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Objective In the United States, HPV vaccination is routinely recommended at age 11 or 12 years; the series can be started at age 9. We conducted a cohort study to assess long-term immunogenicity of quadrivalent HPV vaccine (4vHPV) in an American Indian/Alaska Native (AI/AN) Indigenous population. Methods During 2011–2014, we enrolled AI/AN girls and boys aged 9–14 years, who were vaccinated with a 3-dose series of 4vHPV. Serum specimens were collected at five time points: immediately prior to doses 2 and 3, and at one month, one year, and two years after series completion. Antibody testing was performed using a multiplex virus-like-particle-IgG ELISA for 4vHPV types (HPV 6/11/16/18). Results Among 477 children (405 girls/72 boys) completing the 3-dose series, median age at enrollment was 11.2 years. Of the 477, 72 (15%) were tested before dose 2 and 70 (15%) before dose 3. Following series completion, 435 (91%) were tested at one month, 382 (80%) at one year, and 351 (74%) at two years. All tested participants had detectable antibody to 4vHPV types at all time points measured. Geometric mean concentrations (GMCs) for 4vHPV types at one month and two years post-series completion were 269.9 and 32.7 AU/ml for HPV6, 349.3 and 42.9 AU/ml for HPV11, 1240.2 and 168.3 IU/ml HPV16, and 493.2 and 52.2 IU/ml for HPV18. Among children tested after each dose, GMCs after doses 1 and 2 were 3.9 and 32.2 AU/ml for HPV6, 5.3 and 45.6 AU/ml for HPV11, 20.8 and 187.9 IU/ml for HPV16; and 6.6 and 49.7 IU/ml for HPV18. No serious adverse events were reported. Conclusion All AI/AN children developed antibodies to all 4vHPV types after vaccination. GMCs rose after each dose, then decreased to a plateau over the subsequent two years. This cohort will continue to be followed to determine duration of antibody response.

The duration of protection from hepatitis B vaccination in children and adults is not known. In 1981, we used three doses of plasma-derived hepatitis B vaccine to immunize a cohort of 1578 Alaska Native adults and children from 15 Alaska communities who were ≥6 months old.We tested persons for antibody to hepatitis B surface antigen (anti-HBs) levels 35 years after receiving the primary series. Those with levels10 mIU/ml received one booster dose of recombinant hepatitis B vaccine 2-4 weeks later and were then evaluated on the basis of anti-HBs measurements 30 days postbooster. Among the 320 recruited, 112 persons had not participated in the 22- or 30-year follow-up study (group 1), and 208 persons had participated but were not given an HBV booster dose (group 2). Among the 112 persons in group 1 who responded to the original primary series, 53 (47.3%) had an anti-HBs level ≥10 mIU/ml. Among group 1, 73.7% (28 of 38) of persons available for a booster dose responded to it with an anti-HBs level ≥10 mIU/ml at 30 days. Initial anti-HBs level after the primary series was correlated with higher anti-HBs levels at 35 years. Among 8 persons who tested positive for antibody to hepatitis B core antigen, none tested positive for HBsAg or HBV DNA.Based on anti-HBs level ≥10 mIU/ml at 35 years and a 73.7% booster dose response, we estimate that 86% of participants had evidence of protection 35 years later. Booster doses are not needed in the general population at this time.

Introduction. Gastric cancer is a health disparity in the Alaska Native people. The incidence of Helicobacter pylori infection, a risk factor for non-cardia gastric adenocarcinoma, is also high. Gastric cancer is partially associated with the virulence of the infecting strain. Aim. To genotype the vacA s, m and i and cag pathogenicity island (cagPAI) genes in H. pylori from Alaskans and investigate associations with gastropathy. Methodology. We enrolled patients with gastritis, peptic ulcer disease (PUD) and intestinal metaplasia (IM) in 1998–2005 and patients with gastric cancer in 2011–2013. Gastric biopsies were collected and cultured and PCR was performed to detect the presence of the right and left ends of the cagPAI, the cagA, cagE, cagT and virD4 genes and to genotype the vacA s, m and i regions. Results. We recruited 263 people; 22 (8 %) had no/mild gastritis, 121 (46 %) had moderate gastritis, 40 (15%) had severe gastritis, 38 (14 %) had PUD, 30 (11 %) had IM and 12 (5 %) had gastric cancer. H. pylori isolates from 150 (57%) people had an intact cagPAI; those were associated with a more severe gastropathy (P≤0.02 for all comparisons). H. pylori isolates from 77 % of people had either the vacA s1/i1/m1 (40 %; 94/234) or s2/i2/m2 (37 %; 86/234) genotype. vacA s1/i1/m1 was associated with a more severe gastropathy (P≤0.03 for all comparisons). Conclusions. In this population with high rates of gastric cancer, we found that just over half of the H. pylori contained an intact cagPAI and 40 % had the vacA s1/i1/m1 genotype. Infection with these strains was associated with a more severe gastropathy.

