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David Scheifele Scott Halperin Barbara Law Arlene King for The Canadian Paediatric Society / Health Canada Immunization Monitoring Program Active 《CMAJ》2005,172(1):53-56
Background
Although vaccination of infants against Haemophilus influenzae type b (Hib) invasive infections is effective and has been routinely available in Canada since 1992, cases of the disease continue to occur. We were interested in determining whether recent cases of Hib infection reflected progressive loss of protection with time since vaccination, increasing nonacceptance of vaccination or a deleterious effect of coadministration of recently introduced vaccines such as those for pneumococcal and meningococcal conjugates and hepatitis B. We report on the causes of Hib infections among vaccinated and unvaccinated children between 2001 and 2003 in Canada.Methods
Through our established network of 12 pediatric tertiary care hospitals we actively searched for cases in each centre by reviewing daily admissions and laboratory reports, visiting the wards and checking discharge diagnosis codes. Culture-confirmed cases were summarized by nurse monitors using a standardized reporting system.Results
We identified 29 cases during the 3 years: 16 in 2001, 10 in 2002 and 3 in 2003. Half of the 29 patients had meningitis. Hib infection was more common among children less than 6 months of age (11 cases) and in boys (20 cases). Two deaths occurred (7% case-fatality ratio). A total of 20 children had received no or incomplete primary vaccination because of parental refusal (7 cases), because they were too young to have completed the primary series (11 cases, including 1 in which parental refusal was also a factor) or because of delays in completing the primary series (2 cases); the vaccination history was uncertain in the remaining case. Infection despite primary vaccination occurred in 9 children: 2 previously healthy children and 7 who were immunocompromised or who had a predisposing condition. None of the cases identified in 2003 involved children who had received any of the newly introduced vaccines.Interpretation
Invasive Hib infections remain rare in Canada, with most cases occurring in children too young to have completed the primary series. Protection after vaccination appears to extend into later childhood and does not appear to be diminished by coadministration of newer infant vaccines.Until recently Haemophilus influenzae type b (Hib) was a leading cause of meningitis, epiglottitis and other invasive infections in children, affecting about 1 child in 250 by 5 years of age.1 The risk of infection was highest among children 6–24 months of age. Antibodies directed against the Hib capsular polysaccharide (polyribosyl ribitol phosphate, PRP) form the basis of protection. PRP protein conjugate vaccines that elicit anti-PRP responses in young infants have been used in Canada since 1992. Doses are recommended at 2, 4 and 6 months of age to establish protection and at 18 months to reinforce it. Since 1995 all provinces have used the same Hib vaccine (a PRP–tetanus protein conjugate [PRP-T], produced by Aventis Pasteur), in combination products based on whole-cell pertussis vaccines (from 1995 to 1997) or acellular pertussis vaccines (1998 to the present).Invasive Hib infections have been monitored since 1992 by a network of Canadian pediatric hospitals known as the Immunization Monitoring Program, Active (IMPACT).2 In 1985, before the first Hib vaccine was licensed, 485 invasive Hib cases were seen at 10 centres (those participating in IMPACT when the “look-back” was done).3 Case totals fell progressively as better vaccines became available.3,4,5 In 2000, only 4 cases were recorded by the IMPACT centres (which by then numbered 12), 99% fewer than in 1985.6 Continuing surveillance is important to assess the effectiveness of the current schedule and vaccine. Because Hib vaccination is relatively new, the question of duration of protection remains open. Resurgence of Hib disease occurred recently in the United Kingdom,7 prompting addition of a booster dose to the vaccination schedule (as in Canada). Other questions of relevance are whether nonacceptance of Hib vaccine is influencing case totals and whether coadministration of newer vaccines, such as those for pneumococcal and meningococcal group C conjugates and hepatitis B, is adversely affecting Hib responses. A reduced response is most likely to occur when infants are given conjugate vaccines containing the same carrier protein,8 which is not the case with PRP-T and pneumococcal conjugate vaccines; however, their compatibility has not been formally demonstrated to date. In this report we present details of cases encountered by IMPACT in the period 2001 to 2003. 相似文献96.
Oliveira DM Gouveia JJ Diniz NB Pacheco AC Vasconcelos EJ Diniz MC Viana DA Ferreira TD Albuquerque MC Fortier DC Maia AR Costa LA Melo JO da Silva MC Walter CA Faria JO Tome AR Gomes MJ Oliveira SM Araújo-Filho R Costa RB Maggioni R;PROGENE The Brazilian Northeast Genome Program 《Omics : a journal of integrative biology》2005,9(2):173-193
The trypanosomatid flagellar apparatus contains conventional and unique features, whose roles in infectivity are still enigmatic. Although the flagellum and the flagellar pocket are critical organelles responsible for all vesicular trafficking between the cytoplasm and cell surface, still very little is known about their roles in pathogenesis and how molecules get to and from the flagellar pocket. The ongoing analysis of the genome sequences and proteome profiles of Leishmania major and L infantum, Trypanosoma cruzi, T. brucei, and T. gambiensi ( www.genedb.org ), coupled with our own work on L. chagasi (as part of the Brazilian Northeast Genome Program- www.progene.ufpe.br ), prompted us to scrutinize flagellar genes and proteins of Leishmania spp. promastigotes that could be virulence factors in leishmaniasis. We have identified some overlooked parasite factors such as the MNUDC-1 (a protein involved in nuclear development and genomic fusion) and SQS (an enzyme of sterol biosynthesis), among the described flagellar gene families. A database concerning the results of this work, as well as of other studies of Leishmania and its organelles, is available at http://nugen.lcc.uece.br/LPGate . It will serve as a convenient bioinformatics resource on genomics and pathology of the etiological agents of leishmaniasis. 相似文献
97.
