The Alaska Native/American Indian experience of hepatitis C treatment with sofosbuvir-based direct-acting antivirals.

BACKGROUND: Direct-acting antiviral (DAA) drugs have been effective in the treatment of chronic hepatitis C virus (HCV) infection. Limited data are available on safety, tolerability, and efficacy in American Indian or Alaska Native people. We aim to evaluate the treatment outcomes of sofosbuvir- based regimens for treatment of HCV in a real life setting in Alaska Native/American Indian (AN/AI) people. METHODS: AN/AI patients within the Alaska Tribal Health System with confirmed positive anti-HCV and HCV RNA, who were 18 years of age and older were included in the study. Pretreatment baseline patient characteristics, treatment efficacy based on sustained virologic response (SVR) 12 weeks after treatment completion, and adverse effects were assessed. The following treatments were given according to the American Association for the Study of Liver Diseases/Infectious Disease Society of America (AASLD/IDSA) HCV Guidance: ledipasvir/sofosbuvir, sofosbuvir plus weight-based ribavirin, and sofosbuvir/velpatasvir. RESULTS: We included 501 patients with a mean age of 54.3 (range 21.3-78.3) in the study. Overall SVR was achieved in 95.2% of patients who received one of the three DAA regimens. For those with cirrhosis, overall SVR was 92.8% and for those with genotype 3 91.1% achieved SVR. The most common symptom experienced during treatment was headache. Joint pain was found to decrease during treatment. One person discontinued sofosbuvir plus ribavirin due to myocardial infarction and one discontinued sofosbuvir/velpatasvir due to urticaria. CONCLUSIONS: In the real-world setting, sofosbuvir-based treatment is safe, effective, and well tolerated in AN/AI patients. Sustained virologic response was high regardless of HCV genotype or cirrhosis status.

Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: A systematic review of prevalence and individual participant data meta-analysis of risk factors.

BACKGROUND: Colonisation with Streptococcus pneumoniae can lead to invasive pneumococcal disease and pneumonia. Pneumococcal acquisition and prevalence of colonisation are high in children. In older adults, a population susceptible to pneumococcal disease, colonisation prevalence is reported to be lower, but studies are heterogeneous. METHODS: This is a systematic review and meta-analysis of prevalence of, and risk factors for, pneumococcal colonisation in adults ≥ 60 years of age (PROSPERO #42016036891). We identified peer-reviewed studies reporting the prevalence of S. pneumoniae colonisation using MEDLINE and EMBASE (until April 2016), excluding studies of acute disease. Participant-level data on risk factors were sought from each study. FINDINGS: Of 2202 studies screened, 29 were analysable: 18 provided participant-level data (representing 6290 participants). Prevalence of detected pneumococcal colonisation was 0-39% by conventional culture methods and 3-23% by molecular methods. In a multivariate analysis, colonisation was higher in persons from nursing facilities compared with the community (odds ratio (OR) 2•30, 95% CI 1•26-4•21 and OR 7•72, 95% CI 1•15-51•85, respectively), in those who were currently smoking (OR 1•69, 95% CI 1•12-2•53) or those who had regular contact with children (OR 1•93, 95%CI 1•27-2•93). Persons living in urban areas had significantly lower carriage prevalence (OR 0•43, 95%CI 0•27-0•70). INTERPRETATION: Overall prevalence of pneumococcal colonisation in older adults was higher than expected but varied by risk factors. Future studies should further explore risk factors for colonisation, to highlight targets for focussed intervention such as pneumococcal vaccination of high-risk groups. FUNDING: No funding was required.

Increasing non-susceptibility to antibiotics within carried pneumococcal serotypes - Alaska, 2008-2015.

