95%) out-farm children and adolescents in the cohort. There were 65 incident farm-related injury cases in the in-farm group and 412 in the out-farm group. The annual incidence rate of farm-related injuries was higher in the in-farm group, but changes during the 5-year timeframe were not significant in either group. In the in-farm group, rates ranged from a high of 61.8 [95% confidence interval (CI): 38.3, 94.5] incident farm-related injuries per 10,000 children/adolescents in 2017 to a low of 28.2 (13.5, 51.9) injuries per 10,000 children/adolescents in 2018. In the out-farm group, rates ranged from 10.7 (8.3, 13.6) to 16.8 (13.7, 20.5) incident farm-related injuries per 10,000 children/adolescents per year between 2017 and 2021. The in-farm group had a higher proportion of injured males and heavy machinery injuries, while the out-farm group had more all-terrain vehicle injuries and pesticide poisonings.

Conclusion

Farm residency remains hazardous for children and adolescents, as injury rates were three times higher in the in-farm group and remained stable over 5 years. All-terrain vehicle injuries were high in both groups, and should be a priority in rural safety interventions. With additional adaptations to other states, this surveillance model could be scaled across other healthcare systems.

Burden of medically attended influenza infection and cases averted by vaccination - United States, 2016/17 through 2018/19 influenza seasons

BACKGROUND

Epidemics of seasonal influenza vary in intensity annually, and influenza vaccine effectiveness (VE) fluctuates based in part on antigenic match to circulating viruses. We estimated the incidence of influenza and influenza cases averted by vaccination in four ambulatory care sites in the United States, during seasons when overall influenza VE ranged from 29% to 40%.

METHODS

We conducted active surveillance for influenza at ambulatory care settings at four sites within the United States Influenza Vaccine Effectiveness Network. We extrapolated the total number of influenza cases in the source populations served by these organizations based on incidence of medically attended acute respiratory illness in the source population and influenza test results in those actively tested for influenza. We estimated the number of medically attended influenza cases averted based on incidence, vaccine coverage, and VE.

RESULTS

From 2016/17 through 2018/19, incidence of ambulatory visits for laboratory-confirmed influenza ranged from 31 to 51 per 1,000 population. Incidence was highest in children aged 9-17 years (range, 56 to 81 per 1,000) and lowest in adults aged 18-49 years (range, 23-32 per 1,000). Medically attended cases averted by vaccination ranged from a high of 46.6 (95 % CI, 12.1- 91.9) per 1,000 vaccinees in children aged 6 months to 8 years, to a low of 6.9 (95 % CI, -5.1- 27.3) per 1,000 vaccinees in adults aged ≥ 65 years.

DISCUSSION

Even in seasons with low vaccine effectiveness for a particular virus subtype, influenza vaccines can still lead to clinically meaningful reductions in ambulatory care visits for influenza.

Sex hormones, body mass index, and related comorbidities associated with developing Sjögren's disease: a nested case-control study

OBJECTIVE

Sjögren's disease (SjD), a highly female predominant systemic autoimmune disease, peaks in perimenopause. Prior studies lack details on timing or type of sex hormone exposure. We examined SjD risk using endogenous and exogenous hormone exposure and related comorbidities.

METHODS

We performed a retrospective case-control study of adult women, nested within a population cohort. Cases had SjD diagnosed by a rheumatology provider or two SjD diagnoses from a non-rheumatology provider with a positive anti-SSA antibody or salivary gland biopsy. Cases were age-matched to three SjD-free controls. We calculated modified composite estrogen scores (mCES) and collected demographics, comorbidities, and endogenous and exogenous hormone exposures. Risk ratios were adjusted for demographics.

RESULTS

Of 546 SjD cases and 1637 age-matched controls, mCES was not significantly associated with SjD in adjusted models. The top individual hormone exposures associated with SjD included estrogen replacement therapy (ERT; RR 1.78 [95% CI 1.47-2.14]), polycystic ovarian syndrome (1.65 [1.28-2.12]), and hysterectomy without bilateral oophorectomy (1.51 [1.13-2.03]). We identified comorbidities preceding SjD including fibromyalgia, pulmonary disease, diabetes, lymphoma, osteoporosis, peripheral vascular disease, and renal disease. Taking comorbidities into account, we developed a predictive model for SjD that included fibromyalgia (2.50 [1.93-3.25]), osteoporosis (1.84 [1.27-2.66]), hormone replacement therapy (HRT) (1.61 [1.22-2.12]), diabetes (0.27 [0.13-0.50]), and body mass index (BMI) (0.97 [0.95-0.99]).