BACKGROUND The pneumococcal conjugate vaccine (PCV) was introduced in 2001. Widespread PCV use nearly eradicated pneumococcal colonization by vaccine serotypes. Since 2008, however, colonization by PCV-serotype 19F has increased in Alaska residents. We describe the epidemiology of re-emerging serotype 19F colonization. METHODS We conducted annual cross-sectional colonization surveys from 2008 to 2013. We recruited children aged

BACKGROUND: In 2016, we detected an outbreak of group A Streptococcus (GAS) invasive infections among the estimated 1000 persons experiencing homelessness (PEH) in Anchorage, Alaska. We characterized the outbreak and implemented a mass antibiotic intervention at homeless service facilities. METHODS: We identified cases through the Alaska GAS laboratory-based surveillance system. We conducted emm-typing, antimicrobial susceptibility testing, and whole genome sequencing (WGS) on all invasive isolates and compared medical record data of patients infected with emm26.3 and other emm types. In February 2017, we offered PEH at six facilities in Anchorage a single dose of 1 gram of azithromycin. We collected oropharyngeal and non-intact skin swabs on a subset of participants concurrent with the intervention and 4 weeks afterward. RESULTS: From July 2016–April 2017, we detected 42 invasive emm26.3 cases in Anchorage, 35 of which were in PEH. The emm26.3 isolates differed on average by only 2 single nucleotide polymorphisms. Compared to other emm types, infection with emm26.3 was associated with cellulitis (odds ratio [OR] 2.5, p=0.04) and necrotizing fasciitis (OR 4.4, p=0.02). We dispensed antibiotics to 391 PEH. Colonization with emm26.3 decreased from 4% of 277 at baseline to 1% of 287 at follow-up (p=0.05). Invasive GAS incidence decreased from 1.5 cases per 1000 PEH/week in the 6 weeks prior to the intervention to 0.2 cases per 1000 PEH/week in the 6 weeks after (p=0.01). CONCLUSIONS: In an invasive GAS outbreak in PEH in Anchorage, mass antibiotic administration was temporally associated with reduced invasive disease cases and colonization prevalence.

BackgroundBetween May and July 2018, 4 Haemophilus influenzae serotype a (Hia) infections occurred in a remote Alaska community. We performed a public health response to prevent further illness and understand Hia carriage.MethodsWe collected oropharyngeal samples community-wide to evaluate baseline carriage. Risk factors were evaluated by interview. We offered prophylactic rifampin to individuals in contact with invasive Hia patients (contacts) and to all children aged ResultsAt baseline, 4 of 27 (14.8%) contacts and 7 of 364 (1.9%) noncontacts (P < .01) carried Hia. Contacts aged ConclusionsHia carriage prevalence was significantly higher among contacts than noncontacts. Rifampin prophylaxis did not result in a reduction of Hia carriage prevalence in this community.

Here we describe the relationships between serotypes, genotypes, and antimicrobial susceptibility among isolates causing invasive pneumococcal disease in Alaskan children during the pneumococcal conjugate vaccine (PCV) era. From 2001 to 2013 we received 271 isolates representing 33 serotypes. The most common serotypes were 19A (29.5%, n= 80), 7F (12.5%, n= 34), 15B/C (6.3%, n= 17), and 22F (4.8%, n= 13). Multilocus sequence typing identified 11 clonal complexes (CC) and 45 singletons. Five CCs accounted for 52% (141/271) of the total: CC199 (21% [n= 57], serotypes 19A, 15B/C), CC191 (12.2% [n= 33], serotype 7F), CC172 (10.3% [n= 28], serotypes 19A, 23A, 23B), CC433 (4.4% [n= 12], serotype 22F), and CC100 (4.4% [n= 12], serotype 33F). The proportion of isolates nonsusceptible to erythromycin and tetracycline increased after 13-valent PCV use (14% [n= 30] versus 29% [n= 14]; P= 0.010) and (4% [n= 9] versus 22% [n= 11]; P< 0.001), respectively. The genetic diversity also increased after 13-valent PCV use (Simpson’s diversity index =0.95 versus 0.91; P= 0.022).

Background: Due to their close relationship with the environment, Alaskans are at risk for zoonotic pathogen infection. One way to assess a population's disease burden is to determine the ...