BACKGROUND: In Alaska, while introduction of 13-valent pneumococcal conjugate vaccine led to declines in invasive pneumococcal disease, carriage prevalence remained stable because of replacement with non-vaccine serotypes. We assessed antibiotic non-susceptibility of carried pneumococci during serotype redistribution, determined the contributions of within-serotype shifts, and assessed factors that could explain changes in non-susceptibility. METHODS: Each year from 2008 to 2015, at multiple sites in Alaska, we collected nasopharyngeal swabs and completed surveys for a convenience sample of participants. Pneumococcal serotyping and antimicrobial susceptibility testing for penicillin and erythromycin were performed. We described changes in non-susceptibility of isolates from 2008-2011 to 2012-2015, and assessed the contributions of serotype redistribution and within-serotype changes in non-susceptibility by comparing observed data to modeled data removing either factor. We used weighted logistic regression to assess whether reported risk factors could explain changes over time in non-susceptibility within serotypes. RESULTS: From 2008-2011 to 2012-2015, the overall proportion of isolates non-susceptible to penicillin or erythromycin increased by 3%, from 23% (n = 1,183) to 26% (n = 1,589; P < 0.05). However, a decrease of 3% would be expected if serotype redistribution occurred without within-serotype changes in non-susceptibility. Standardization by either factor produced hypothetical data significantly different to observed data. Within serotypes, the average annual increase in odds of non-susceptibility to penicillin or erythromycin was 1.08 (95% CI 1.05-1.11). Recent antibiotic exposure, urban residence and increased household size of participants predicted isolate non-susceptibility but did not explain the increase over time. DISCUSSION: An overall increase in non-susceptibility of carried pneumococcal isolates to penicillin or erythromycin resulted from increases in non-susceptibility within serotypes, which outweighed a protective effect of serotype redistribution. Characterization of emerging resistant clones within carried non-vaccine serotypes, including risk factors for colonization and disease, would support disease prevention efforts and inform vaccine strategies.

Hepatitis C in pregnant American Indian and Alaska native women; 2003-2015.

Recent reports have found a rise in Hepatitis C virus (HCV) infection in reproductive age women in the USA. Surveillance data suggests one group that is at increased risk of HCV infection is the American Indian and Alaska Native population (AI/AN). Using the National Center for Health Statistics (NCHS) birth certificate and the Indian Health Services, Tribal, and Urban Indian (IHS) databases, we evaluated reported cases of HCV infection in pregnant women between 2003 and 2015. In the NCHS database, 38 regions consistently reported HCV infection. The percentage of mothers who were known to have HCV infection increased between 2011 and 2015 in both the AI/AN population (0.57% to 1.19%, p < 0.001) and the non-AI/AN population (0.21% to 0.36%, p < 0.001). The IHS database confirmed these results. Individuals with hepatitis B infection or intravenous drug use (IDU) had significantly higher odds of HCV infection (OR 16.4 and 17.6, respectively). In total, 62% of HCV-positive women did not have IDU recorded. This study demonstrates a significant increase in the proportion of pregnant women infected with HCV between 2003 and 2015. This increase was greater in AI/AN women than non-AI/AN women. This highlights the need for HCV screening and prevention in pregnant AI/AN women.

Does Incorporating Change in APRI or FIB-4 Indices Over Time Improve the Accuracy of a Single Index for Identifying Liver Fibrosis in Persons With Chronic Hepatitis C Virus Infection?

BACKGROUND: The aspartate aminotransferase-to-platelet ratio index (APRI) and a fibrosis index calculated using platelets (FIB-4) have been proposed as noninvasive markers of liver fibrosis. GOALS: To determine APRI/FIB-4 accuracy for predicting histologic liver fibrosis and evaluate whether incorporating change in index improves test accuracy in hepatitis C virus (HCV)-infected Alaska Native persons. STUDY: Using liver histology as the gold standard, we determined the test characteristics of APRI to predict Metavir ≥F2 fibrosis and FIB-4 to predict Metavir ≥F3 fibrosis. Index discrimination was measured as the area under the receiver operator characteristic curve. We fit a logistic regression model to determine whether incorporating change in APRI/FIB-4 over time improved index discrimination. RESULTS: Among 283 participants, 46% were female, 48% had a body mass index >30, 11% had diabetes mellitus, 8% reported current heavy alcohol use. Participants were infected with HCV genotypes 1 (68%), 2 (17%), or 3 (15%). On liver histology, 30% of study participants had ≥F2 fibrosis and 15% had ≥F3 fibrosis. The positive predictive value of an APRI>1.5/FIB-4>3.25 for identifying fibrosis was 77%/78%. The negative predictive value of an APRI<0.5/FIB-4<1.45 was 91%/87%. The area under the receiver operator characteristic curve of an APRI/FIB-4 for identifying fibrosis was 0.82/0.84. Incorporating change in APRI/FIB-4 did not improve index discrimination. CONCLUSIONS: The accuracy of APRI/FIB-4 for identifying liver fibrosis in HCV-infected Alaska Native persons is similar to that reported in other populations and could help prioritize patients for treatment living in areas without access to liver biopsy. Change in APRI/FIB-4 was not predictive of degree of fibrosis.

Risk of end-stage liver disease, hepatocellular carcinoma, and liver-related death by fibrosis stage in the hepatitis C Alaska Cohort.

