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Baltimore Highlands, MD, United States

Mehtala J.,Finnish National Institute for Health and Welfare | Antonio M.,Medical Research Council Unit | Kaltoft M.S.,Statens Serum Institute | O'Brien K.L.,Center for American Indian Health | Auranen K.,Finnish National Institute for Health and Welfare
Epidemiology | Year: 2013

BACKGROUND:: Vaccine-induced replacement by nonvaccine serotypes in pneumococcal colonization and disease poses a threat to the long-term effectiveness of pneumococcal vaccination. One of the main drivers for serotype replacement is likely to be the competitive interactions between pneumococcal serotypes. METHODS:: We used longitudinal datasets of pneumococcal colonization among infants (American Indian and The Gambia) and toddlers (Denmark) to study the strength and mechanism of competition between pneumococcal serotypes. We characterized the strength of competition as the relative reduction in the expected time spent colonized with two serotypes (double colonization) as compared with colonization with no competition. We also assessed the mechanism of competition, that is, whether reduction in double colonization is due to reduced rate of acquisition or enhanced clearance of colonization. The three datasets were analyzed assuming both perfect (100%) and imperfect (50%) sensitivity in detection of double colonization. RESULTS:: Each dataset showed strong between-serotype competition, and competition in acquisition was clearly identified. These findings remained in the secondary analysis assuming only 50% sensitivity to detect double colonization. Inferences about enhanced clearance due to competition were susceptible to the assumed sensitivity of detection. CONCLUSIONS:: Strong competition between pneumococcal serotypes can explain the prompt replacement by the nonvaccine serotypes in vaccinated persons and populations. The main mechanism of between-serotype interaction was identified as competition in acquisition, which suggests that replacement in pneumococcal disease depends largely on propensities of the replacing serotypes to cause disease through acquisition of colonization. Copyright © 2013 by Lippincott Williams & Wilkins. Source

Harer M.W.,University of Wisconsin - Madison | Yaeger J.P.,Center for American Indian Health
Wisconsin Medical Journal | Year: 2014

Background: Cardiopulmonary resuscitation (CPR) can increase survival in instances of sudden cardiac arrest. Nationally, high school coaches are the first responders to sudden cardiac arrest in up to one-third of high school athlete collapses, but little is known about the status of their CPR certification. The primary goal of this study was to assess the proportion of Wisconsin high school coaches that are certified in CPR. Methods: A prospective web-based survey was developed and distributed to high school athletic directors in Wisconsin. Results: Seventy-eight percent of respondents reported that coaches are the primary responders to a collapse. The majority of high schools do not require CPR certification and only 50% of coaches are currently CPR certified. Athletic directors with greater than 12 years of experience were the most likely to have an emergency action plan in place (P = 0.004). Conclusion: In Wisconsin, the proportion of coaches who act as the primary responder to a collapse is greater than previously reported. Although the majority of coaches in Wisconsin serve as the primary responder to an episode of sudden cardiac arrest, only about 50% are CPR certified. Due to the severe consequences of sudden cardiac arrest, CPR certification among coaches should be required. © 2014 Wisconsin Medical Society. Source

An international consultation was convened in March 2012 to provide feedback on the Case for Carriage, a summary statement by the Pneumococcal Carriage Consortium (PneumoCarr) proposing nasopharyngeal (NP) colonization as a supplementary or alternative endpoint in vaccine licensure. PneumoCarr members provided information to vaccine manufacturers, regulators and the WHO on the evidence for NP carriage as a precursor to pneumococcal disease, standardization of laboratory methods for the detection of multiple serotype carriage, definition and estimation of pneumococcal vaccine efficacy against carriage (VE-col), and the direct and indirect impact of vaccination on carriage. Manufacturers and regulators had the opportunity to respond to the information compiled by PneumoCarr and share their perspectives. VE-col as a licensure endpoint may be more useful for the next generation pneumococcal vaccine products, particularly those for which the immunological correlate of protection is not established, whereas it may be less needed for pneumococcal conjugate vaccines which have an established licensure pathway. The consultation supported the importance of NP carriage data as a critical element linking vaccine impact on the individual direct risk of disease to the population-level impact: indirect effects such as herd protection and serotype replacement. The indirect effects of vaccination, however, are not currently established as part of the licensure process and to include them would be a paradigm shift for regulatory agencies who currently consider this information in the post-licensure setting. More discussion and consensus-building is needed around the rationale and optimal mechanism to include carriage data in the licensure pathway for new pneumococcal vaccines. The WHO and national advisory groups on immunization policy may have an important role in considering the evidence for the indirect benefit of vaccination as informed by its impact on NP carriage. © 2013 Elsevier Ltd. Source