CONCLUSIONS

We report a novel algorithm to improve identifying patients at risk for SjD and describe sex hormone association with SjD. Finally, we report new comorbidities associated with SjD decrease, BMI and diabetes, and increase, lymphoma and osteoporosis.. Key Points •Given female predominance and typical perimenopausal onset, sex hormones should be considered when studying comorbidities in Sjögren's disease. •The top exposures associated with developing Sjögren's disease included fibromyalgia, osteoporosis, and use of hormone replacement therapy. Possible protective factors included prior diabetes and higher body mass index. •We used our newly identified exposures to generate a predictive algorithm, which has potential to improve diagnosis and pathogenic insights into Sjögren's disease.

Hydrochlorothiazide use, sun exposure, and risk of keratinocyte cancer

Background

Keratinocyte cancer (KC) rates are increasing in the U.S., particularly in older age groups. Use of hydrochlorothiazide (HCTZ), due to its photosensitizing properties, and high sun exposure are two known NMSC risk factors, but their synergistic effects are undetermined. The purpose of this study was to examine the development of NMSC between adults who did and did not use HCTZ, as well as those with high and low sun exposure.

Methods

A retrospective case–control sample was assembled from adult patients in north-central Wisconsin (USA). Duration of HCTZ use and occupational sun exposure were extracted from electronic health records, along with a linked survey of lifetime sun exposure.

Results

There were 333 cases and 666 controls in the analytical sample. A significant main effect was observed for HCTZ duration in the full sample. Under low sun exposure, the odds of NMSC was 14% greater for each additional year of HCTZ use (aOR = 1.14 [1.11, 1.18], p < 0.001). In a sensitivity analysis of participants age 70 years and over, there was a borderline significant (p = 0.086) HCTZ use by high sun exposure interaction, suggesting modestly increased HCTZ risk in older, high sun exposure adults.

Conclusions

Consistent with prior studies, longer duration of HCTZ use was a predictor of NMSC in north-central Wisconsin adults. NMSC may be accelerated in HCTZ users with outdoor lifestyles, but future studies should attempt to further disaggregate specific effects of sun exposure time, HCTZ duration, and age on NMSC development.

mRNA COVID-19 vaccine effectiveness against SARS-CoV-2 infection in a prospective community cohort, rural Wisconsin, November 2020 to December 2021

Reduced COVID-19 vaccine effectiveness (VE) has been observed with increasing predominance of SARS-CoV-2 Delta (B.1.617.2) variant. Two-dose VE against laboratory-confirmed SARS-CoV-2 infection (symptomatic and asymptomatic) was estimated using Cox proportional hazards models with time-varying vaccination status in a prospective rural community cohort of 1266 participants aged ≥12 years. Between November 3, 2020 and December 7, 2021, VE was 56% for mRNA COVID-19 vaccines overall, 65% for Moderna, and 50% for Pfizer-BioNTech. VE when Delta predominated (June to December 2021) was 54% for mRNA COVID-19 vaccines overall, 59% for Moderna, and 52% for Pfizer-BioNTech.

Variations in temporal trends in non-traumatic dental condition related emergencies

OBJECTIVE

The objective of the study was to investigate temporal trends in non-traumatic dental condition (NTDC) related emergency visits at Emergency Department (ED), urgent care (UC), and at a Federally Qualified Health Center (FQHC) that providing dental services to a mid-sized rural community.

METHODS

Temporal trends over a 9-year period (2008-2016) in NTDC rates at ED, UC, FQHC and in a region around the FQHC were determined. Statistically significant changes (α = 0.05) in the proportion of NTDC visits between FQHC and UC across each of the time points were investigated.

RESULTS

Proportion of NTDC ED visits was relatively stable over the study period; whereas those at FQHC exceeded those at UC site beginning 2012 and were significantly (α = 0.05) higher than that of UC subsequently (2015-2016).

