Prabhu P. Gounder

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.

Impact of the 13-valent pneumococcal conjugate vaccine (pcv13) on invasive pneumococcal disease and carriage in Alaska.

BACKGROUND Alaska 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. METHODS Pneumococcal 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. RESULTS Among Alaska children <5 years, PCV13 serotypes comprised 65% of IPD in the pre-PCV13 period and 26% in the PCV13 period. Among all Alaska children <5 years, IPD rates decreased from 60.9 (pre) to 25.4 (post) per 100,000/year (P<0.001); PCV13 serotype IPD decreased from 37.7 to 6.4 (P<0.001). Among AN children <5 years, IPD rates decreased from 149.2 to 60.8 (P<0.001); PCV13 serotype IPD decreased from 87.0 to 17.4 (P<0.001); non-PCV13 serotype IPD did not change significantly. Among persons 5-17 and ≥45 years, the post-vaccine IPD rate was similar to the baseline period, but declined in persons 18-44 years (39%, P<0.001); this decline was similar in AN and non-AN persons (38%, P=0.016, 43%, P=0.014, respectively). CONCLUSIONS Forty-five months after PCV13 introduction, overall IPD and PCV13-serotype IPD rates had decreased 58% and 83%, respectively, in Alaska children <5 years of age when compared with 2005-2008. We observed evidence of indirect effect among adults with a 39% reduction in IPD among persons 18-44 years.

Climate change and infectious diseases in the Arctic: establishment of a circumpolar working group.

The Arctic, even more so than other parts of the world, has warmed substantially over the past few decades. Temperature and humidity influence the rate of development, survival and reproduction of pathogens and thus the incidence and prevalence of many infectious diseases. Higher temperatures may also allow infected host species to survive winters in larger numbers, increase the population size and expand their habitat range. The impact of these changes on human disease in the Arctic has not been fully evaluated. There is concern that climate change may shift the geographic and temporal distribution of a range of infectious diseases. Many infectious diseases are climate sensitive, where their emergence in a region is dependent on climate-related ecological changes. Most are zoonotic diseases, and can be spread between humans and animals by arthropod vectors, water, soil, wild or domestic animals. Potentially climate-sensitive zoonotic pathogens of circumpolar concern include Brucella spp., Toxoplasma gondii, Trichinella spp., Clostridium botulinum, Francisella tularensis, Borrelia burgdorferi, Bacillus anthracis, Echinococcus spp., Leptospira spp., Giardia spp., Cryptosporida spp., Coxiella burnetti, rabies virus, West Nile virus, Hantaviruses, and tick-borne encephalitis viruses.

Nested Case-Control Study: Hepatocellular Carcinoma Risk After Hepatitis B Surface Antigen Seroclearance

Hepatocellular carcinoma (HCC) risk after resolving chronic hepatitis B virus (HBV) infection is unclear.

Epidemiology of bacterial meningitis in the North American Arctic, 2000–2010

OBJECTIVE To determine the incidence of meningitis caused by Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae in the North American Arctic during 2000-2010. METHODS Surveillance data were obtained from the International Circumpolar Surveillance network. We defined a case of bacterial meningitis caused by H. influenzae, N. meningitidis, or S. pneumoniae as a culture-positive isolate obtained from a normally sterile site in a resident with a meningitis diagnosis. RESULTS The annual incidence/100,000 persons for meningitis caused by H. influenzae, N. meningitidis, and S. pneumoniae among all North American Arctic residents was: 0.6, 0.5, and 1.5, respectively; the meningitis incidence among indigenous persons in Alaska and Canada (indigenous status not recorded in Greenland) for those three bacteria was: 2.1, 0.8, and 2.4, respectively. The percentage of pneumococcal isolates belonging to a 7-valent pneumococcal conjugate vaccine serotype declined from 2000-2004 to 2005-2010 (31%-2%, p-value <0.01). During 2005-2010, serotype a caused 55% of H. influenzae meningitis and serogroup B caused 86% of meningococcal meningitis. CONCLUSIONS Compared with all North American Arctic residents, indigenous people suffer disproportionately from bacterial meningitis. Arctic residents could benefit from the development of an H. influenzae serotype a vaccine and implementation of a meningococcal serogroup B vaccine.

Infection With Hepatitis C Virus Genotype 3 Is an Independent Risk Factor for End-Stage Liver Disease, Hepatocellular Carcinoma, and Liver-Related Death