The Arctic Investigations Program (AIP) began surveillance for invasive group A streptococcal (GAS) infections in Alaska in 2000 as part of the invasive bacterial diseases population-based laboratory surveillance program. Between 2001 and 2013, there were 516 cases of GAS infection reported, for an overall annual incidence of 5.8 cases per 100,000 persons with 56 deaths (case fatality rate, 10.7%). Of the 516 confirmed cases of invasive GAS infection, 422 (82%) had isolates available for laboratory analysis. All isolates were susceptible to penicillin, cefotaxime, and levofloxacin. Resistance to tetracycline, erythromycin, and clindamycin was seen in 11% ( n = 8), 5.8% ( n = 20), and 1.2% ( n = 4) of the isolates, respectively. A total of 51 emm types were identified, of which emm 1 (11.1%) was the most prevalent, followed by emm 82 (8.8%), emm 49 (7.8%), emm 12 and emm 3 (6.6% each), emm 89 (6.2%), emm 108 (5.5%), emm 28 (4.7%), emm 92 (4%), and emm 41 (3.8%). The five most common emm types accounted for 41% of isolates. The emm types in the proposed 26-valent and 30-valent vaccines accounted for 56% and 78% of all cases, respectively. GAS remains an important cause of invasive bacterial disease in Alaska. Continued surveillance of GAS infections will help improve understanding of the epidemiology of invasive disease, with an impact on disease control, notification of outbreaks, and vaccine development.

BACKGROUND We describe the relative impact of the heptavalent pneumococcal conjugate vaccine (PCV7, introduced 2001) and antibiotic use on colonization by antibiotic-resistant pneumococci in urban Alaskan children during 2000-2010. METHODS We obtained nasopharyngeal swab specimens from a convenience sample of children aged

BackgroundAlaska Native (AN) children have experienced high rates of invasive pneumococcal disease (IPD). In March 2010, PCV13 was introduced statewide in Alaska. We evaluated the impact of PCV13 on IPD in children and adults, 45 months after introduction.MethodsPneumococcal sterile site isolates, reported through state-wide surveillance, were serotyped using standard methods. We defined a pre-PCV13 time period 2005–2008 and post-PCV13 time period April 2010–December 2013; excluding Jan 2009–March 2010 because PCV13 was introduced pre-licensure in one high-risk region in 2009.ResultsAmong Alaska children

Background Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from Asia to many countries. Objectives We conducted a cross-sectional seroepidemiological survey in Anchorage and western Alaska to identify possible behaviors associated with migratory bird exposure and measure seropositivity to HPAI H5N1. Methods We enrolled rural subsistence bird hunters and their families, urban sport hunters, wildlife biologists, and a comparison group without bird contact. We interviewed participants regarding their exposures to wild birds and collected blood to perform serologic testing for antibodies against a clade 2.2 HPAI H5N1 virus strain. Results Hunters and wildlife biologists reported exposures to wild migratory birds that may confer risk of infection with avian influenza A viruses, although none of the 916 participants had evidence of seropositivity to HPAI H5N1. Conclusions We characterized wild bird contact among Alaskans and behaviors that may influence risk of infection with avian influenza A viruses. Such knowledge can inform surveillance and risk communication surrounding HPAI H5N1 and other influenza viruses in a population with exposure to wild birds at a crossroads of intercontinental migratory flyways.

BACKGROUND. Alaska Native children have high invasive pneumococcal disease (IPD) rates, and lack of in-home running water has been shown to have a significant association with infection. Pneumococcal conjugate vaccines reduced IPD; however, this population saw substantial replacement disease and colonization with nonvaccine serotypes. We evaluated risk factors for nasopharyngeal pneumococcal colonization in Alaska Native adults and children. METHODS. We conducted annual surveys from 2008 through 2011 of residents of all ages in 8 rural Alaskan villages. Interviews were conducted, medical charts were reviewed, and nasopharyngeal swabs were cultured for Streptococcus pneumoniae. Multivariate logistic regression models were developed for 3 age groups (under 10 years, 10–17 years, and 18 years and older) to determine risk factors for colonization. RESULTS. We obtained 12 535 nasopharyngeal swabs from 4980 participants. Our population lived in severely crowded conditions, and 48% of households lacked in-home running water. In children

Before introduction of Haemophilus influenzae type b (Hib) vaccines, rates of Hib disease in Alaska's indigenous people were among the highest in the world. Vaccination reduced rates dramatically; however, invasive H. influenzae type a (Hia) disease has emerged. Cases of invasive disease were identified through Alaska statewide surveillance during 1983-2011. Of 866 isolates analyzed for serotype, 32 (4%) were Hia. No Hia disease was identified before 2002; 32 cases occurred during 2002-2011 (p

