Child pneumonia at a time of epidemiological transition
Authors: Harry Campbell, Harish Nair
Journal: The Lancet Global Health (2015)

Some important changes have occurred in global child health in the past decade. Socioeconomic development, action to address the broad social determinants of health,1Feng XL Theodoratou E Liu L et al.Social, economic, political and health system and program determinants of child mortality reduction in China between 1990 and 2006: a systematic analysis.J Glob Health. 2012; 2: 010405PubMed Google Scholar and the development and implementation of effective child health interventions2Bhutta ZA Das JK Walker N et al.for the Lancet Diarrhoea and Pneumonia Interventions Study GroupInterventions to address deaths from childhood pneumonia and diarrhoea equitably: what works and at what cost?.Lancet. 2013; 381: 1417-1429Summary Full Text Full Text PDF PubMed Scopus (345) Google Scholar have resulted in a steady and substantial fall in global child mortality.3Liu L Johnson HL Cousens S et al.for the Child Health Epidemiology Reference Group of WHO and UNICEFGlobal, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000.Lancet. 2012; 379: 2151-2161Summary Full Text Full Text PDF PubMed Scopus (2774) Google Scholar Mortality due to pneumonia, the leading cause of child death in the past decade, has fallen the most steeply. These changes have also resulted in a changing pattern of pneumonia incidence, cause, and risk-factor effects. Therefore, particularly at this time, reliable information about the epidemiology of pneumonia in low-income and middle-income countries should be collected, disseminated, and used to inform child health policy and priority setting. Since vital statistics and other routine health information are not widely available in the countries and regions with the highest child disease burden, to a large extent researchers are reliant on well designed and implemented population-based research in these settings to provide this essential information. The excellent birth cohort study reported in The Lancet Global Health by Heather Zar and colleagues,4le Roux DM Myer L Nicol MP Zar HJ Incidence and severity of childhood pneumonia in the first year of life in a South African birth cohort: the Drakenstein Child Health Study.Lancet Glob Health. 2015; 3: 95-103Summary Full Text Full Text PDF Scopus (87) Google Scholar done in a periurban area outside Cape Town in South Africa, is a good example of a study that has provided important information about child pneumonia at a time of change. It provides the first incidence estimates of pneumonia and severe pneumonia in a low-to-middle-income country (LMIC) population, with high coverage of both (13 valent) pneumococcal and Haemophilus influenzae type b conjugate vaccines, and with roughly a fifth of the cohort being HIV-exposed but uninfected. On a background of falling pneumonia incidence over the past decade,5Rudan I O'Brien KL Nair H et al.for the Child Health Epidemiology Reference Group (CHERG)Epidemiology and etiology of childhood pneumonia in 2010: estimates of incidence, severe morbidity, mortality, underlying risk factors and causative pathogens for 192 countries.J Glob Health. 2013; 3: 010401Crossref Google Scholar these estimates show that, despite an effective vaccination programme addressing the two major causes of pneumonia death, pneumonia continues to be a major burden on health services in this South African population. Worldwide, it remains a major cause of care-seeking for child illness, attendance at clinics, admission to hospital, and prescription of antibiotics. This study suggests that the modelled annual incidence estimates for South Africa in 2010, using a risk factor model that included HIV, of 0·22 episodes in children aged younger than 5 years, are broadly consistent with estimates reported in Theodoratou and colleagues' study.6Theodoratou E McAllister DA Reed C et al.Global, regional, and national estimates of pneumonia burden in HIV-infected children in 2010: a meta-analysis and modelling study.Lancet Infect Dis. 2014; 14: 1250-1258Summary Full Text Full Text PDF PubMed Scopus (47) Google Scholar This finding would equate to 1·12 million new cases in South Africa each year in this age group. Although pneumococci and H influenzae type b are major causes of child death from pneumonia, they account for a small proportion of overall pneumonia episodes7Theodoratou E Johnson S Jhass A et al.The effect of Haemophilus influenzae type b and pneumococcal conjugate vaccines on childhood pneumonia incidence, severe morbidity and mortality.Int J Epidemiol. 2010; 39: i172-i185Crossref PubMed Scopus (78) Google Scholar and hence, as Zar and colleagues4le Roux DM Myer L Nicol MP Zar HJ Incidence and severity of childhood pneumonia in the first year of life in a South African birth cohort: the Drakenstein Child Health Study.Lancet Glob Health. 2015; 3: 95-103Summary Full Text Full Text PDF Scopus (87) Google Scholar point out, continuing investment in social determinants of pneumonia and scaling up of the coverage of other known effective interventions2Bhutta ZA Das JK Walker N et al.for the Lancet Diarrhoea and Pneumonia Interventions Study GroupInterventions to address deaths from childhood pneumonia and diarrhoea equitably: what works and at what cost?.Lancet. 