Timothy K. Thomas

Duration of protection against hepatitis A for the current two-dose vaccine compared to a three-dose vaccine schedule in children

BACKGROUND Hepatitis A is mostly a self-limiting disease but causes substantial economic burden. Consequently, United States Advisory Committee for Immunization Practices recommends inactivated hepatitis A vaccination for all children beginning at age 1 year and for high risk adults. The hepatitis A vaccine is highly effective but the duration of protection is unknown. METHODS We examined the proportion of children with protective hepatitis A antibody levels (anti-HAV ≥20 mIU/mL) as well as the geometric mean concentration (GMC) of anti-HAV in a cross sectional convenience sample of individuals aged 12-24 years, who had been vaccinated with a two-dose schedule in childhood, with the initial dose at least 5 years ago. We compared a subset of data from persons vaccinated with two-doses (720 EL.U.) at age 3-6 years with a demographically similar prospective cohort that received a three-dose (360 EL.U.) schedule and have been followed for 17 years. RESULTS No significant differences were observed when comparing GMC between the two cohorts at 10 (P=0.467), 12 (P=0.496), and 14 (P=0.175) years post-immunization. For the three-dose cohort, protective antibody levels remain for 17 years and have leveled-off over the past 7 years. CONCLUSION The two- and three-dose schedules provide similar protection >14 years after vaccination, indicating a booster dose is not needed at this time. Plateauing anti-HAV GMC levels suggest protective antibody levels may persist long-term.

Impact of providing in-home water service on the rates of infectious diseases: results from four communities in Western Alaska

Approximately 20% of rural Alaskan homes lack in-home piped water; residents haul water to their homes. The limited quantity of water impacts the ability to meet basic hygiene needs. We assessed rates of infections impacted by water quality (waterborne, e.g. gastrointestinal infections) and quantity (water-washed, e.g. skin and respiratory infections) in communities transitioning to in-home piped water. Residents of four communities consented to a review of medical records 3 years before and after their community received piped water. We selected health encounters with ICD-9CM codes for respiratory, skin and gastrointestinal infections. We calculated annual illness episodes for each infection category after adjusting for age. We obtained 5,477 person-years of observation from 1032 individuals. There were 9,840 illness episodes with at least one ICD-9CM code of interest; 8,155 (83%) respiratory, 1,666 (17%) skin, 241 (2%) gastrointestinal. Water use increased from an average 1.5 gallons/capita/day (g/c/d) to 25.7 g/c/d. There were significant (P-value < 0.05) declines in respiratory (16, 95% confidence interval (CI): 11-21%), skin (20, 95%CI: 10-30%), and gastrointestinal infections (38, 95%CI: 13-55%). We demonstrated significant declines in respiratory, skin and gastrointestinal infections among individuals who received in-home piped water. This study reinforces the importance of adequate quantities of water for health.

Cost-effectiveness of preventing dental caries and full mouth dental reconstructions among Alaska Native children in the Yukon–Kuskokwim delta region of Alaska

Objective We conducted a cost-effectiveness analysis of five specific dental interventions to help guide resource allocation. Methods We developed a spreadsheet-based tool, from the healthcare payer perspective, to evaluate the cost effectiveness of specific dental interventions that are currently used among Alaska Native children (6-60 months). Interventions included: water fluoridation, dental sealants, fluoride varnish, tooth brushing with fluoride toothpaste, and conducting initial dental exams on children <18 months of age. We calculated the cost-effectiveness ratio of implementing the proposed interventions to reduce the number of carious teeth and full mouth dental reconstructions (FMDRs) over 10 years. Results A total of 322 children received caries treatments completed by a dental provider in the dental chair, while 161 children received FMDRs completed by a dental surgeon in an operating room. The average cost of treating dental caries in the dental chair was

Washeteria closures, infectious disease and community health in rural Alaska: a review of clinical data in Kivalina, Alaska.

1,467 (~258,000 per year); while the cost of treating FMDRs was

Developing a Biomarker Feedback Intervention to Motivate Smoking Cessation During Pregnancy: Phase II MAW Study

9,349 (~1.5 million per year). All interventions were shown to prevent caries and FMDRs; however tooth brushing prevented the greatest number of caries at minimum and maximum effectiveness with 1,433 and 1,910, respectively. Tooth brushing also prevented the greatest number of FMDRs (159 and 211) at minimum and maximum effectiveness. Conclusions All of the dental interventions evaluated were shown to produce cost savings. However, the level of that cost saving is dependent on the intervention chosen.

Perceived risks and reasons to smoke cigarettes during pregnancy among Alaska native women

Background Kivalina is a northwest Alaska barrier island village of 400 people vulnerable to storm surges exacerbated recently by delayed winter sea and shore ice formation. The village has no in-home piped water or sewage; the “washeteria” is the only structure providing public showers, laundry facilities and flush toilets. In October 2004, a storm damaged the washeteria septic system resulting in prolonged facility closures. We assessed rates of gastrointestinal, respiratory and skin infections potentially impacted by prolonged washeteria closures. Methods We obtained washeteria closure dates from 2003 to July 2009 and defined >7 day closure as prolonged. We received de-identified data on all Kivalina clinic visits from 2003 to 2009 and selected visits with ICD-9 diagnosis codes for respiratory, skin, or gastrointestinal infection; subsequent same patient/same illness-category visits within 14 days were excluded. We compared annual visit rates, for all ages combined, before (2003–2004) and after (2005–2009) the “2004” storm. Results The washeteria had prolonged closures for 34 days (4.7%) in the 2 years 2003–2004 and 864 days (51.7%) between January 2005 and July 2009. Closures ranged from 8 to 248 days. Respiratory infection rates declined significantly from 1.32 visits/person/year in the 2003–2004 period to 0.99 visits/person/year in the 2005–2009 period. There was a significant increase in skin infection rates after 2004, peaking at 0.28 visits/person/year in 2007 and then declining significantly to 0.15 visits/person/year in 2009. Gastrointestinal infection rates remained stable and low throughout (average: 0.05 visits/person/year). No temporal association was observed between respiratory, gastrointestinal or skin infection rates and prolonged washeteria closures. Conclusion The Kivalina washeteria was closed frequently and for extended periods between 2005 and 2009. Initial closures possibly resulted in increased skin infection rates. No increase in respiratory or gastrointestinal infections was noted. Evaluation of community adaptations to closures and other factors (e.g. childhood pneumococcal vaccination) would expand understanding of these findings.