Helicobacter pylori infection is more common in Alaska Native persons than in the general U.S. population, with seroprevalence to H. pylori approaching 75%. Previous studies in Alaska have demonstrated elevated proportions of antimicrobial resistance among H. pylori isolates. We analyzed H. pylori data from the Centers for Disease Control and Prevention's sentinel surveillance in Alaska from January 2000 to December 2008 to determine the proportion of culture-positive biopsy specimens with antimicrobial resistance from Alaska Native persons undergoing endoscopy. The aim of the present study was to monitor antimicrobial resistance of H. pylori isolates over time and by region in Alaska Native persons. Susceptibility testing of H. pylori isolates to metronidazole, clarithromycin, amoxicillin, and tetracycline was performed using agar dilution. Susceptibility testing for levofloxacin was performed by Etest. Overall, 45% (532/1,181) of persons undergoing upper endoscopy were culture positive for H. pylori . Metronidazole resistance was demonstrated in isolates from 222/531 (42%) persons, clarithromycin resistance in 159/531 (30%) persons, amoxicillin resistance in 10/531 (2%) persons, and levofloxacin resistance in 30/155 (19%) persons; no tetracycline resistance was documented. The prevalence of metronidazole, clarithromycin, and levofloxacin resistance varied by region. Female patients were more likely than male patients to demonstrate metronidazole ( P < 0.05) and clarithromycin ( P < 0.05) resistance. No substantial change in the proportion of persons with resistant isolates was observed over time. Resistance to metronidazole, clarithromycin, and levofloxacin is more common among H. pylori isolates from Alaska Native persons than those from elsewhere in the United States.

Helicobacter pylori infection is common in Alaska. The development of severe H. pylori disease is partially determined by the virulence of the infecting strain. Here we present vacA and cagA genotype data for H. pylori strains isolated from Alaskans and their correlation with clinical disease. We enrolled patients scheduled for esophagogastroduodenoscopy and positive for H. pylori infection. Gastric biopsy specimens from the stomach antrum and fundus were cultured. We performed PCR analysis of the H. pylori vacA gene and for the presence of the cagA gene and cagA empty site. We genotyped 515 H. pylori samples from 220 Native and 66 non-Native Alaskans. We detected the cagA gene in 242/286 (85%) persons; of 222 strains that could be subtyped, 95% (212) were non-Asian cagA and 3% (6) were East Asian cagA . After removing mixed infections ( n = 17), 83% of H. pylori strains had either the vacA s1m1 (120/269) or s2m2 (103/269) genotype. Sixty-six percent (68/103) of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. Infection with an H. pylori strain having the cagA gene or vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with a decreased risk of esophagitis ( P = 0.003 and 0.0003, respectively). Infection with an H. pylori strain having the vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with an increased risk of peptic ulcer disease (PUD) ( P = 0.003). The majority of H. pylori strains in this study carried the non-Asian cagA gene and either the vacA s1m1 or s2m2 genotype. A majority of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. There was an association of H. pylori genotype with esophagitis and PUD.

Alaska Native people have suffered disproportionately from previous influenza pandemics. We evaluated 3 separate syndromic data sources to determine temporal and geographic patterns of spread of 2009 pandemic influenza A H1N1 (pH1N1) in Alaska, and reviewed records from persons hospitalized with pH1N1 disease in 3 areas in Alaska to characterize clinical and epidemiologic features of disease in Alaskans. A wave of pH1N1 disease swept through Alaska beginning in most areas in August or early September. In rural regions, where Alaska Native people comprise a substantial proportion of the population, disease occurred earlier than in other regions. Alaska Native people and Asian/Pacific Islanders (A/PI) were 2-4 times more likely to be hospitalized than whites. Alaska Native people and other minorities remain at high risk for early and substantial morbidity from pandemic influenza episodes. These findings should be integrated into plans for distribution and use of vaccine and antiviral agents.

The impact of heptavalent pneumococcal conjugate vaccine (PCV7) on transmission of antimicrobial-resistant Streptococcus pneumoniae is an important concern for countries considering PCV7 introduction.Every winter from 2000 to 2004, as PCV7 was routinely introduced, we obtained nasopharyngeal swabs for pneumococcal culture, serotyping, and susceptibility testing from 150 children aged 3-59 months at each of 3 Anchorage, Alaska clinics. We assessed risk factors for pneumococcal carriage, including vaccination status and antimicrobial use.Between 2000 and 2004, 2250 nasopharyngeal swabs from 2061 infants and children were collected. The proportion of children receivingor = 1 PCV7 vaccination increased from 0 to 89%, whereas overall pneumococcal carriage remained stable (38% versus 41%, respectively). Among S. pneumoniae carriers, we observed declines in carriage of PCV7 serotypes (from 54% to 10%, P0.01) and trimethoprim-sulfamethoxazole nonsusceptible strains (44% to 16%, P0.01), but not in PCN-nonsusceptible strains (36% versus 37%). Among PCN-nonsusceptible types, the proportion of serotype 19A strains increased from 10% to 32% (P = 0.0002). Recent beta-lactam use was stable throughout the period (29% overall), whereas trimethoprim-sulfamethoxazole use declined from 6% to 2% (P = 0.02).PCV7 vaccination in the first 5 years did not affect overall pneumococcal carriage, but was associated with a shift in serotype distribution from PCV7 types to non-PCV7 types. With persistent pressure of some antimicrobials, reductions in carriage of antimicrobial nonsusceptible PCV7 types may be offset by increases in carriage of nonsusceptible non-PCV7 types.

