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Abstract: Background: Helicobacter pylori is one of the most common human infections in the world, and studies in Alaska Native people, as well as other Indigenous peoples, have shown a high prevalence of this gastric infection. This study was undertaken to determine the prevalence of H. pylori infection by urea breath test (UBT) and anti‐ H. pylori IgG among Alaskans living in four regions of the state and to identify factors associated with infection. Methods: A convenience sample of persons > 6 months old living in five rural and one urban Alaskan community were recruited from 1996 to 1997. Participants were asked about factors possibly associated with infection. Sera were collected and tested for anti‐ H. pylori IgG antibodies; a UBT was administered to participants > 5 years old. Results: We recruited 710 people of whom 571 (80%) were Alaska Native and 467 (66%) were from rural communities. Rural residents were more likely to be Alaska Native compared with urban residents (P < .001). Of the 710 people, 699 (98%) had a serum sample analyzed, and 634 (97%) persons > 5 years old had a UBT performed. H. pylori prevalence was 69% by UBT and 68% by anti‐ H. pylori IgG. Among those with a result for both tests, there was 94% concordance. Factors associated with H. pylori positivity were Alaska Native racial status, age ≥ 20 years, rural region of residence, living in a crowded home, and drinking water that was not piped or delivered. Conclusions: Helicobacter pylori prevalence is high in Alaska, especially in Alaska Native persons and rural residents. Concordance between UBT and serology was also high in this group. Two socioeconomic factors, crowding and drinking water that was not piped or delivered, were found to be associated with H. pylori positivity. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty-two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two-thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain. J. Med. Virol. 82:1282-1290, 2010. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Background: The highest incidence of hepatitis B virus (HBV)-associated vasculitis in the world has been reported in Alaska Natives. We examined the incidence of HBV-associated vasculitis before and after mass HBV vaccine immunization and the association between HBV genotype and vasculitis in a population-based cohort study in Alaska natives chronically infected with HBV. Methods: Genotyping was performed in vasculitis cases and 644 hepatitis B-positive controls without vasculitis using polymerase chain reaction and sequencing of the S gene. Occurrence of HBV vasculitis from 1974 to 2004 was calculated. HBV vasculitis patients and controls were also tested for basal core promoter and precore mutations. Results: Fifteen cases of HBV-associated vasculitis were identified: 13 (86%) had genotype D and one each genotype A and F. Genotype D was more commonly found in patients with vasculitis than controls [odd ratio (OR)=5.9, confidence interval (95% CI) 1.2, 21.8; P<0.015). Conclusions: HBV-associated vasculitis was associated with genotype D. [ABSTRACT FROM AUTHOR]