Long-term prospective studies of the outcomes associated with hepatitis C virus (HCV) infection are rare and critical for assessing the potential impact of HCV treatment. Using liver biopsy as a starting point, we analyzed the development of end-stage liver disease (ESLD), hepatocellular carcinoma (HCC), and liver-related death (LRD) according to fibrosis stage among a cohort of American Indian/Alaska Native persons in Alaska. Persons were classified as having no/mild (Ishak = 0,1), moderate (Ishak = 2), or severe (Ishak = 3,4) fibrosis or cirrhosis (Ishak = 5,6). We examined time until development of ESLD, HCC, and LRD and report survival probabilities at 3, 5, 7, and 10 years. Of 407 persons, 39% (n = 150) had no/mild fibrosis, 32% (n = 131) had moderate fibrosis, 22% (n = 88) had severe fibrosis, and 9% (n = 38) had cirrhosis. The average time of follow-up was 7.3 years. Within 5 years of biopsy, 1.7% (95% confidence interval [CI]: 0.4-6.8) of persons with no/mild fibrosis developed ESLD compared with 7.9% (95% CI, 4.0-15.2), 16.4% (95% CI, 9.6-27.2), and 49.0% (95% CI, 33.0-67.7) with moderate, severe fibrosis, and cirrhosis, respectively (P < 0.01). The 5-year outcome of HCC was 1.0% (95% CI, 0.1-7.0), 1.0% (95% CI, 0.1-6.6), 1.1% (95% CI, 0.2-7.7), and 13.4% (95% CI, 4.4-36.7) among persons with no/mild fibrosis, moderate fibrosis, severe fibrosis, and cirrhosis, respectively (P < 0.01). Five years after biopsy, 0.0% (95% CI, 0.0-14.8) of persons with no/mild fibrosis had suffered an LRD compared with 1.0% (95% CI, 0.2-7.5) of persons with moderate fibrosis, 4.7% (95% CI, 1.5-14.1) with severe fibrosis, and 16.3% (95% CI, 7.0-35.1) with cirrhosis (P < 0.01). CONCLUSION: For prevention of HCC, LRD, and ESLD in the short term, HCV therapy should target individuals who have more than mild fibrosis. (Hepatology 2017;66:37-45).

A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen.

BACKGROUND: Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined. METHODS: We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥10 mIU/mL (group 1; n = 13) or <10 mIU/mL (group 2; n = 31). RESULTS: All 44 participants, regardless of anti-HBs level, tested positive for tumor necrosis factor α, interleukin 10, or interleukin 6 production by HBV surface antigen-specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection. CONCLUSIONS: Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 32 years.

Results of interferon-based treatments in Alaska Native and American Indian population with chronic hepatitis C.

BACKGROUND: There have been few reports of hepatitis C virus (HCV) treatment results with interferon-based regimens in indigenous populations. OBJECTIVE: To determine interferon-based treatment outcome among Alaska Native and American Indian (AN/AI) population. DESIGN: In an outcomes study of 1,379 AN/AI persons with chronic HCV infection from 1995 through 2013, we examined treatment results of 189 persons treated with standard interferon, interferon plus ribavirin, pegylated interferon plus ribavirin and triple therapy with a protease inhibitor. For individuals treated with pegylated interferon and ribavirin, the effect of patient characteristics on response was also examined. RESULTS: Sustained virologic response (SVR) with standard interferon was 16.7% (3/18) and with standard interferon and ribavirin was 29.7% (11/37). Of 119 persons treated with pegylated interferon and ribavirin, 61 achieved SVR (51.3%), including 10 of 46 with genotype 1 (21.7%), 38 of 51 with genotype 2 (74.5%) and 13 of 22 with genotype 3 (59.1%). By multivariate analysis, SVR in the pegylated interferon group was associated with female sex (p=0.002), estimated duration of infection (p=0.034) and HCV genotype (p<0.0001). There was a high discontinuation rate due to side effects in those treated with pegylated interferon and ribavirin for genotype 1 (52.2%). Seven of 15 genotype 1 patients treated with pegylated interferon, ribavirin and telaprevir or boceprevir achieved SVR (46.7%). CONCLUSIONS: We had success with pegylated interferon-based treatment of AN/AI people with genotypes 2 and 3. However, there were low SVR and high discontinuation rates for those with genotype 1.

Impact of the Pneumococcal Conjugate Vaccine and Antibiotic Use on Nasopharyngeal Colonization by Antibiotic Nonsusceptible Streptococcus pneumoniae, Alaska, 2000[FIGURE DASH]2010.

