Streptococcus pneumoniae serotype 3 population structure in the era of conjugate vaccines, 2001-2018.

Background. Despite use of highly effective conjugate vaccines, invasive pneumococcal disease (IPD) remains a leading cause of morbidity and mortality and disproportionately affects Indigenous populations. Although included in the 13-valent pneumococcal conjugate vaccine (PCV13), which was introduced in 2010, serotype 3 continues to cause disease among Indigenous communities in the Southwest USA. In the Navajo Nation, serotype 3 IPD incidence increased among adults (3.8/100 000 in 2001-2009 and 6.2/100 000 in 2011-2019); in children the disease persisted although the rates dropped from 5.8/100 000 to 2.3/100 000.Methods. We analysed the genomic epidemiology of serotype 3 isolates collected from 129 adults and 63 children with pneumococcal carriage (n=61) or IPD (n=131) from 2001 to 2018 of the Navajo Nation. Using whole-genome sequencing data, we determined clade membership and assessed changes in serotype 3 population structure over time.Results. The serotype 3 population structure was characterized by three dominant subpopulations: clade II (n=90, 46.9 %) and clade Iα (n=59, 30.7 %), which fall into Clonal Complex (CC) 180, and a non-CC180 clade (n=43, 22.4 %). The proportion of clade II-associated IPD cases increased significantly from 2001 to 2010 to 2011-2018 among adults (23.1-71.8 %; P<0.001) but not in children (27.3-33.3 %; P=0.84). Over the same period, the proportion of clade II-associated carriage increased; this was statistically significant among children (23.3-52.6 %; P=0.04) but not adults (0-50.0 %, P=0.08).Conclusions. In this setting with persistent serotype 3 IPD and carriage, clade II has increased since 2010. Genomic changes may be contributing to the observed trends in serotype 3 carriage and disease over time.

The Navajo Nation Healthy Diné Nation Act: Community Support of a 2% Tax on Unhealthy Foods.

CONTEXT: The Healthy Diné Nation Act (HDNA) of 2014 included a 2% tax on foods of little-to-no-nutritious value ("junk foods") on the Navajo Nation. The law was the first ever in the United States and any Indigenous nation worldwide with a population at a high risk for common nutrition-related conditions. To date, research on community support for food tax legislation among Indigenous nations is entirely lacking. OBJECTIVE: To assess the extent of support for the HDNA and factors associated with support including sociodemographic variables, knowledge of the HDNA, nutrition intake, and pricing preferences. DESIGN: Cross-sectional survey. SETTING: The Navajo Nation. PARTICIPANTS: A total of 234 Navajo Nation community members across 21 communities. OUTCOME MEASURES: The percentage of participants who were supportive of the HDNA. RESULTS: Participants were 97% Navajo, on average middle-aged, 67% reported an income below $25 000 annually, and 69.7% were female. Half of the respondents said they "support" (37.4%) or "strongly support" (13.0%) the tax, while another 35% of people said they were neutral or somewhat supportive; 15% did not support the tax. Participants with higher income ( P = .025) and education ( P = .026) and understanding of the legislation ( P < .001 for "very well" vs "not at all") had increased odds of greater support, as did people who believed that the HDNA would make Navajo people healthier (vs not, P < .001). Age, gender, language, and reported nutrition intake (healthy or unhealthy) were not associated with HDNA support, but participants willing to pay 5% or 12%-15% higher prices for fast food and soda had increased odds of greater support ( P values range from .023 to <.001). CONCLUSIONS: The majority of Navajo community members surveyed were moderately supportive of the Navajo Nation tax on unhealthy foods. Higher income and education and understanding of the law were associated with greater support, but nutrition intake was not.

Practicing Tribal Sovereignty Through a Tribal Health Policy: Implementation of the Healthy Diné Nation Act on the Navajo Nation.

