68 research outputs found

    Whom and Where Are We Not Vaccinating? Coverage after the Introduction of a New Conjugate Vaccine against Group A Meningococcus in Niger in 2010

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    MenAfriVac is a new conjugate vaccine against Neisseria meningitidis serogroup A developed for the African “meningitis belt”. In Niger, the first two phases of the MenAfriVac introduction campaign were conducted targeting 3,135,942 individuals aged 1 to 29 years in the regions of Tillabéri, Niamey, and Dosso, in September and December 2010. We evaluated the campaign and determined which sub-populations or areas had low levels of vaccination coverage in the regions of Tillabéri and Niamey. After Phase I, conducted in the Filingué district, we estimated coverage using a 30×15 cluster-sampling survey and nested lot quality assurance (LQA) analysis in the clustered samples to identify which subpopulations (defined by age 1–14/15–29 and sex) had unacceptable vaccination coverage (<70%). After Phase II, we used Clustered Lot Quality Assurance Sampling (CLQAS) to assess if any of eight districts in Niamey and Tillabéri had unacceptable vaccination coverage (<75%) and estimated overall coverage. Estimated vaccination coverage was 77.4% (95%CI: 84.6–70.2) as documented by vaccination cards and 85.5% (95% CI: 79.7–91.2) considering verbal history of vaccination for Phase I; 81.5% (95%CI: 86.1–77.0) by card and 93.4% (95% CI: 91.0–95.9) by verbal history for Phase II. Based on vaccination cards, in Filingué, we identified both the male and female adult (age 15–29) subpopulations as not reaching 70% coverage; and we identified three (one in Tillabéri and two in Niamey) out of eight districts as not reaching 75% coverage confirmed by card. Combined use of LQA and cluster sampling was useful to estimate vaccination coverage and to identify pockets with unacceptable levels of coverage (adult population and three districts). Although overall vaccination coverage was satisfactory, we recommend continuing vaccination in the areas or sub-populations with low coverage and reinforcing the social mobilization of the adult population

    Emergence of Epidemic Neisseria meningitidis Serogroup X Meningitis in Togo and Burkina Faso

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    Serogroup X meningococci (NmX) historically have caused sporadic and clustered meningitis cases in sub-Saharan Africa. To study recent NmX epidemiology, we analyzed data from population-based, sentinel and passive surveillance, and outbreak investigations of bacterial meningitis in Togo and Burkina Faso during 2006–2010. Cerebrospinal fluid specimens were analyzed by PCR. In Togo during 2006–2009, NmX accounted for 16% of the 702 confirmed bacterial meningitis cases. Kozah district experienced an NmX outbreak in March 2007 with an NmX seasonal cumulative incidence of 33/100,000. In Burkina Faso during 2007–2010, NmX accounted for 7% of the 778 confirmed bacterial meningitis cases, with an increase from 2009 to 2010 (4% to 35% of all confirmed cases, respectively). In 2010, NmX epidemics occurred in northern and central regions of Burkina Faso; the highest district cumulative incidence of NmX was estimated as 130/100,000 during March–April. Although limited to a few districts, we have documented NmX meningitis epidemics occurring with a seasonal incidence previously only reported in the meningitis belt for NmW135 and NmA, which argues for development of an NmX vaccine

    The Case for Reactive Mass Oral Cholera Vaccinations

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    Cholera outbreaks have had catastrophic impact on societies for centuries. Despite more than half a century of advocacy for safe water, sanitation and hygiene, approximately 100,000 cholera cases and 5,000 deaths were reported in Zimbabwe between August 2008 and by July 2009. Safe and effective oral cholera vaccines have been licensed and used by affluent tourists for more than a decade to prevent cholera. We asked whether oral cholera vaccines could be used to protect high risk populations at a time of cholera. We calculated how many cholera cases could have been prevented if mass cholera vaccinations would have been implemented in reaction to past cholera outbreaks. We estimate that determined, well organized mass vaccination campaigns could have prevented 34,900 (40%) cholera cases and 1,695 deaths (40%) in Zimbabwe. In the sites with endemic cholera, Kolkata and Zanzibar, a significant number of cases could have been prevented but the impact would have been less dramatic. The barriers which currently prevent the implementation of mass vaccinations, including but not only the cost to purchase the vaccine, seem insurmountable. A concerted effort of donors and key decision makers will be needed to offer better protection to populations at risk