CONCLUSIONS

NTDCs are preventable dental conditions and the care provided in treating NTDCs in emergency settings is palliative and does not address the underlying conditions resulting in poor outcomes. The results presented elucidate the critical role of FQHCs in significantly reducing NTDC visits. These might be precursors to a potential shift in NTDC care seeking behavior and expected to favorably impact oral health outcomes.

Spatio-Temporal Dynamics of Tick-Borne Diseases in North-Central Wisconsin from 2000-2016

Lyme disease is a well-recognized public health problem in the USA, however, other tick-borne diseases also have major public health impacts. Yet, limited research has evaluated changes in the spatial and temporal patterns of non-Lyme tick-borne diseases within endemic regions. Using laboratory data from a large healthcare system in north-central Wisconsin from 2000-2016, we applied a Kulldorf's scan statistic to analyze spatial, temporal and seasonal clusters of laboratory-positive cases of human granulocytic anaplasmosis (HGA), babesiosis, and ehrlichiosis at the county level. Older males were identified as the subpopulation at greatest risk for non-Lyme tick-borne diseases and we observed a statistically significant spatial and temporal clustering of cases (p < 0.05). HGA risk shifted from west to east over time (2000-2016) with a relative risk (RR) ranging from 3.30 to 11.85, whereas babesiosis risk shifted from south to north and west over time (2004-2016) with an RR ranging from 4.33 to 4.81. Our study highlights the occurrence of non-Lyme tick-borne diseases, and identifies at-risk subpopulations and shifting spatial and temporal heterogeneities in disease risk. Our findings can be used by healthcare providers and public health practitioners to increase public awareness and improve case detection.

Earliest infections predict the age distribution of seasonal influenza A cases

Seasonal variation in the age distribution of influenza A cases suggests that factors other than age shape susceptibility to medically attended infection. We ask whether these differences can be partly explained by protection conferred by childhood influenza infection, which has lasting impacts on immune responses to influenza and protection against new influenza A subtypes (phenomena known as original antigenic sin and immune imprinting). Fitting a statistical model to data from studies of influenza vaccine effectiveness (VE), we find that primary infection appears to reduce the risk of medically attended infection with that subtype throughout life. This effect is stronger for H1N1 compared to H3N2. Additionally, we find evidence that VE varies with both age and birth year, suggesting that VE is sensitive to early exposures. Our findings may improve estimates of age-specific risk and VE in similarly vaccinated populations and thus improve forecasting and vaccination strategies to combat seasonal influenza.

Hospital Discharge Data Underascertain Enteric Bacterial Infections Among Children

Many enteric pathogens disproportionately infect children. Hospital discharge data can provide information on severe infections, including cost. However, the diagnosis must be recorded on the discharge record and coded accurately. We estimated the rate of underascertainment in hospital discharge data among children with culture-confirmed Campylobacter, Salmonella, and Escherichia coli O157 infections using linked laboratory and hospital discharge data from an integrated health care organization. We reviewed the International Classification of Diseases, 9th and 10th Revisions, Clinical Modification (ICD-9/10-CM) diagnosis codes on each patient's discharge record. We determined the percentage of patients who had a pathogen-specific diagnosis code (for Campylobacter, Salmonella, or E. coli O157) or nonspecific gastroenteritis code. We included the first admission or positive test and calculated the number of days between specimen submission (outpatient ≤7 days before admission or inpatient) and hospital discharge. Of 65 hospitalized children with culture-confirmed Campylobacter (n = 30), Salmonella (n = 24), or E. coli O157 (n = 11) infections, 55% had that pathogen-specific diagnosis code listed on the discharge record (79% Salmonella, 54% E. coli O157, 37% Campylobacter). The discharge records of the 35 children with a specimen submitted for culture ≥3 days before discharge were 16 times more likely to have a pathogen-specific diagnosis than the records of the 30 children with a specimen submitted <3 days before discharge (83% vs. 23%; odds ratio 15.9, 95% confidence interval: 4.7-53.8). Overall, 34% of records of children with culture-confirmed infection had ≥1 nonspecific gastroenteritis code (Campylobacter 43%, Salmonella 29%, E. coli O157 18%), including 59% of those for children without a pathogen-specific diagnosis (Campylobacter 63%; Salmonella 60%; E. coli O157 40%). This study showed that hospital discharge data under-ascertain enteric illnesses in children even when the infections are culture confirmed, especially for infections that usually have a short length of stay.