Alaska Native persons have age-adjusted invasive pneumococcal disease (IPD) rates two- to three-fold greater than non-Native Alaskans. To characterize IPD epidemiology and 23-valent polysaccharide pneumococcal vaccine (PPV-23) effectiveness in Alaska Native adults we reviewed IPD cases from Alaska-wide, laboratory-based surveillance. Sterile site isolates were serotyped. Vaccine effectiveness (VE) was estimated using the indirect cohort method. 394 cases (44.5 cases/100,000/year) occurred in 374 Alaska Native adults (36.0% agedor =55 years). Underlying conditions included heavy alcohol use (65.7%), smoking (60.8%) and COPD (25.0%). Overall VE was 75% (95% confidence interval [CI]: 27%, 91%) but declined with increasing age; for personsor =55 years (VE=0; 95% CI:0, 78%; p=0.713). Alaska Native adults experience high rates of IPD. The majority of IPD cases occurred in persons with underlying conditions and behaviors associated with increased risk of IPD in other populations. PPV-23 vaccine effectiveness was confirmed in younger Alaska Native adults but not among adultsor =55 years.

The relationship between prior fluoroquinolone use and levofloxacin resistance in Helicobacter pylori infection is unknown. Among 125 enrolled patients, 8.8% had H. pylori isolates that were resistant to levofloxacin. Levofloxacin resistance was associated with any prior fluoroquinolone use over the previous 10 years and with the total number of fluoroquinolone courses prescribed (P < .001).

BACKGROUND The duration of protection in children and adults resulting from hepatitis B vaccination is unknown. In 1981, we immunized a cohort of 1578 Alaska Native adults and children from 15 Alaska communities aged ≥6 months using 3 doses of plasma-derived hepatitis B vaccine. METHODS Persons were tested for antibody to hepatitis B surface antigen (anti-HBs) levels 30 years after receiving the primary series. Those with levels

Background: Previous studies in Alaska have demonstrated elevated proportions of antimicrobial resistance among Helicobacter pylori isolates. Materials and Methods: We analyzed H. pylori data from the Centers for Disease Control and Prevention (CDC)'s sentinel surveillance in Alaska from July 1999 to June 2003 to determine the proportion of culture-positive biopsies from Alaska Native persons undergoing routine upper-endoscopy, and the susceptibility of H. pylori isolates to metronidazole [minimum inhibitory concentration (MIC) of > 8 g metronidazole/mL), clarithromycin (MIC ≥ 1), tetracycline (MIC ≥ 2) and amoxicillin (MIC ≥ 1)] using agar dilution. Results: Nine-hundred sixty-four biopsy specimens were obtained from 687 participants; 352 (51%) patients tested culture positive. Mean age of both culture-positive and culture-negative patients was 51 years. Metronidazole resistance was demonstrated in isolates from 155 (44%) persons, clarithromycin resistance from 108 (31%) persons, amoxicillin resistance from 8 (2%) persons, and 0 for tetracycline resistance. Metronidazole and clarithromycin resistance varied by geographic region. Female patients were more likely than male subjects to show metronidazole resistance (p

From 1998 to 2000, 13 rural Alaskan villages (population, 3326) were surveyed annually by nasopharyngeal cultures for Streptococcus pneumoniae carriage. Data regarding antibiotic use for the entire population was abstracted from clinic records. In 1999, education of medical providers and the community about appropriate antibiotic use began in 4 villages; this program was expanded to include all villages in 2000. Antibiotic courses per person decreased by 31% in the initial intervention villages and by 35% in the remaining villages after education (P

Changes in pneumococcal serotype-specific carriage and invasive pneumococcal disease (IPD) after the introduction of pneumococcal conjugate vaccine (PCV7) could inform serotype epidemiology patterns following the introduction of newer conjugate vaccines.We used data from statewide IPD surveillance and annual pneumococcal carriage studies in four regions of Alaska to calculate serotype-specific invasiveness ratios (IR; odds ratio of a carried serotype's likelihood to cause invasive disease compared to other serotypes) in children5 years of age. We describe changes in carriage, disease burden, and invasiveness between two time periods, the pre-PCV7 period (1996-2000) and the late post-PCV7 period (2006-2009).Incidence of IPD decreased from the pre- to post-vaccine period (95.7 vs. 57.2 cases per 100,000 children, P0.001), with a 99% reduction in PCV7 disease. Carriage prevalence did not change between the two periods (49% vs. 50%), although PCV7 serotype carriage declined by 97%, and non-vaccine serotypes increased in prevalence. Alaska pre-vaccine IRs corresponded to pooled results from eight pre-vaccine comparator studies (Spearman's rho=0.44, P=0.002) and to the Alaska post-vaccine period (Spearman's rho=0.28, P=0.029). Relatively invasive serotypes (IR1) caused 66% of IPD in both periods, although fewer serotypes with IR1 remained in the post-vaccine (n=9) than the pre-vaccine period (n=13).After PCV7 introduction, serotype IRs changed little, and four of the most invasive serotypes were nearly eliminated. If PCV13 use leads to a reduction of carriage and IPD for the 13 vaccine serotypes, the overall IPD rate should further decline.The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