BACKGROUND & AIMS Few studies have examined factors associated with disease progression in hepatitis C virus (HCV) infection. We examined the association of 11 risk factors with adverse outcomes in a population‐based prospective cohort observational study of Alaska Native/American Indian persons with chronic HCV infection. METHODS We collected data from a population‐based cohort study of liver‐related adverse outcomes of infection in American Indian/Alaska Native persons with chronic HCV living in Alaska, recruited from 1995 through 2012. We calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) for end‐stage liver disease (ESLD; presence of ascites, esophageal varices, hepatic encephalopathy, or coagulopathy), hepatocellular carcinoma (HCC), and liver‐related death using a Cox proportional hazards model. RESULTS We enrolled 1080 participants followed up for 11,171 person‐years (mean, 10.3 person‐years); 66%, 19%, and 14% were infected with HCV genotypes 1, 2, and 3, respectively. On multivariate analysis, persons infected with HCV genotype 3 had a significantly increased risk of developing all 3 adverse outcomes. Their aHR for ESLD was 2.1 (95% CI, 1.5–3.0), their aHR for HCC was 3.1 (95% CI, 1.4–6.6), and their aHR for liver‐related death was 2.4 (95% CI, 1.5–4.0) compared with genotype 1. Heavy alcohol use was an age‐adjusted risk factor for ESLD (aHR, 2.2; 95% CI, 1.6–3.2), and liver‐related death (aHR, 2.9; 95% CI, 1.8–4.6). Obesity was a risk factor for ESLD (aHR, 1.4; 95% CI, 1.0–1.9), and diabetes was a risk factor for ESLD (aHR, 1.5; 95% CI, 1.1–2.2). Male sex was a risk factor for HCC (aHR, 3.6; 95% CI, 1.6–8.2). CONCLUSIONS In a population‐based cohort study of American Indian/Alaska Native persons with chronic HCV infection, we found those infected with HCV genotype 3 to be at high risk for ESLD, HCC, and liver‐related death.

Incidence of hepatocellular carcinoma according to hepatitis B virus genotype in Alaska Native people

Most regions of the world have ≤3 co‐circulating hepatitis B virus (HBV) genotypes, which limits direct comparisons of hepatocellular carcinoma (HCC) risk among HBV‐infected persons by genotype. We evaluated HCC incidence by HBV genotype in a cohort of Alaska Native (AN) persons where five HBV genotypes (A, B, C, D, F) have been identified.

Medication injection safety knowledge and practices among anesthesiologists: New York State, 2011

STUDY OBJECTIVE To survey anesthesiologists to assess medication injection safety knowledge and practices, and to improve infection control programs of the New York City Department of Health and Mental Hygiene and the New York State Society of Anesthesiologists (NYSSA). DESIGN Survey instrument. SETTING Scientific Educational and Professional Development Program Office, Centers for Disease Control and Prevention, Atlanta, GA, USA. MEASUREMENTS A confidential, 23-question survey was emailed to a total of 2,310 NYSSA members. Data from the survey were culled from the responses of NYSSA members who practiced in New York State only. MAIN RESULTS Of the 607 survey respondents, 595 met inclusion criteria (response rate 26%). Of these, 94% to 99% correctly answered 4 categories of questions about injection-contamination mechanisms. Respondents reported unacceptable practices (eg, not using a new needle and syringe for each new patient [3%]; not using a new needle and syringe to access medication vials [28%]; and combining vial content leftovers [11%]). Resident physicians reported these unacceptable practices more often than attending physicians. Use of medication vials for multiple patients (permitted for multi-dose vials but a potentially high-risk practice) was reported by 49% of respondents and was more common among those who worked in outpatient settings. Reported barriers to using a new medication vial for each new patient were medication shortages (44%), reduction of waste (44%), and cost (27%). Unacceptable or potentially high-risk practices were more common among respondents who reported ≥ one barrier. CONCLUSIONS Although they were not necessarily representative of all anesthesiologists in New York State, unacceptable or high-risk injection practices were common among respondents despite widespread knowledge regarding injection-contamination mechanisms. System barriers contribute to the use of medication vials for multiple patients.

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).

Hepatocellular Carcinoma Risk in Alaska Native Children and Young Adults with Hepatitis B Virus: Retrospective Cohort Analysis

OBJECTIVES To evaluate the hepatocellular carcinoma (HCC) risk in Alaska Native children and young adults with hepatitis B virus (HBV). STUDY DESIGN Retrospective analysis of a population-based cohort of Alaska Native persons with HBV followed during 1982-2012. All individuals with HBV were offered HCC screening regardless of age using alpha-fetoprotein every 6 months; persons with an elevated alpha-fetoprotein or persons at high-risk for HCC, such as cirrhosis, family history of HCC, were offered ultrasound. We calculated the HCC incidence/1000 person-years from date of cohort entry until death, diagnosis of HCC, or attaining the age of 40 years (males) or 50 years (females). RESULTS We followed 1083 subjects with HBV (56% male) comprising 5 genotypes (A2 [12.5%], B6 [1.7%], C [5.3%], D [49.7%], F1 [18.6%], unknown [12.4%]) for a median of 23.4 years/person. We observed 22 HCC cases (incidence/1000 person-years follow-up: 1.0); 19 HCC cases among persons with genotype F1. There was no significant difference in HCC incidence between males (1.4) and females (0.6). The HCC incidence was significantly higher for persons with genotype F1 (4.4) compared with genotype A2 (0.4) and D (0.2) and remained higher among persons with HBV genotype F1 excluding persons with HCC family history/cirrhosis (1.9). CONCLUSIONS Alaska Native children and young adults with HBV genotype F1 are at high risk for HCC and should receive HCC surveillance. For males <40 years of age and females <50 years of age with HBV in regions of the world with a high genotype F prevalence, testing/confirming genotype F can identify persons who could benefit from HCC surveillance.