Serious outcomes of medically attended, laboratory-confirmed influenza illness among school-aged children with and without asthma, 2007-2018

Background

Asthma was associated with influenza hospitalizations in children during the 2009 pandemic, but it is unclear if asthma is associated with serious illness during seasonal epidemics. Little is known regarding the effect of vaccination on influenza severity in children with asthma.

Methods

Children aged 5‐17 years in a community cohort presenting with acute respiratory illness were prospectively enrolled and tested for influenza from 2007‐08 through 2017‐18 (excluding the 2009‐10 pandemic season). Data from the electronic health record were extracted to determine asthma status and serious outcomes associated with influenza infection. A serious outcome was defined as hospitalization, emergency department visit, and/or pneumonia diagnosis within 30 days of symptom onset. Multivariable logistic regression models were used to assess asthma status and effect of vaccination on odds of a serious outcome.

Results

One thousand seven hundred and sixty four medically‐attended influenza infections among school‐aged children were included. Asthma was confirmed in 287 (16%) children. A serious influenza‐associated outcome occurred in 104 (6%) children. The odds of a serious outcome did not differ between those with confirmed asthma and those without asthma [adjusted odds ratio (aOR): 1.35, 95% confidence interval (CI): (0.77‐2.35), P = .3]. The effect of vaccination on serious outcomes was not modified by asthma status [aOR for children without asthma: 0.55 (95% CI: 0.28‐1.07), children with asthma: 1.39 (95% CI: 0.53‐3.69); interaction P‐value = .12].

Conclusions

Asthma was not a risk factor for serious illness among children with influenza. Additional studies are needed to better understand the role of influenza vaccination in preventing serious outcomes among children with asthma.

Utility of Laboratory Test Result Monitoring in Patients Taking Oral Terbinafine or Griseofulvin for Dermatophyte Infections

Importance

Terbinafine hydrochloride and griseofulvin are effective oral treatments for dermatophyte infections but have been associated with hepatic and hematologic abnormalities. The prevalence of alanine aminotransferase elevations, aspartate aminotransferase elevations, anemia, lymphopenia, and neutropenia among adults and children taking terbinafine and griseofulvin is unclear.

Objective

To measure the rate of laboratory test result abnormalities in healthy adults and children taking terbinafine or griseofulvin for dermatophyte infections.

Design, Setting, and Participants

This retrospective study assessed adults and children taking terbinafine or griseofulvin for dermatophyte infections from January 1, 2006, to December 31, 2016. Data were collected from one Midwest health care system. Exclusion criteria were preceding diagnosis of hepatic or hematologic condition and preceding or concurrent use of oral ketoconazole, amphotericin, or itraconazole.

Main Outcomes and Measures

The rates of elevated alanine aminotransferase measurements, elevated aspartate aminotransferase measurements, anemia, lymphopenia, and neutropenia in adults and children taking terbinafine, griseofulvin microsize, or griseofulvin ultramicrosize were calculated. Secondary measures included rates of baseline abnormalities, frequency of laboratory test results that required additional testing or discontinued use of medication, and laboratory test result monitoring practices.

Results

This study included laboratory data from 4985 patients (mean [SD] age, 42.8 [20.3] years; 2288 [45.9%] female) receiving 4309 courses of terbinafine, 634 courses of griseofulvin microsize, and 159 courses of griseofulvin ultramicrosize. We identified a low rate of laboratory test result abnormalities in patients taking terbinafine or griseofulvin. When laboratory test result abnormalities occurred, most were low grade (212 [93.4%] grade 1) and did not require subsequent laboratory test result evaluation or discontinued use of medication (15 051 [99.9%]). Elevations in alanine aminotransferase measurements were detected infrequently and were comparable to baseline detection rates (61 [3.5%] vs 95 [3.6%] for terbinafine, 2 [2.1%] vs 3 [3.7%] for griseofulvin microsize, and 0 vs 2 [5.0%] for griseofulvin ultramicrosize). Rates of elevated aspartate aminotransferase measurements, anemia, lymphopenia, and neutropenia were also infrequent and comparable to baseline rates.