Land use change in the Amazon estuary: Patterns of caboclo settlement and landscape management 总被引:2,自引:0,他引:2
Eduardo S. Brondizio Ph.D. Program Emilio F. Moran Paul Mausel You Wu Ph.D. Program 《Human ecology: an interdisciplinary journal》1994,22(3):249-278
Landsat TM scenes for 1985 and 1991 are used to produce a georeferenced map of land cover and land use for an area of the Amazon estuary inhabited by three populations of caboclos with distinct patterns of land use. This information is combined in a geographic information system with ethnographic and survey research carried out over the past 5 years to develop representative spectral signatures which permit measurement and differentiation of land uses and the detection of change even between small areas of managed floodplain forest and unmanaged forest, and between three distinct age/growth classes of secondary succession following deforestation. Implementation of these procedures permit the scaling up or down of research at different resolutions. Three distinct patterns of land use are examined with differential impact on the environment. Mechanized agriculture at one site has eliminated virtually all the mature upland forest and is now dominated by secondary successional vegetation. The more traditional system of diversified land use at the next site shows a subtle cycling of flooded forest to managed palm forest through time in response to the price of palm fruit and cycling in the use of fallow land. A third site, based on palm fruit extractivism, shows minimal changes in land cover due to persistent specialization on management of flooded forest extraction. There is little evidence that the community with the greatest impact on forest cover is any better off economically than the two communities which have minimal impact on the landscape. This study suggests how a balance between use and conservation in Amazonia may be achieved in floodplain and estuarine areas, and the effectiveness of monitoring these types of land cover from satellite platforms. 相似文献
98.
Matthew S. Freiberg Ionut Bebu Russell Tracy Kaku So-Armah Jason Okulicz Anuradha Ganesan Adam Armstrong Thomas O’Bryan David Rimland Amy C. Justice Brian K. Agan Infectious Disease Clinical Research Program HIV Working Group 《PloS one》2016,11(4)
The mechanism underlying the excess risk of non-AIDS diseases among HIV infected people is unclear. HIV associated inflammation/hypercoagulability likely plays a role. While antiretroviral therapy (ART) may return this process to pre-HIV levels, this has not been directly demonstrated. We analyzed data/specimens on 249 HIV+ participants from the US Military HIV Natural History Study, a prospective, multicenter observational cohort of >5600 active duty military personnel and beneficiaries living with HIV. We used stored blood specimens to measure D-dimer and Interleukin-6 (IL-6) at three time points: pre-HIV seroconversion, ≥6 months post-HIV seroconversion but prior to ART initiation, and ≥6 months post-ART with documented HIV viral suppression on two successive evaluations. We evaluated the changes in biomarker levels between time points, and the association between these biomarker changes and future non-AIDS events. During a median follow-up of 3.7 years, there were 28 incident non-AIDS diseases. At ART initiation, the median CD4 count was 361cells/mm3; median duration of documented HIV infection 392 days; median time on ART was 354 days. Adjusted mean percent increase in D-dimer levels from pre-seroconversion to post-ART was 75.1% (95% confidence interval 24.6–148.0, p = 0.002). This increase in D-dimer was associated with a significant 22% increase risk of future non-AIDS events (p = 0.03). Changes in IL-6 levels across time points were small and not associated with future non-AIDS events. In conclusion, ART initiation and HIV viral suppression does not eliminate HIV associated elevation in D-dimer levels. This residual pathology is associated with an increased risk of future non-AIDS diseases. 相似文献
99.
Biology Education Research Group 《Journal of biological education》2012,46(4):176-180
This paper presents the results of an extended evaluation programme designed to test the effectiveness of text-based flexible learning as a replacement to 30 – 50% of the lectures in certain modules in conventional undergraduate courses within the School of Life Sciences at Napier University. For examinations in which students answered both types of question, marks for questions based on topics taught by flexible learning were equivalent to marks for questions based on topics taught by conventional teaching methods. Marks for examinations in which at least 50% of the answers were based on topics taught by flexible learning were equivalent to marks for examinations in which questions were based on topics taught by conventional teaching methods. Rates of achievement of a mark of 40% or more at first attempt for examinations in which at least 50% of the answers were based on topics taught by flexible learning were significantly better than rates of achievement of a mark of 40% or more at first attempt for questions based on topics taught by conventional teaching methods. Students gave positive feedback on flexible learning, both verbally and by questionnaire, and showed highly significant bias in favour of topics taught by flexible learning in their choice of questions in examinations. The flexible learning programme studied here has satisfied the various quality assurance criteria in place within the University throughout the time that it has been in operation. The evaluation has demonstrated that the textbased flexible learning programme studied here was an effective alternative to lectures. 相似文献
100.
Mary K. Grabowski Justin Lessler Andrew D. Redd Joseph Kagaayi Oliver Laeyendecker Anthony Ndyanabo Martha I. Nelson Derek A. T. Cummings John Baptiste Bwanika Amy C. Mueller Steven J. Reynolds Supriya Munshaw Stuart C. Ray Tom Lutalo Jordyn Manucci Aaron A. R. Tobian Larry W. Chang Chris Beyrer Jacky M. Jennings Fred Nalugoda David Serwadda Maria J. Wawer Thomas C. Quinn Ronald H. Gray the Rakai Health Sciences Program 《PLoS medicine》2014,11(3)