BACKGROUND In 2010, a 13-valent pneumococcal conjugate vaccine (PCV13) replaced a 7-valent vaccine (PCV7) that contained all PCV7 serotypes plus 6 additional serotypes (PCV6+). We conducted annual surveys from 2008 to 2012 to determine the effect of PCV13 on colonization by pneumococcal serotypes. METHODS We obtained nasopharyngeal swabs for pneumococcal identification and serotyping from residents of all ages at 8 rural villages and children age

The rapid emergence of antibiotic-resistant pneumococcal strains has reduced treatment options. The aim of this study was to determine antimicrobial susceptibilities, serotype distributions, and molecular resistance mechanisms among macrolide-resistant invasive pneumococcal isolates in Alaska from 1986 to 2010. We identified cases of invasive pneumococcal disease in Alaska from 1986 to 2010 through statewide population-based laboratory surveillance. All invasive pneumococcal isolates submitted to the Arctic Investigations Program laboratory were confirmed by standard microbiological methods and serotyped by slide agglutination and the Quellung reaction. MICs were determined by the broth microdilution method, and macrolide-resistant genotypes were determined by multiplex PCR. Among 2,923 invasive pneumococcal isolates recovered from 1986 to 2010, 270 (9.2%) were nonsusceptible to erythromycin; 177 (66%) erythromycin-nonsusceptible isolates demonstrated coresistance to penicillin, and 167 (62%) were multidrug resistant. The most frequent serotypes among the macrolide-resistant isolates were serotypes 6B (23.3%), 14 (20.7%), 19A (16.7%), 9V (8.9%), 19F (6.3%), 6A (5.6%), and 23F (4.8%). mef and erm (B) genes were detected in 207 (77%) and 32 (12%) of the isolates, respectively. Nineteen (7%) of the erythromycin-nonsusceptible isolates contained both mef and erm (B) genotypes; 15 were of serotype 19A. There was significant year-to-year variation in the proportion of isolates that were nonsusceptible to erythromycin ( P < 0.001). Macrolide resistance among pneumococcal isolates from Alaska is mediated predominantly by mef genes, and this has not changed significantly over time. However, there was a statistically significant increase in the proportion of isolates that possess both erm (B) and mef , primarily due to serotype 19A isolates.

Introduction. Recent epidemiologic research studies in rural Alaska have examined risk factors for infectious diseases collected at the household level. Examples include the health effects of in-home piped water and household air quality. Because the exposure is measured at the household level, it is necessary to determine if participants remained in the same house throughout the course of follow-up. Methods. We used data from a pneumococcal nasopharyngeal carriage study in 8 rural Alaska villages [3 regions; average number of persons: 642 (min 210, max 720 per village) to quantify changes in household membership and individual movements from 2008 to 2010. We define a household as a group of individuals living in a home together. Because the same households participated in carriage surveys over several years, we could determine changes on an annual basis. We calculated the percentage of households with a ≥1 person change in household members from year to year. Additionally, we present the percentage of individuals that changed households during consecutive years. Results. In 3 regions of Alaska, the average household size was 5 persons. Between 2008 and 2009, 50% (250/497) of households had a change in their membership (≥1 person in-migrated or out-migrated). Fiftythree percent of households experienced some migration of their members between 2009 and 2010. A total of 27 and 15% of households had a change of ≥2 and ≥3 persons, respectively. The percentage of households with movement was similar among the 3 rural regions and varied from 42 to 63% between villages. At the individual level, an average of 11% of persons changed households between years. The group with the most movement between houses was persons 18-29 years of age (19%), and least movement was in 5-10 and 50-64 years of age (6%). There was no difference in movement by gender. Conclusions. In rural Alaska, 52% of households experienced movement of members between years and 11% of individuals change households. These are important demographic figures to consider when planning and designing studies that measure an epidemiological exposure at the household level. Power and sample size calculations should account for the loss to follow-up associated with in- and out-migration of individuals from households. Keywords: household; migration; intervention; crowding; rural; sample size; exposure; power (Published: 5 August 2013) This paper is part of Supplement 1, 2013, ICCH15 Proceedings . More papers from this Supplement can be found here . Citation: Int J Circumpolar Health 2013, 72 : 21229 - http://dx.doi.org/10.3402/ijch.v72i0.21229