INTRODUCTION: The Navajo Nation is a large sovereign tribal nation. After several years of grassroots efforts and overcoming an initial presidential veto, the Navajo Nation passed the Healthy Diné Nation Act (HDNA) in 2014 to promote healthy behaviors in Navajo communities. This was the first such policy in the US and in any sovereign tribal nation worldwide. PURPOSE AND OBJECTIVES: The objective of this study was to describe the process, implementation, and evaluation of the HDNA passage and its 2020 reauthorization and the potential for using existing and tribal-specific data to inform tribal policy making. INTERVENTION APPROACH: The HDNA included a 2% tax on unhealthy foods sold on the Navajo Nation and waived a 6% sales tax on healthy foods. HDNA-generated funds were allocated to 110 local communities for wellness projects. No funds were allocated for enforcement or compliance. EVALUATION METHODS: We assessed HDNA tax revenue and tax-funded wellness projects in 110 chapters over time, by region and community size. The food store environment was assessed for fidelity of HDNA implementation, price changes since pretax levels, and shopper behaviors. HDNA revenue was cross-matched with baseline nutrition behaviors and health status through a Navajo-specific Behavioral Risk Factor Surveillance System survey. RESULTS: HDNA revenue decreased modestly annually, and 99% of revenue was disbursed to local chapters, mostly for the built recreational environment, education, equipment, and social events. Stores implemented the 2% tax accurately, and the food store environment improved modestly. Regions with high tax revenue also had high rates of diabetes, but not other chronic conditions. The HDNA was reauthorized in 2020. IMPLICATIONS FOR PUBLIC HEALTH: Sovereign tribal nations can drive their own health policy. Program evaluation can use existing data sources, tailored data collection efforts, and tribal-specific surveys to gain insight into feasibility, implementation, and impact.

Navajo Nation Stores Show Resilience During COVID-19 Pandemic.

On April 8, 2020, the Navajo Nation issued an administrative order limiting business operations. Facing high coronavirus disease 2019 (COVID-19) rates and limited food infrastructure, a survey was conducted among Navajo Nation store managers to assess: (1) COVID-19 adaptations; (2) challenges; (3) changes in customer volume and purchasing; and (4) suggestions for additional support. Purposive sampling identified 29 stores in Navajo communities. Representatives from 20 stores (19 store managers/owners, 1 other; 7 grocery, and 13 convenience/other stores) were interviewed by phone or in-person to reach saturation (new information threshold < 5%). Responses were coded using frequencies and inductive thematic analysis. All 20 stores implemented COVID-19 guidelines (Centers for Disease Control and Prevention [CDC]/Navajo Nation) and most received orientation/support from local chapters, community organizations, or health centers. Stores implemented staff policies (50%, handwashing, vaccinations, protective personal equipment (PPE), sick leave, temperature checks), environmental changes (50%, hand sanitizer, checkout dividers), customer protocols (40%, limit customers, mask requirements, closed restrooms), and deep cleaning (40%). Most stores (65%) reported challenges including stress/anxiety, changing guidelines, supply chain and customer compliance; 30% reported infection or loss of staff. Weekday customer volume was slightly higher vs. pre-COVID, but weekend lower. Stores reported consistent or more healthy food purchases (50%), more nonfood essentials (20%), or shelf-stable foods (10%). Desired support included further orientation (30%), leadership support (20%), overtime/time to learn guidelines (20%), and signage/handouts (15%). Despite a high COVID-19 burden and limited food store infrastructure, Navajo Nation stores adapted by implementing staff, environmental and customer policies. Local support, staffing, and small store offerings were key factors in healthy food access.

Implementation of Indigenous Food Tax Policies in Stores on Navajo Nation.

In 2014, the Navajo Nation Healthy Diné Nation Act (HDNA) was enacted and permanently approved in 2020; HDNA places a 2% surtax on unhealthy foods and beverages, while other 2014 legislation exempted healthy food items from the 6% regular sales tax. Little is known about Navajo Nation store manager/owner perspectives toward the HDNA and how best to support stores to implement the legislation. Purposive sampling was used to ensure a balanced sample of correct HDNA implementers, incorrect HDNA implementers, and stores which made healthy store changes over the past 6 years. Three community-based interviewers collected surveys by phone or in-person. Frequency of closed-ended questions was quantified, and open-ended responses were coded using thematic analysis. Of 29 identified sample stores, 20 were interviewed to reach saturation. Eleven of 20 stores made changes improving their healthy food environments. Barriers included lack of equipment (6/20) and low consumer demand (5/20). Facilitators included consumer awareness and increased produce supply options (5/20). Sixteen of 20 stores supported HDNA continuation. Facilitators to HDNA implementation included orientation and informational materials (6/20) and promotion of tax-free items (5/20). Barriers included confusion about the tax (6/20) and tax exemption (5/20). Suggestions for support included printed materials (6/20) and store training (5/20). HDNA benefits included greater awareness of healthy choices among staff (7/20) and customer-community members (2/20). Most managers and owners expressed receiving support for healthy store changes and HDNA, but also identified a need for added resources and support. Findings inform legislative action to promote timely and appropriate uptake of HDNA, and support equitable, healthy food systems.

Shopper Purchasing Trends at Small Stores on the Navajo Nation since the Passage of the Healthy Diné Nation Act Tax: A Multi-Year Cross-sectional Survey.