Conclusions and Relevance

In this study. the rates of alanine aminotransferase elevations, aspartate aminotransferase elevations, anemia, lymphopenia, and neutropenia in adults and children taking terbinafine or griseofulvin were low and equivalent to the baseline rates of abnormalities in this population. Routine interval laboratory test result monitoring appears to be unnecessary in adults and children without underlying hepatic or hematologic conditions taking terbinafine or griseofulvin for dermatophyte infections. Abandoning frequent laboratory monitoring can decrease unnecessary health care spending, decrease patient psychological angst associated with blood draws, and allow for expanded use of these effective oral medications.

Respiratory health, allergies, and the farm environment: design, methods and enrollment in the observational Wisconsin Infant Study Cohort (WISC): a research proposal

Epidemiologic and cross-sectional studies suggest that early life farming and animal exposures are associated with major health benefits, influencing immune development and modifying the subsequent risk of allergic diseases, including asthma. The Wisconsin Infant Study Cohort (WISC) study was established in central Wisconsin to test the hypothesis that early life animal farm exposures are associated with distinct innate immune cell maturation trajectories, decreased allergen sensitization and reduced respiratory viral illness burden during the first 2 years of life. Beginning in 2013, a total of 240 families have been enrolled, 16,522 biospecimens have been collected, and 4098 questionnaires have been administered and entered into a secure database. Study endpoints include nasal respiratory virus identification and respiratory illness burden score, allergic sensitization, expression of allergic disease, and anti-viral immune response maturation and profiles. The WISC study prospective design, broad biospecimen collections, and unique US rural community will provide insights into the role of environmental exposures on early life immune maturation profiles associated with protection from allergic sensitization and significant respiratory viral disease burden. The WISC study findings will ultimately inform development of new strategies to promote resistance to severe respiratory viral illnesses and design primary prevention approaches for allergic diseases for all infants.

Assessing Potential Confounding and Misclassification Bias When Studying the Safety of the Childhood Immunization Schedule

OBJECTIVES

Some parents are concerned the childhood immunization schedule could increase risk for allergic disorders, including asthma. To inform future safety studies of this speculated association, a parent survey was conducted to examine the risk of misclassification of vaccination status in electronic health record data, and to assess the potential for confounding if asthma risk factors varied by vaccination status.

METHODS

A survey was conducted among parents of children 19 to 35 months old at 6 medical organizations within the Vaccine Safety Datalink. Parents of children in 4 vaccination groups were surveyed: 1) no vaccines by 12 months of age and a diagnosis of parental vaccine refusal; 2) consistent vaccine limiting (≤2 vaccines per visit); 3) not consistently vaccine limiting but otherwise undervaccinated with a vaccine refusal diagnosis; and 4) fully vaccinated with no delays and no vaccine refusal. Parents were surveyed about their child's vaccination status and whether asthma risk factors existed.

RESULTS

Among a survey sample of 2043 parents, 1209 responded (59.2%). For receiving no vaccines, the observed agreement between parent report and electronic health record data was 94.0% (κ = 0.79); for receiving all vaccines with no delays, the observed agreement was 87.3% (κ = 0.73). Although most asthma risk factors (allergic rhinitis, eczema, food allergies, family asthma history) reported by parents did not differ significantly between children in the vaccination groups studied, several factors (aeroallergen sensitivity, breastfeeding) differed significantly between groups.

CONCLUSIONS

Measurement and control of disease risk factors should be carefully considered in observational studies of the safety of the immunization schedule.

Hospitalisations due to bacterial gastroenteritis: A comparison of surveillance and hospital discharge data

Studies estimating the human health impact of the foodborne disease often include estimates of the number of gastroenteritis hospitalisations. The aims of this study were to examine the degree to which hospital discharge data underreport hospitalisations due to bacterial gastroenteritis and to estimate the frequency of stool sample submission among patients presenting with gastroenteritis. Using linked laboratory and hospital discharge data from a healthcare organisation and its affiliated hospital, we examined the International Classification of Disease (ICD-9-CM) diagnosis codes assigned to hospitalised adults with culture-confirmed Campylobacter, Salmonella, or Escherichia coli O157 infections and determined the frequency of stool sample submission. Among 138 hospitalised patients with culture-confirmed infections, 43% of Campylobacter patients, 56% of Salmonella patients and 35% of E. coli O157 patients had that pathogen-specific code listed on the discharge record. Among patients without their infection listed as a diagnosis, 65% were assigned a nonspecific gastroenteritis code. Submitting a specimen for culture ⩾3 days before discharge was significantly associated with having the pathogen-specific diagnosis listed. Of 6181 patients assigned a nonspecific gastroenteritis code, 69% had submitted a stool sample for bacterial culture. This study can be used to understand differences and adjust for the underreporting and underdiagnosed of Campylobacter, Salmonella and E. coli O157 in hospital discharge and surveillance data, respectively.

