Role of viral and bacterial pathogens in causing pneumonia among Western Australian children: a case–control study protocol

Bhuiyan, Mejbah Uddin; Snelling, Thomas L; West, Rachel; Lang, Jurissa; Rahman, Tasmina; Borland, Meredith L; Thornton, Ruth; Kirkham, Lea-Ann; Sikazwe, Chisha; Martin, Andrew C; Richmond, Peter C; Smith, David W; Jaffe, Adam; Blyth, Christopher C

The detection of microorganisms in asymptomatic children makes it more challenging to ascertain the exact contribution of any pathogen to disease with uncontrolled pneumonia aetiological studies. CAP case-control studies in children in developing countries are not generalizable to developed countries 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 [13, 17] . The Swedish study was relatively underpowered (93 x-ray confirmed cases and 240 controls) to assess attributable risk for a range of viral pathogens and in the US study, healthy controls were not enrolled contemporaneously or from all study sites which might have biased the inference for specific pathogens. The proposed study is the first case-control study of pneumonia aetiology in Australia in post-PCV vaccination era, where 250 radiologically confirmed hospitalized pneumonia cases (n=250) will be compared to 250 age-group frequency matched healthy controls for both the presence of respiratory pathogens and quantitative load of pathogens. The proposed study is expected to address the limitations from previous case-control studies through recruitment of an appropriate number of cases and controls contemporaneously and from the same study sites.