Background: In 2014, the Navajo Nation passed the Healthy Diné Nation Act (HDNA), which applies an additional 2% tax on unhealthy foods and beverages and a waiver of Navajo sales tax on healthy foods and beverages. However, the HDNA's impact on purchasing behavior has not been explored. Objectives: We assessed beverage and produce purchasing trends among shoppers at small Navajo stores between 2017 and 2019, shopper characteristics associated with buying water, and whether HDNA awareness was associated with purchasing behaviors. Methods: A total of 332 shoppers at 34 stores in 2017 and 274 shoppers at 44 stores in 2019 were surveyed to assess HDNA awareness and same-day purchasing of water, sugar-sweetened beverages (SSBs), fruits, and vegetables. Hypotheses were tested using chi-square analyses and multivariate analysis. Results: Water purchasing among respondents increased significantly from 2017 to 2019 (24.4% to 32.8%; P = 0.03). Shoppers in 2019 were 1.5 times more likely to purchase water compared with 2017 (adjusted P = 0.01). There was a trend toward reduced SSB purchasing (85.8% in 2017, 80.3% in 2019, P = 0.068), while produce purchasing remained unchanged over time, at approximately 17%. Shoppers were more likely to buy water if they relied on that store for the majority of their groceries (P = 0.006) and if they did not have their own transportation to get to the store (P = 0.004). Most shoppers (56.6%) were aware of the HDNA; of these, 35.6% attributed healthier habits to the HDNA, most commonly buying more healthy drinks (49.2%), fewer unhealthy drinks (37.7%), more healthy snacks (31.1%), and fewer unhealthy snacks (26.2%). Conclusions: Shopper habits at small stores located on the Navajo Nation have shifted towards healthier purchasing from 2017 to 2019. Shoppers who were aware of the HDNA reported purchasing more healthy and fewer unhealthy food and drinks as a result of this legislation.

Hantavirus Disease and COVID-19.

OBJECTIVES: Navajo Nation is disproportionately affected by hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease that can quickly progress to respiratory failure and cardiogenic shock. The initial signs and symptoms of HCPS are indistinguishable from coronavirus disease 2019 (COVID-19). However, this distinction is critical, as the disease course differs greatly, with most patients with COVID-19 experiencing mild to moderate illness. We set out to determine if the evaluation of peripheral blood smears for five hematopathologic criteria previously identified as hallmarks of hantavirus infection, or "the hantavirus 5-point screen," could distinguish between COVID-19 and HCPS. METHODS: The hantavirus 5-point screen was performed on peripheral blood smears from 139 patients positive for COVID-19 seeking treatment from Tséhootsooí Medical Center and two Emory University hospitals. RESULTS: Of these 139 individuals, 136 (98%) received a score of 3/5 or below, indicating low suspicion for HCPS. While thrombocytopenia, one of the key signs of HCPS, was seen in the patients with COVID-19, it was generally mild and remained stable on repeat specimens collected 12 to 24 hours later. CONCLUSIONS: Given these findings, the 5-point screen remains a useful rapid screening tool for potential HCPS cases and may be useful to distinguish early HCPS from COVID-19 in HCPS endemic regions.

Successful Implementation of a Rapid Screening Tool for Hantavirus Cardiopulmonary Syndrome: 5 Years of Experience From a Community Hospital in an Endemic Region.

OBJECTIVES: Hantavirus is endemic in the Four Corners region of Arizona, Colorado, New Mexico, and Utah, and hantavirus cardiopulmonary syndrome (HCPS) disproportionately affects the Navajo Nation. We describe the application of a rapid screening tool for identification of HCPS. METHODS: A rapid screening tool for HCPS was implemented at Tséhootsooí Medical Center (TMC) in collaboration with academic partners. RESULTS: Since its implementation in 2016, 20 TMC staff members have been trained to perform this test, and 189 screens for HCPS have been reported. Although hantavirus infection is rare even in high-risk areas, use of this tool resulted in the identification of 4 acute cases of hantavirus infection. CONCLUSIONS: The results demonstrate the successful implementation of a 5-point screening tool for hantavirus infection in an endemic setting by a laboratory in a small community hospital.

The Navajo Nation Healthy Diné Nation Act: A Description of Community Wellness Projects Funded by a 2% Tax on Minimal-to-No-Nutritious-Value Foods.