Burden of medically attended influenza infection and cases averted by vaccination - United States, 2013/14 through 2015/16 influenza seasons

BACKGROUND

In addition to preventing hospitalizations and deaths due to influenza, influenza vaccination programs can reduce the burden of outpatient visits for influenza. We estimated the incidence of medically-attended influenza at three geographically diverse sites in the United States, and the cases averted by vaccination, for the 2013/14 through 2015/16 influenza seasons.

METHODS

We defined surveillance populations at three sites from the United States Influenza Vaccine Effectiveness Network. Among these populations, we identified outpatient visits laboratory-confirmed influenza via active surveillance, and identified all outpatient visits for acute respiratory illness from healthcare databases. We extrapolated the total number of outpatient visits for influenza from the proportion of surveillance visits with a positive influenza test. We combined estimates of incidence, vaccine coverage, and vaccine effectiveness to estimate outpatient visits averted by vaccination.

RESULTS

Across the three sites and seasons, incidence of medically attended influenza ranged from 14 to 54 per 1000 population. Incidence was highest in children aged 6 months to 9 years (33 to 70 per 1000) and lowest in adults aged 18-49 years (21 to 27 per 1000). Cases averted ranged from 9 per 1000 vaccinees (Washington, 2014/15) to 28 per 1000 (Wisconsin, 2013/14).

DISCUSSION

Seasonal influenza epidemics cause a considerable burden of outpatient medical visits. The United States influenza vaccination program has caused meaningful reductions in outpatient visits for influenza, even in years when the vaccine is not well-matched to the dominant circulating influenza strain.

Incidence of Primary Biliary Cholangitis in a Rural Midwestern Population

BACKGROUND

Primary biliary cholangitis (PBC) is a rare disease with incidence that varies with time and geography. Only two studies have assessed PBC incidence in the United States, with the most recent appearing over a decade ago. The objective of the present study was to assess PBC incidence in the United States in a more recent era.

METHODS

The incidence of PBC was assessed in a population-based cohort in rural, Midwestern Wisconsin over two decades spanning from June 1992 through June 2011. Cases were initially identified in the electronic medical record and then manually verified for inclusion according to the American Association for the Study of Liver Disease criteria for PBC. Additional data were abstracted for verified cases.

RESULTS

A total of 79 cases of PBC were identified over the 20-year period for an overall age- and sex-standardized incidence of 4.9 cases per 100,000 person-years. Incidence was higher in females, but changes over time were not significant. After a mean 7.3 years follow-up, all-cause mortality of those with PBC was 29%, and estimated 10-year survival was 76%.

CONCLUSIONS

The overall incidence of PBC in a Midwestern population of the United States has remained relatively stable over the last two decades. Patients have better prognosis, and the survival of PBC cases has improved.

Adverse Childhood Experiences and Health in Adulthood in a Rural Population-Based Sample

BACKGROUND

Adverse childhood experiences (ACEs), including emotional abuse, substance abuse in the household, separation or divorce, physical abuse, violence between adults, mental illness in the household, sexual abuse, or incarceration of a household member, have the potential to profoundly impact health and well-being in adulthood. To assess whether previously reported relationships between ACEs and health outcomes withstand validation, we conducted a community-based ACE study with the unique capacity to link self-reported ACEs and other survey results to validated health data in an electronic medical record (EMR).

METHODS

Information regarding ACEs and health outcomes was captured from 2013-2014 via a telephone survey of residents of the predominantly rural northern and central regions of Wisconsin and electronic abstraction of EMR data. ACE score was calculated by counting each exposure as one point. We examined the relationship between ACE score, type, and self-reported and validated health outcomes.