Background In July 2016, invasive infections caused by a rare subtype of group A Streptococcus (iGAS; subtype emm26.3) were detected among the estimated 700–1000 homeless persons in Anchorage, Alaska. An increase in case numbers of emm26.3 iGAS was detected in October, including one death. We implemented a mass antibiotic intervention at homeless service facilities in Anchorage to prevent further cases of emm26.3 iGAS. Methods We defined cases as the isolation of emm26.3 GAS from a normally sterile body site, or nonsterile sites in the case of necrotizing fasciitis or toxic shock syndrome. We identified cases through routine laboratory-based surveillance and conducted antimicrobial susceptibility testing on all invasive isolates. From February 13–18, 2017, we evaluated persons accessing homeless services at six facilities in Anchorage and offered a single oral dose of 1 gram of azithromycin for iGAS prophylaxis. We concurrently collected oropharyngeal (OP) and wound swab specimens on a subset of participants. The swab collection was repeated at the same locations 4 weeks after the intervention. Swabs were cultured for GAS and emm-typed. Results From October 1, 2016 through February 18, 2017, we detected 31 cases among homeless persons. All emm26.3 iGAS isolates were erythromycin susceptible. We evaluated 484 persons at homeless services facilities and provided azithromycin to 394 (81%). Of 289 swab participants, 9 (3.1%) had baseline emm26.3 OP colonization. Of participants with wounds, 3/71 (4.2%) had emm26.3 wound colonization. At follow-up, 3/298 (1.0%) participants had emm26.3 OP colonization and 1/63 (1.6%) had emm26.3 wound colonization (P-value for change in any colonization = 0.05). Colonization by other emm-types, primarily erythromycin non-susceptible emm11, was 5.1% at baseline and 5.0% at follow-up. In the 6 weeks post-intervention, we detected 1 case among homeless persons (0.2 cases/week post- vs. 1.6 cases/week pre-intervention, P = 0.01 for change). Conclusion We reached a substantial proportion of the Anchorage homeless population with an antibiotic intervention to prevent iGAS. While possible that the outbreak was waning, the intervention was temporally associated with reduced case counts and colonization prevalence. Disclosures All authors: No reported disclosures.

We investigated serotype 6A/6C invasive pneumococcal disease (IPD) incidence, genetic diversity, and carriage before and after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in Alaska. IPD cases (1986–2009) were identified through population-based laboratory surveillance. Isolates were initially serotyped by conventional methods, and 6C isolates were differentiated from 6A by polymerase chain reaction. Among invasive and carriage isolates initially typed as 6A, 35% and 50% were identified as 6C, respectively. IPD rates caused by serotype 6A or 6C among children

AIM: To evaluate the accuracy of two non-invasive tests in a population of Alaska Native persons. High rates of Helicobacter pylori (H. pylori) infection, H. pylori treatment failure, and gastric cancer in this population necessitate documentation of infection status at multiple time points over a patient’s life. METHODS: In 280 patients undergoing endoscopy, H. pylori was diagnosed by culture, histology, rapid urease test, 13C urea breath test (UBT), and immunoglobulin G antibodies to H. pylori in serum. The performances of 13C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori test by culture or, in case of a negative culture result, by positive histology and a positive rapid urease test. RESULTS: The sensitivity and specificity of the 13C-UBT were 93% and 88%, respectively, relative to the gold standard. The antibody test had an equivalent sensitivity of 93% with a reduced specificity of 68%. The false positive results for the antibody test were associated with previous treatment for an H. pylori infection [relative risk (RR) = 2.8]. High levels of antibodies to H. pylori were associated with chronic gastritis and male gender, while high scores in the 13C-UBT test were associated with older age and with the H. pylori bacteria load on histological examination (RR = 4.4). CONCLUSION: The 13C-UBT outperformed the antibody test for H. pylori and could be used when a non-invasive test is clinically necessary to document treatment outcome or when monitoring for reinfection.

Alaska Native (AN) children, especially those in the Yukon-Kuskokwim region (YK-AN children), suffer some of the highest rates of invasive pneumococcal disease (IPD) in the world. Rates of IPD declined after statewide introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2001, but increased in subsequent years.Population-based laboratory surveillance data (1986-2007) for invasive Streptococcus pneumoniae infection in Alaskan children5 years old were used to evaluate the association of IPD rates and serotype distribution with immunization, socioeconomic status, and in-home water service.Introduction of PCV7 vaccine resulted in elimination of IPD caused by vaccine serotypes, but was followed by increasing rates of IPD caused by nonvaccine serotypes. Among YK-AN children IPD rates dropped by 60%, but then rose due to non-PCV7 serotypes to levels 5- to 10-fold higher than rates in non-YK-AN children and non-AN children. IPD rates in YK-AN children were twice as high in villages where10% of houses had in-home piped water compared with villages where more than 80% of houses had in-home piped water (390 cases/100,000 vs. 146 cases/100,000, P = 0.008).High IPD rates in Alaska are associated with lack of in-home piped water (controlling for household crowding and per capita income). The effect of in-home piped water is most likely mediated through reduced water supply leading to limitations on handwashing.

