Modelling the unidentified mortality burden from thirteen infectious pathogenic microorganisms in infants

Official statistics routinely underestimate mortality from specific microorganisms and deaths are assigned to non-specific syndromes. Here we estimate mortality attributed to specific pathogens by modelling non-specific infant deaths from laboratory reports and codes on death certificates for these pathogens, 1993-2000 in England and Wales using a generalized linear model. In total, 22 center dot 4-59 center dot 8% of non-specific deaths in infants (25-66 deaths a year) are attributable to specific pathogens. Yearly deaths from Bordetella pertussis in neonates are 6 center dot 8 [95% confidence interval (CI) 1 center dot 5-11 center dot 9]. In post-neonates 9-4 (95% CI 2 center dot 3-16 center dot 6) deaths a year are attributable to Neisseria meningitidis, 7 center dot 3 (95% CI 2-4-12-3) to Streptococcus pneumoniae, from 2 center dot 8 (95% CI 0 center dot 8-4 center dot 9) to 15 center dot 1 (95% CI 9 center dot 4-20 center dot 9) to respiratory syncytial virus (RSV) and 3 (95% CI 0 center dot 3-5 center dot 9) to parainfluenza type 2. Our results suggest there is substantial hidden mortality for a number of pathogens in infants. A considerable proportion of deaths classified to infectious syndromes are non-infectious, suggesting low specificity of death certification. Laboratory reports were the more reliable source, reinforcing the asset of strong surveillance systems.