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 <5 years at clinics annually during 2000-2004 and 2008-2010. PCV7 status and antibiotic use <90 days before enrollment were determined by interview/medical records review. Pneumococci were characterized by serotype and susceptibility to penicillin (PCN). Isolates with full PCN resistance (PCN-R) or intermediate PCN resistance (PCN-I) were classified as PCN-NS. RESULTS: We recruited 3496 children (median, 452 per year). During 2000-2010, a range of 18-29% per year of children used PCN/amoxicillin (P value for trend = 0.09); the proportion age-appropriately vaccinated with PCV7 increased (0[FIGURE DASH]90%; P < 0.01). Among pneumococcal isolates, the PCV7-serotype proportion decreased (53-<1%; P < 0.01) and non[FIGURE DASH]PCV7-serotype proportion increased (43-95%; P < 0.01). PCN-R pneumococcal colonization prevalence decreased (23-9%; P < 0.01) and PCN-I pneumococcal colonization prevalence increased (13-24%; P < 0.01); overall PCN-NS pneumococcal colonization prevalence was unchanged. PCN-NS among colonizing PCV7-type and non[FIGURE DASH]PCV7-type pneumococci remained unchanged; a mean of 31% per year of PCV7-type and 10% per year of non[FIGURE DASH]PCV7-type isolates were PCN-R, and 10% per year of PCV7 and 20% per year of non[FIGURE DASH]PCV7-type isolates were PCN-I. CONCLUSIONS: Overall, PCN-NS pneumococcal colonization remained unchanged during 2000-2010 because increased colonization by predominantly PCN-I non-PCV7 serotypes offset decreased colonization by predominantly PCN-R PCV7 serotypes. Proportion PCN-NS did not increase within colonizing pneumococcal serotype groups (PCV7 vs. non-PCV7) despite stable PCN use in our population.

Eighteen Years of Respiratory Syncytial Virus Surveillance: Changes in Seasonality and Hospitalization Rates in Southwestern Alaska Native Children.

BACKGROUND: Alaska Native infants from the Yukon-Kuskokwim Delta (YKD) experienced respiratory syncytial virus (RSV) hospitalization rates 5 times higher and an RSV season twice as long as the general US infant population. We describe trends in hospitalization rates and seasonality during 18 years of continuous RSV surveillance in this population and explore contributions of climate and sociodemographic factors. METHODS: We abstracted clinical and RSV test information from computerized medical records at YKD Regional Hospital and Alaska Native Medical Center from 1994 to 2012 to determine hospitalization rates and RSV season timing. Descriptive village and weather data were acquired through the US Census and Alaska Climate Research Center, University of Alaska, Fairbanks, respectively. RESULTS: During 1994-2012, YKD infant RSV hospitalization rates declined nearly 3-fold, from 177 to 65 per 1000 infants/yr. RSV season onset shifted later, from mid October to late December, contributing to a significantly decreased season duration, from 30 to 11 weeks. In a multivariate analysis, children from villages with more crowded households and lacking plumbed water had higher rates of RSV hospitalizations (relative rate, 1.17; P = 0.0005 and relative rate, 1.45; P = 0.0003). No association of temperature or dew point was found with the timing or severity of RSV season. CONCLUSIONS: Although the RSV hospitalization rate decreased 3-fold, YKD infants still experience a hospitalization rate 3-fold higher than the general US infant population. Overcrowding and lack of plumbed water were associated with RSV hospitalization. Dramatic changes occurred in RSV seasonality, not explained by changes in climate.

Effect of the 13-valent pneumococcal conjugate vaccine on nasopharyngeal colonization by Streptococcus pneumoniae--Alaska, 2008-2012.

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 <60 months at 2 urban clinics. We conducted interviews/medical records review for all participants. RESULTS: A total of 18 207 nasopharyngeal swabs (rural = 16 098; urban = 2109) were collected. From 2008 to 2012, 84% of rural and 90% of urban children age <5 years were age-appropriately vaccinated with a PCV. Overall pneumococcal colonization prevalence remained stable among rural (66%) and urban (35%) children age <5 years, and adults age ≥18 years (14%). Colonization by PCV6+ serotypes declined significantly among rural children age <5 years, urban children age <5, and adults age ≥18 over the course of the study (25%-5%, 22%-9%, 22%-6%, respectively). CONCLUSIONS: PCV13 was rapidly introduced into the Alaska childhood immunization schedule and reduced colonization by PCV6+ serotypes among children. Unvaccinated adults also experienced comparable reductions in vaccine serotype colonization indicating substantial indirect protection from PCV13.