RESULTS

A total of 800 participants completed the telephone survey. Overall, 62% reported at least one ACE and 15% reported experiencing four or more. All self-reported measures of poor health were associated with increased ACE score. EMR data were positively correlated with ACE score for increased body mass index and diagnoses of depression, anxiety, and asthma. In contrast, diagnoses of hypertension, hypercholesterolemia, myocardial infarction, and skin and other cancers were inversely related to ACE score. Emotional abuse was the most common ACE reported followed by substance abuse in the household. ACEs tended to cluster so that people who reported at least one ACE were likely to have experienced multiple ACEs. There was no clear correlation between abuse type (e.g., direct abuse vs. household dysfunction) and health outcomes.

CONCLUSIONS

In the first community-based study to link self-reported ACEs to comprehensive health measures documented in the medical record, we observed previously reported associations between childhood adversity and poor outcomes in adulthood, but also noted an inverse relationship between ACE score and certain medical diagnoses. Potential explanations for this finding warrant further investigation.

Incidence of Medically Attended Respiratory Syncytial Virus and Influenza Illnesses in Children 6-59 Months Old During Four Seasons

RSV was the most common viral agent causing acute respiratory illness in children 6 to 59 months old during the influenza season. Children in the 6-23 month age range had a higher incidence of RSV compared to those aged 24-59 months.

Background. Respiratory syncytial virus (RSV) and influenza are significant causes of seasonal respiratory illness in children. The incidence of influenza and RSV hospitalization is well documented, but the incidence of medically attended, laboratory-confirmed illness has not been assessed in a well defined community cohort.

Methods. Children aged 6–59 months with medically attended acute respiratory illness were prospectively enrolled during the 2006–2007 through 2009–2010 influenza seasons in a Wisconsin community cohort. Nasal swabs were tested for RSV and influenza by multiplex reverse-transcription polymerase chain reaction. The population incidence of medically attended RSV and influenza was estimated separately and standardized to weeks 40 through 18 of each season.

Results. The cohort included 2800–3073 children each season. There were 2384 children enrolled with acute respiratory illness; 627 (26%) were positive for RSV and 314 (13%) for influenza. The mean age was 28 months (standard deviation [SD] = 15) for RSV-positive and 38 months (SD = 16) for influenza-positive children. Seasonal incidence (cases per 10 000) was 1718 (95% confidence interval [CI], 1602–1843) for RSV and 768 (95% CI, 696–848) for influenza. Respiratory syncytial virus incidence was highest among children 6–11 (2927) and 12–23 months old (2377). Influenza incidence was highest (850) in children 24–59 months old. The incidence of RSV was higher than influenza across all seasons and age groups.

Conclusions. The incidence of medically attended RSV was highest in children 6–23 months old, and it was consistently higher than influenza. The burden of RSV remains high throughout the first 2 years of life.

Epidemiologic trends in medically-attended tree stand fall injuries among Wisconsin deer hunters

BACKGROUND

Tree stand falls are the most common injury to hunters in the USA, but there is limited research on the topic. This study examined the 5-year trends in incident tree stand fall injuries in rural north-central Wisconsin and described patient demographics and injury features.

METHODS

A retrospective analysis was conducted on five prior hunting seasons, 2009-2013. Cases were ascertained from electronic health records via natural language processing that identified patients from the Marshfield Epidemiologic Study Area who received medical attention for a tree stand fall. Annual incidence rates were calculated using the number of hunting license holders in the target population, per administrative data from the Wisconsin Department of Natural Resources.

RESULTS

There were 16,556-16,902 deer hunters in any given year, with 39 (92% male) confirmed medically-attended tree stand fall injuries in 2009-2013. Injuries mainly occurred in the lower extremities (n=23), and included two fatalities and one paralysis case. The risk of tree stand fall injuries went from 6.0 (95% CI: 3.2, 11.1) per 10,000 hunters in 2009 to 3.6 (95% CI: 1.6, 7.9) per 10,000 hunters in 2013, which was not a significant change over 5 years (p=0.79). Most falls occurred among archery hunters, in the evening and when descending from a tree stand. Cases were demographically similar to the general population of Wisconsin deer hunters.

CONCLUSIONS

The current seasonal incidence rate of tree stand fall injuries is relatively low in rural Wisconsin, but with limited signs of improvement. Continued efforts are needed to promote the long-term safety of the hunting public.