    The Developmental Significance of Adolescent Romantic Relationships: Parent and Peer Predictors of Engagement and Quality at Age 15

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    From a longitudinal sample (n = 957; 49.9% male; 77.3% White/non-Hispanic) of participants studied from infancy through age 15, adolescents’ depth of engagement in, and quality of romantic relationships were predicted from early and contemporaneous parent–child interactive quality and peer social competence. High quality maternal parenting and peer experiences prior to and during adolescence tended to be negatively associated with the depth of engagement in this domain for the full sample, yet positively associated with the quality of adolescents’ romantic relationships for the sub-set of individuals currently dating at age 15. Results reconcile contrasting views of the origins of romantic relationship engagement and quality and the positive versus negative developmental salience of romantic relationships in adolescence

    Testing and Validation of High Density Resequencing Microarray for Broad Range Biothreat Agents Detection

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    Rapid and effective detection and identification of emerging microbiological threats and potential biowarfare agents is very challenging when using traditional culture-based methods. Contemporary molecular techniques, relying upon reverse transcription and/or polymerase chain reaction (RT-PCR/PCR) provide a rapid and effective alternative, however, such assays are generally designed and optimized to detect only a limited number of targets, and seldom are capable of differentiation among variants of detected targets. To meet these challenges, we have designed a broad-range resequencing pathogen microarray (RPM) for detection of tropical and emerging infectious agents (TEI) including biothreat agents: RPM-TEI v 1.0 (RPM-TEI). The scope of the RPM-TEI assay enables detection and differential identification of 84 types of pathogens and 13 toxin genes, including most of the class A, B and C select agents as defined by the Centers for Disease Control and Prevention (CDC, Atlanta, GA). Due to the high risks associated with handling these particular target pathogens, the sensitivity validation of the RPM-TEI has been performed using an innovative approach, in which synthetic DNA fragments are used as templates for testing the assay's limit of detection (LOD). Assay specificity and sensitivity was subsequently confirmed by testing with full-length genomic nucleic acids of selected agents. The LOD for a majority of the agents detected by RPM-TEI was determined to be at least 104 copies per test. Our results also show that the RPM-TEI assay not only detects and identifies agents, but is also able to differentiate near neighbors of the same agent types, such as closely related strains of filoviruses of the Ebola Zaire group, or the Machupo and Lassa arenaviruses. Furthermore, each RPM-TEI assay results in specimen-specific agent gene sequence information that can be used to assess pathogenicity, mutations, and virulence markers, results that are not generally available from multiplexed RT-PCR/PCR-based detection assays

    Immunogenicity of Fractional Doses of Tetravalent A/C/Y/W135 Meningococcal Polysaccharide Vaccine: Results from a Randomized Non-Inferiority Controlled Trial in Uganda

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    Meningitis are infections of the lining of the brain and spinal cord and can cause high fever, blood poisoning, and brain damage, as well as result in death in up to 10% of cases. Epidemics of meningitis occur almost every year in parts of sub-Saharan Africa, throughout a high-burden area spanning Senegal to Ethiopia dubbed the “Meningitis Belt.” Most epidemics in Africa are caused by Neisseria meningitidis (mostly serogroup A and W135). Mass vaccination campaigns attempt to control epidemics by administering meningococcal vaccines targeted against these serogroups, among others. However, global shortages of these vaccines are currently seen. We studied the use of fractional (1/5 and 1/10) doses of a licensed vaccine to assess its non-inferiority compared with the normal full dose. In a randomized trial in Uganda, we found that immune response and safety using a 1/5 dose were comparable to full dose for three serogroups (A, Y, W135), though not a fourth (C). In light of current shortages of meningococcal vaccines and their importance in fighting meningitis epidemics around the world, we suggest fractional doses be taken under consideration in mass vaccination campaigns
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