Paediatrics (RCH) - Research Publications

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Author: Russell, Fiona × Author: Von Mollendorf, Claire × End date: 2019 × Start date: 2018 × Type: Journal Article ×

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    Determining the pneumococcal conjugate vaccine coverage required for indirect protection against vaccine-type pneumococcal carriage in low and middle-income countries: a protocol for a prospective observational study
    Chan, J ; Nguyen, CD ; Lai, JYR ; Dunne, EM ; Andrews, R ; Blyth, CC ; Datta, S ; Fox, K ; Ford, R ; Hinds, J ; La Vincente, S ; Lehmann, D ; Lim, R ; Mungun, T ; Newton, PN ; Phetsouvanh, R ; Pomat, WS ; Xeuatvongsa, A ; von Mollendorf, C ; Dance, DAB ; Satzke, C ; Muholland, K ; Russell, FM (BMJ PUBLISHING GROUP, 2018-05)
    INTRODUCTION: Pneumococcal conjugate vaccines (PCVs) prevent disease through both direct protection of vaccinated individuals and indirect protection of unvaccinated individuals by reducing nasopharyngeal (NP) carriage and transmission of vaccine-type (VT) pneumococci. While the indirect effects of PCV vaccination are well described, the PCV coverage required to achieve the indirect effects is unknown. We will investigate the relationship between PCV coverage and VT carriage among undervaccinated children using hospital-based NP pneumococcal carriage surveillance at three sites in Asia and the Pacific. METHODS AND ANALYSIS: We are recruiting cases, defined as children aged 2-59 months admitted to participating hospitals with acute respiratory infection in Lao People's Democratic Republic, Mongolia and Papua New Guinea. Thirteen-valent PCV status is obtained from written records. NP swabs are collected according to standard methods, screened using lytA qPCR and serotyped by microarray. Village-level vaccination coverage, for the resident communities of the recruited cases, is determined using administrative data or community survey. Our analysis will investigate the relationship between VT carriage among undervaccinated cases (indirect effects) and vaccine coverage using generalised estimating equations. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the relevant ethics committees at participating sites. The results are intended for publication in open-access peer-reviewed journals and will demonstrate methods suitable for low- and middle-income countries to monitor vaccine impact and inform vaccine policy makers about the PCV coverage required to achieve indirect protection.
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    Impact of the change in WHO's severe pneumonia case definition on hospitalized pneumonia epidemiology: case studies from six countries
    Russell, FM ; Reyburn, R ; Chan, J ; Tuivaga, E ; Lim, R ; Lai, J ; Hoang, MTV ; Choummanivong, M ; Sychareun, V ; Dung, KTK ; de Campo, M ; Enarson, P ; Graham, S ; La Vincente, S ; Mungan, T ; von Mollendorf, C ; Mackenzie, G ; Mulholland, K (WORLD HEALTH ORGANIZATION, 2019-06)
    OBJECTIVE: To quantify the impact of the change in definition of severe pneumonia on documented pneumonia burden. METHODS: We reviewed existing data acquired during observational hospitalized pneumonia studies, before the introduction of the pneumococcal conjugate vaccine, in infants aged 2-23 months from Fiji, Gambia, Lao People's Democratic Republic, Malawi, Mongolia and Viet Nam. We used clinical data to calculate the percentage of all-cause pneumonia hospitalizations with severe pneumonia, and with primary end-point consolidation, according to both the 2005 or 2013 World Health Organization (WHO) definitions. Where population data were available, we also calculated the incidence of severe pneumonia hospitalizations according to the different definitions. FINDINGS: At six of the seven sites, the percentages of all-cause pneumonia hospitalizations due to severe pneumonia were significantly less (P < 0.001) according to the 2013 WHO definition compared with the 2005 definition. However, the percentage of severe pneumonia hospitalizations, according to the two definitions of severe pneumonia, with primary end-point consolidation varied little within each site. The annual incidences of severe pneumonia hospitalizations per 100 000 infants were significantly less (all P < 0.001) according to the 2013 definition compared with the 2005 definition, ranging from a difference of -301.0 (95% confidence interval, CI: -405.2 to -196.8) in Fiji to -3242.6 (95% CI: -3695.2 to -2789.9) in the Gambia. CONCLUSION: The revision of WHO's definition of severe pneumonia affects pneumonia epidemiology, and hence the interpretation of any pneumonia intervention impact evaluation.