Browsing by Author "Kramer, Randall"

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    A longitudinal cohort study of malaria exposure and changing serostatus in a malaria endemic area of rural Tanzania
    (BioMed Central, 8/2/2017) Simmons, Ryan A.; Mboera, Leonard; Miranda, Marie L.; Morris, Alison; Stresman, Gillian; Turner, Elizabeth L.; Kramer, Randall; Drakeley, Chris; O’Meara, Wendy P.
    Abstract Background Measurements of anti-malarial antibodies are increasingly used as a proxy of transmission intensity. Most serological surveys are based on the use of cross-sectional data that, when age-stratified, approximates historical patterns of transmission within a population. Comparatively few studies leverage longitudinal data to explicitly relate individual infection events with subsequent antibody responses. Methods The occurrence of seroconversion and seroreversion events for two Plasmodium falciparum asexual stage antigens (MSP-1 and AMA-1) was examined using three annual measurements of 691 individuals from a cohort of individuals in a malaria-endemic area of rural east-central Tanzania. Mixed-effect logistic regression models were employed to determine factors associated with changes in serostatus over time. Results While the expected population-level relationship between seroprevalence and disease incidence was observed, on an individual level the relationship between individual infections and the antibody response was complex. MSP-1 antibody responses were more dynamic in response to the occurrence and resolution of infection events than AMA-1, while the latter was more correlated with consecutive infections. The MSP-1 antibody response to an observed infection seemed to decay faster over time than the corresponding AMA-1 response. Surprisingly, there was no evidence of an age effect on the occurrence of a conversion or reversion event. Conclusions While the population-level results concur with previously published sero-epidemiological surveys, the individual-level results highlight the more complex relationship between detected infections and antibody dynamics than can be analysed using cross-sectional data. The longitudinal analysis of serological data may provide a powerful tool for teasing apart the complex relationship between infection events and the corresponding immune response, thereby improving the ability to rapidly assess the success or failure of malaria control programmes.
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    Identifying barriers in the malaria control policymaking process in East Africa: insights from stakeholders and a structured literature review
    (BioMed Central, 2015) Paul, Christopher; Kramer, Randall; Lesser, Adriane; Mutero, Clifford; Miranda, Marie L.; Dickinson, Katherine
    Background: The complexity of malaria and public health policy responses presents social, financial, cultural, and institutional barriers to policymaking at multiple stages in the policy process. These barriers reduce the effectiveness of health policy in achieving national goals. Methods: We conducted a structured literature review to characterize malaria policy barriers, and we engaged stakeholders through surveys and workshops in Kenya, Tanzania, and Uganda. We compared common barriers presented in the scientific literature to barriers reported by malaria policy stakeholders. Results: The barriers identified in the structured literature review differ from those described in policymaker surveys. The malaria policy literature emphasizes barriers in the implementation stage of policymaking such as those posed by health systems and specific intervention tools. Stakeholder responses placed greater emphasis on the political nature of policymaking, the disconnect between research and policymaking, and the need for better intersectoral collaboration. Conclusions: Identifying barriers to effective malaria control activities provides opportunities to improve health and other outcomes. Such barriers can occur at multiple stages and scales. Employing a stakeholder - designed decision tool framework has the potential to improve existing policies and ultimately the functioning of malaria related institutions. Furthermore, improved coordination between malaria research and policymaking would improve the quality and efficiency of interventions leading to better population health.