The search for an alternative to piped water and sewer systems in the Alaskan Arctic

Introduction The prevalence of smoking during pregnancy for Alaska Native (AN) women is more than triple that of non-Native Alaska women. In this qualitative study, we solicited input from AN women and others to determine how best to present findings from an earlier study demonstrating a strong correlation between biomarkers for maternal smoking (cotinine) and neonatal exposure to a tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) to motivate cessation. Methods We developed a brochure incorporating generalized biomarker information. Using in-depth individual interviews with pregnant and postpartum AN women and partners/family members, we explored applicability and acceptability of the information. Postpartum women, who had participated in the earlier correlation study, additionally received their individual biomarker results. We assessed whether being presented general or individual biomarker information would motivate cessation using content analysis. Results We conducted 39 interviews: 16 pregnant women, 12 postpartum women, and 11 partners/family members. Overall, participants agreed the biomarker information was new, but understandable as presented. Postpartum women shared that learning their personal results inspired them to want to quit or cut back smoking while pregnant women indicated the generalized correlation information was less helpful in motivating cessation. Conclusion Generalized information about fetal exposure to carcinogens may be more effective in motivating pregnant women to quit smoking when combined with individual cotinine testing. Implications Using feedback from this study, we refined and are currently evaluating an intervention incorporating generalized correlation information from Phase I and cotinine testing to determine its effectiveness in motivating smoking cessation among pregnant AN women.

Biomarker Feedback Intervention for Smoking Cessation among Alaska Native Pregnant Women: Randomized Pilot Study

ABSTRACT Objective: The purpose of this study was to explore perceptions of the risks of smoking and reasons Alaska Native women give for smoking during pregnancy. Design: A total of 118 women (54 smokers, 64 non-smokers) enrolled in a biomarker study and completed a baseline interview asking about their concerns regarding tobacco use while pregnant and reasons why pregnant women might smoke during pregnancy. Responses were collapsed into six categories of perceived risks of smoking and eight categories of reasons to smoke during pregnancy. Results: The majority of both pregnant non-smokers and smokers (72.6% and 60.4%) agreed that smoking during pregnancy could negatively impact the health of their baby. However, non-smokers were more likely than smokers (77.4% vs. 58.5%) to view smoking during pregnancy as a risk factor for the baby’s development (p = .029). Both non-smokers and smokers identified addiction as a reason for smoking during pregnancy (82.8% and 63%); however, non-smokers were more likely than smokers to state this was a reason for use (p = .015). Seventy-three percent of the entire sample reported a reason to smoke in pregnancy was to help manage negative affect. Conclusion: Results from this work may be helpful in advancing research by identifying targets for intervention specific to Alaska Native women receiving prenatal care in Anchorage, Alaska.

Disproportionately higher unintentional injury mortality among Alaska Native people, 2006-2015

Forty-two communities in rural Alaska are considered unserved or underserved with water and sewer infrastructure. Many challenges exist to provide centralized piped water and sewer infrastructure to the homes, and they are exacerbated by decreasing capital funding. Unserved communities in rural Alaska experience higher rates of disease, supporting the recommendation that sanitation infrastructure should be provided. Organizations are pursuing alternative solutions to conventional piped water and sewer in order to maximize water use and reuse for public health. This paper reviews initiatives led by the State of Alaska, the Alaska Native Tribal Health Consortium, and the Yukon Kuskokwim Health Corporation to identify and develop potential long-term solutions appropriate and acceptable to rural communities. Future developments will likely evolve based on the lessons learned from the initiatives. Recommendations include Alaska-specific research needs, increased end-user participation in the design process, and integrated monitoring, evaluation, and information dissemination in future efforts.

Urine 4-(methylnitrosamino)-1-(3) pyridyl-1-butanol and cotinine in Alaska native postpartum women and neonates comparing smokers and smokeless tobacco users.

OBJECTIVE There is some evidence for biomarker feedback when combined with cessation counseling for reducing smoking in pregnancy. This randomized controlled pilot study evaluated feasibility and potential efficacy of a social-cognitive theory (SCT)-based biomarker feedback intervention among pregnant Alaska Native (AN) smokers. METHODS Participants were randomly assigned to receive three study calls (10-20 min each): (1) biomarker feedback intervention (n = 30) including personalized cotinine results and feedback on their babys likely exposure to carcinogen metabolite NNAL, or (2) contact control usual care condition based on the 5As (n = 30). Assessments were conducted at baseline, post-treatment, and delivery. RESULTS High rates of treatment compliance, study retention, and treatment acceptability were observed in both groups. 7-day point prevalence smoking abstinence rates at delivery verified with urinary cotinine were the same in both study groups (20% intent-to-treat analysis, 26% per-protocol). SCT-based measures did not change differentially from baseline by study group. CONCLUSION This trial supports the feasibility and acceptability of providing biomarker feedback within the clinical care delivery system, but the intervention did not promote increased smoking cessation during pregnancy compared to usual care. PRACTICE IMPLICATIONS Efforts are needed to promote the usual care and to develop alternative biomarker feedback messaging for pregnant AN women.