Background. Use of heptavalent protein-polysaccharide pneumococcal conjugate vaccine (PCV7) has been associated with decreases in PCV7-type invasive pneumococcal disease and nasopharyngeal (NP) carriage in children. Vaccine use has also indirectly decreased the rate of invasive disease in adults, presumably through decreased transmission of pneumococci from vaccinated children to adults. Methods. We conducted NP carriage surveys in 8 villages in Alaska in 1998-2004. Streptococcus pneumoniae isolates were characterized by serotype and antimicrobial susceptibility. We analyzed trends in serotype distribution, antibiotic resistance, and factors associated with adult carriage of PCV7-serotype pneumococci before and after the introduction of PCV7 in 2001. Results. We collected 15,598 NP swabs; overall, 52% of adults living in the villages surveyed participated in the colonization study. The proportion of adult carriers with PCV7-type pneumococcal carriage decreased from 28% of carriers in 1998-2000 to 4.5% of carriers in 2004 (P

We evaluated invasive pneumococcal disease (IPD), antimicrobial resistance and nasopharyngeal colonization before and after introduction of pneumococcal conjugate vaccine (PCV7) in Alaska Natives (AN), a population with high IPD rates. We obtained IPD rates from population-based surveillance. Colonization was determined from annual surveys among rural AN of all ages and from urban children. After vaccine introduction, vaccine-type IPD rates declined by 91% among AN children

Helicobacter pylori antibodies were measured over 24 months in American Indian and Alaska Native persons who cleared their infections. Two months after treatment, 82% of H. pylori -negative persons remained seropositive. While there were declines in H. pylori antibodies for 12 months, after 24 months 71% of persons remained seropositive.

ContextWith routine childhood vaccination using heptavalent pneumococcal conjugate vaccine, one concern has been the potential for emergence and expansion of replacement disease caused by serotypes not contained in the heptavalent conjugate vaccine.ObjectiveTo determine whether replacement disease is associated with the overall decline in invasive pneumococcal disease among Alaska Native children.Design, Setting, and PatientsAlaska statewide longitudinal population-based laboratory surveillance of invasive Streptococcus pneumoniae infections from January 1, 1995, through December 31, 2006.Main Outcome MeasuresIncidence and types of pneumococcal disease in children younger than 2 years.ResultsIn the first 3 years after introduction of routine vaccination with heptavalent pneumococcal conjugate vaccine, overall invasive pneumococcal disease decreased 67% in Alaska Native children younger than 2 years (from 403.2 per 100 000 in 1995-2000 to 134.3 per 100 000 per year in 2001-2003, P

The relationship between previous antimicrobial treatments and infection with drug-resistant Helicobacter pylori is unknown.To determine whether previous use of antimicrobial agents predicts subsequent antibiotic resistance of H. pylori and whether resistance affects treatment outcome.Retrospective cohort analysis of adults recruited sequentially from a clinical practice.A referral hospital in Anchorage, Alaska.125 adults infected with H. pylori.Medical records were reviewed for antimicrobial agents prescribed in the 10 years before diagnosis with H. pylori infection. Antimicrobial susceptibility of H. pylori isolates obtained from endoscopic gastric biopsy was determined by using agar dilution. Cure was determined by using the urea breath test 2 months after antimicrobial treatment.Among the 125 patients, 37 (30%) were found to have H. pylori isolates resistant to clarithromycin and 83 (66%) were found to have H. pylori isolates resistant to metronidazole. Resistance to clarithromycin was associated with previous use of any macrolide antibiotic (P0.001), and resistance to metronidazole was associated with previous use of metronidazole (P0.001). The odds of isolates being resistant to clarithromycin increased in relation to the number of courses of macrolides received (P0.001). Among 53 persons treated with clarithromycin-based regimens, treatment failed in 77% of those carrying clarithromycin-resistant H. pylori (10 of 13) and 13% of those with clarithromycin-susceptible strains (5 of 40) (relative risk, 6.2 [95% CI, 1.9 to 37.1]; P0.001).Previous use of macrolides and metronidazole is associated with H. pylori resistant to these antimicrobial agents. Clarithromycin resistance is associated with a greater risk for failure with clarithromycin-based treatments.