2013; 381: 1417-1429Summary Full Text Full Text PDF PubMed Scopus (345) Google Scholar is needed. This investment should also give priority to cross-sectoral approaches, with action on determinants such as maternal education, with appropriate attention given to address the problems of minority and disadvantaged populations. Investment in innovation to tackle other important causes of the remaining pneumonia burden, such as respiratory syncytial virus and influenza,8Nair H Nokes DJ Gessner BD et al.Global burden of acute lower respiratory infections due to respiratory syncytial virus in young children: a systematic review and meta--analysis.Lancet. 2010; 375: 1545-1555Summary Full Text Full Text PDF PubMed Scopus (2001) Google Scholar, 9Nair H Brooks WA Katz M et al.Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis.Lancet. 2011; 378: 1917-1930Summary Full Text Full Text PDF PubMed Scopus (664) Google Scholar is also needed. The study also points out some other important aspects of the pneumonia burden. Increasingly, the major pneumonia burden is in the first 2 years of life (rather than the international focus on children aged younger than 5 years).10Walker CL Rudan I Liu L et al.Global burden of childhood pneumonia and diarrhoea.Lancet. 2013; 381: 1405-1416Summary Full Text Full Text PDF PubMed Scopus (1485) Google Scholar Additionally, severe pneumonia accounting for most pneumonia deaths occurs in the first 6 months of life (in this study 26 of 32 of severe episodes had occurred by age 2 months), which might need increasing attention in programme-priority setting. As part of an epidemiological transition accompanying the trends reported here, wheeze is an increasingly important presentation in children presenting with cough and difficulty breathing (reported in 65% of cases in this study), which merits further research to reduce antibiotic over-treatment and promote correct treatment of wheeze in these children. The male to female incidence ratio of 2:1 is substantially larger than the established (slight) increased pneumonia risk due to so-called biological frailty in boys and points to the need to explore possible gender discrimination in care-seeking. Although the study reports an active surveillance system, this system is in fact an active case ascertainment within an essentially passive surveillance system, which could have led to missed cases (when care was not sought) and differential care-seeking by gender. Alarming levels of differential hospital admissions of children with pneumonia by gender have been reported in some LMICs.11Nair H Simões EA Rudan I et al.for the Severe Acute Lower Respiratory Infections Working GroupGlobal and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: a systematic analysis.Lancet. 2013; 381: 1380-1390Summary Full Text Full Text PDF PubMed Scopus (503) Google Scholar If the full effect of effective interventions against childhood pneumonia is to be realised, then gender discrimination in some countries needs to be recognised as a major source of inequity in child health. Reporting of child health data by sex, as in this study, needs to be seen as an essential element of good practice in the reporting of child health data so that attention can be drawn to sex discrimination, where it exists. The study reports the occurrence of several episodes of pneumonia in a high proportion of children (with about 40 of 141 episodes representing repeat episodes; 22 children had two episodes and nine children had three episodes out of 141 pneumonia episodes). More insight could have gained if more information was known about these children. Did they have a greater prevalence of known risk factors, such as malnutrition, low birthweight, lack of exclusive breastfeeding, or HIV exposure, than expected in this population? Targeted monitoring of these children over the subsequent few months might be justifiable. Whether all or most episodes were acute in nature would be interesting to know, as well as whether a substantial proportion were due to chronic infections (with some of the apparent repeated episodes truly representing episodes with a more chronic course). The highly seasonal pattern is consistent with a largely viral cause and has implications for health service and logistical planning to ensure availability of essential health commodities throughout the year. The separate identification of fast breathing in the first day of life as being due to causes other than pneumonia, such as congenital causes, is important, as well as recognition that interventions other than simply antibiotics could be used. High-quality birth cohort studies are expensive and challenging to do and need a well supported research group with a high level of technical capability and expertise. This study is a good example of such a study yielding reliable data that can inform child heath planning, raise important child health policy issues that merit further investigation, and identify important issues for future research. We declare no competing interests. Incidence and severity of childhood pneumonia in the first year of life in a South African birth cohort: the Drakenstein Child Health StudyPneumonia incidence was high in the first year of life, despite a strong immunisation programme including 13-valent pneumococcal conjugate vaccine. Incidence was associated with pneumonia risk factors that are amenable to interventions. Prevention of childhood pneumonia through public health interventions to address these risk factors should be strengthened. Full-Text PDF Open Access