CONTEXT: To promote the health of the Navajo people, the Navajo Nation passed the Healthy Diné Nation Act (HDNA) in 2014. The HDNA included a 2% tax on "minimal-to-no-nutritional-value" foods and waived 5% sales tax on healthy foods, the first such policy in the United States and any sovereign Tribal nation. Uniquely aligned with Tribal government structures, revenue was directly allocated to 110 small local government entities (Chapters) for self-determined wellness projects. OBJECTIVE: To characterize HDNA-funded wellness projects, test for variation in project type, and funding amount over time by region and community size. DESIGN: Longitudinal study assessing funded wellness projects from tax inception through 2019. SETTING: The Navajo Nation. PARTICIPANTS: One hundred ten Navajo Nation Chapters receiving funding for self-determined wellness projects. OUTCOME MEASURES: The categories and specific types of wellness projects and funding over 4 years by region and community size. RESULTS: Of revenue collected in 2015-2018, more than 99.1% was disbursed through 2019 ($4.6 million, $13 385 annually per community) across 1315 wellness projects (12 per community). The built recreational environment category received 38.6% of funds, equipment/supplies 16.5%, instruction 15.7%, food and water initiatives 14.0%, and social events 10.2%. Most common specific projects were walking trails ($648 470), exercise equipment ($585 675), food for events ($288 879), playgrounds ($287 471), and greenhouses ($275 554). Only the proportion allocated to instruction changed significantly over time (increased 2% annually, P = .02). Smaller communities (population <1000) allocated significantly higher proportions to traditional, agricultural, and intergenerational projects and less to the built environment. CONCLUSIONS: Through 2019, more than 99% of HDNA revenue was successfully disbursed to 110 rural, Tribal communities. Communities chose projects related to promoting the built recreational environment, agriculture, and fitness/nutrition education, with smaller communities emphasizing cultural and intergenerational projects. These findings can inform other indigenous nations considering similar policies and funding distributions.

Changes in food pricing and availability on the Navajo Nation following a 2% tax on unhealthy foods: The Healthy Diné Nation Act of 2014.

INTRODUCTION: In 2014, the Navajo Nation Healthy Diné Nation Act (HDNA) was passed, combining a 2% tax on foods of 'minimal-to-no-nutritional value' and waiver of 5% sales tax on healthy foods, the first-ever such tax in the U.S. and globally among a sovereign tribal nation. The aim of this study was to measure changes in pricing and food availability in stores on the Navajo Nation following the implementation of the HDNA. METHODS: Store observations were conducted in 2013 and 2019 using the Nutrition Environment Measurement Survey-Stores (NEMS-S) adapted for the Navajo Nation. Observations included store location, type, whether healthy foods or HDNA were promoted, and availability and pricing of fresh fruits and vegetables, canned items, beverages, water, snacks and traditional foods. Differences between 2013 and 2019 and by store type and location were tested. RESULTS: The matched sample included 71 stores (51 in the Navajo Nation and 20 in border towns). In 2019, fresh produce was available in the majority of Navajo stores, with 71% selling at least 3 types of fruit and 65% selling at least 3 types of vegetables. Compared with border town convenience stores, Navajo convenience stores had greater availability of fresh vegetables and comparable availability of fresh fruit in 2019. The average cost per item of fresh fruit decreased by 13% in Navajo stores (from $0.88 to $0.76) and increased in border stores (from $0.63 to $0.73), resulting in comparable prices in Navajo and border stores in 2019. While more Navajo stores offered mutton, blue corn and wild plants in 2019 compared to 2013, these changes were not statistically significant. DISCUSSION: The findings suggest modest improvements in the Navajo store environment and high availability of fruits and vegetables. Navajo stores play an important role in the local food system and provide access to local, healthy foods for individuals living in this rural, tribal community.

Successful implementation of the Healthy Diné Nation Act in stores on the Navajo Nation.

In 2014, the Navajo Nation Council passed the Healthy Diné Nation Act (HDNA), a 2% tax on unhealthy foods and beverages and a waiver of the 5% sales tax on healthy foods and water, to support health promotion and disease prevention among the Navajo people. Very little research has assessed implementation accuracy of food or beverage taxes and none were implemented within a sovereign Tribal nation. This study assessed the accuracy of HDNA tax implementation among 47 stores located on the Navajo Nation. A pair of tax-exempt items [e.g. a bottle of water and fresh fruit] and a pair of HDNA-tax eligible items [e.g. sugary beverage and candy bar] were purchased between July-December 2019. Receipts were retained to assess taxation. A total of 87.2% of stores accurately implemented the 2% tax on unhealthy items while 55.3% of the stores accurately implemented the 6% tax waiver on healthy items. In all, 51.1% of the stores accurately applied both taxes. There were no significant differences across store type (convenience or grocery stores and trading posts) or geographic region. In conclusion, almost all stores on the Navajo Nation accurately applied a 2% tax on unhealthy foods and beverages, while the proportion of stores applying a waiver on healthy foods was lower. Successful HDNA tax implementation among stores remains an important priority in achieving the goal to support health promotion and disease prevention among Navajo communities.