Davis S.M.,International Vaccine Access Center | Deloria-Knoll M.,International Vaccine Access Center | Kassa H.T.,International Vaccine Access Center | O'Brien K.L.,International Vaccine Access Center | O'Brien K.L.,Center for American Indian Health
Vaccine | Year: 2013

Background: Invasive disease due to Streptococcus pneumoniae remains an important worldwide cause of morbidity and mortality, particularly in young children and the elderly. The development and use of pneumococcal conjugate vaccines (PCVs) have had a dramatic impact on rates of vaccine-type invasive pneumococcal disease (IPD) not only in the pediatric population targeted for vaccination but in non-vaccinated age-groups as well. This indirect effect is directly mediated by a reduction of vaccine-type nasopharyngeal carriage and thus transmission by vaccinated children. Current PCV licensing procedures do not take into consideration nasopharyngeal carriage impact, and thus the indirect effect. This review summarizes the evidence for the indirect effect of PCV on vaccine-type disease and its correlation with changes in carriage among unvaccinated populations, to assess the basis for inclusion of carriage in the PCV licensing process. Methods: Randomized controlled trials, surveillance and other observational studies published between 1994 and 2013 were systematically identified from global, regional and review databases and conference abstracts. We included as primary evidence, studies in non-vaccinated groups addressing changes in both vaccine-type IPD and carriage between pre- and post-PCV introduction periods; studies missing one of these four components were included as supporting rather than primary evidence. Results: We identified studies from 14 countries, nearly all developed countries. Vaccine-type IPD and carriage in non-targeted populations consistently decreased after PCV introduction, with the magnitude of decrease growing over time. Where IPD and carriage were observed in the same population, VT-decreases occurred contemporaneously. These relationships held true across age-groups and between indigenous and non-indigenous populations in the US and Australia. Conclusions: Indirect PCV impact on VT-IPD and VT-carriage has been significant. Impact on carriage should be considered for inclusion in the PCV licensure process as a predictor of indirect effects. © 2013. Source

Weatherholtz R.,Center for American Indian Health | Millar E.V.,Center for American Indian Health | Moulton L.H.,Center for American Indian Health | Reid R.,Center for American Indian Health | And 5 more authors.
Clinical Infectious Diseases | Year: 2010

Background. Before 7-valent pneumococcal conjugate vaccine (PCV7) introduction, invasive pneumococcal disease (IPD) rates among Navajo were several-fold those of the general US population. Only 50% of IPD cases in children involved PCV7 serotypes. Methods. We conducted active, population-based surveillance for IPD for the period 1995-2006. We documented case characteristics and serotyped the isolates. Results. Over 12-year period, we identified 1508 IPD cases, 447 of which occurred in children aged <5 years. Rates of IPD due to vaccine serotypes among children aged <1 year, 1 to <2 years, and 2 to <5 years decreased from 210, 263, and 51 cases per 100,000 population, respectively in 1995-1997 to 0 cases in 2004-2006 (P<.001). Among adults aged 3=65 years, rates of IPD due to vaccine serotypes decreased 81% (95% confidence interval, -98% to -9%; P = .02). Rates of nonvaccine serotype IPD were unchanged in all age strata except for persons aged 18 to <40 years, among whom the rate decreased by 35% from 27 to 18 cases per 100,000 population (95% confidence interval, -57% to -1%; P = .03). Conclusions. Vaccine-serotype IPD has virtually been eliminated in the PCV7 era among Navajo of all ages. Overall rates of nonvaccine-serotype IPD have not increased, although increases have occurred for some individual types. Rates of all-serotype IPD among Navajo children remain 3-5-fold greater than in the general US population. © 2010 by the Infectious Diseases Society of America. All rights reserved. Source

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