The Navajo Nation Healthy Diné Nation Act: A Two Percent Tax on Foods of Minimal-to-No Nutritious Value, 2015-2019.

Our study summarizes tax revenue and disbursements from the Navajo Nation Healthy Diné Nation Act of 2014, which included a 2% tax on foods of minimal-to-no nutritional value (junk food tax), the first in the United States and in any sovereign tribal nation. Since the tax was implemented in 2015, its gross revenue has been $7.58 million, including $1,887,323 in 2016, the first full year. Revenue decreased in absolute value by 3.2% in 2017, 1.2% in 2018, and 4.6% in 2019, a significant downward trend (P = .02). Revenue allocated for wellness projects averaged $13,171 annually for each local community, with over 99% successfully disbursed and more rural areas generating significantly less revenue. Our results provide context on expected revenue, decreases over time, and feasibility for tribal and rural communities considering similar policies.

The burden of Staphylococcus aureus among Native Americans on the Navajo Nation.

INTRODUCTION: Native Americans in the southwestern United States have a higher risk for many infectious diseases and may be at higher risk for Staphylococcus aureus due to the high prevalence of risk factors for S. aureus. Recent data on invasive S. aureus infections among Native Americans are limited. METHODS: Active population- and laboratory-based surveillance was conducted in 2016-2017 on the Navajo Nation to document the rate of invasive S. aureus. A case of invasive S.aureus infection was defined as a Native American individual with S. aureus isolated from a normally sterile body site whose reported community of residence was on or around the Navajo Nation. RESULTS: One hundred and fifty-nine cases of invasive S. aureus from 152 individuals were identified. The median age of cases was 56.3 years and 35% were female. Thirty-five percent of cases had community-acquired infections. Ninety-three percent of cases had underlying medical conditions, including diabetes (60%) and obesity (42%), 28% of cases had a documented prior S. aureus infection, and 33% were infected with methicillin-resistant S. aureus. The annual incidence of invasive S. aureus and of invasive methicillin-resistant S. aureus was 64.9/100,000 persons and 21.2/100,000 persons, respectively. CONCLUSIONS: This community has a high burden of invasive S. aureus infections. Further research is needed to identify prevention strategies and opportunities for intervention.

Study of selected birth defects among American Indian/Alaska Native population: A multi-state population-based retrospective study, 1999-2007.

BACKGROUND: Higher prevalence of selected birth defects has been reported among American Indian/Alaska Native (AI/AN) newborns. We examine whether known risk factors for birth defects explain the higher prevalence observed for selected birth defects among this population. METHODS: Data from 12 population-based birth defects surveillance systems, covering a birth population of 11 million from 1999 to 2007, were used to examine prevalence of birth defects that have previously been reported to have elevated prevalence among AI/ANs. Prevalence ratios (PRs) were calculated for non-Hispanic AI/ANs and any AI/ANs (regardless of Hispanic ethnicity), adjusting for maternal age, education, diabetes, and smoking, as well as type of case-finding ascertainment surveillance system. RESULTS: After adjustment, the birth prevalence of two of seven birth defects remained significantly elevated among AI/ANs compared to non-Hispanic whites (NHWs): anotia/microtia was almost threefold higher, and cleft lip +/- cleft palate was almost 70% higher compared to NHWs. Excluding AI/AN subjects who were also Hispanic had only a negligible impact on adjusted PRs. CONCLUSIONS: Additional covariates accounted for some of the elevated birth defect prevalences among AI/ANs compared to NHWs. Exclusion of Hispanic ethnicity from the AI/AN category had little impact on birth defects prevalences in AI/ANs. NHWs serve as a viable comparison group for analysis. Birth defects among AI/ANs require additional scrutiny to identify modifiable risk and protective factors.

Exposure Characteristics of Hantavirus Pulmonary Syndrome Patients, United States, 1993-2015.

Those at highest risk are persons in occupations with potential for rodent exposure and American Indian women 40--64 years of age.

Hypervirulent emm59 Clone in Invasive Group A Streptococcus Outbreak, Southwestern United States.

The hyper-virulent emm59 genotype of invasive group A Streptococcus was identified in northern Arizona in 2015. Eighteen isolates belonging to a genomic cluster grouped most closely with recently identified isolates in New Mexico. The continued transmission of emm59 in the southwestern United States poses a public health concern.