Global and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: a systematic analysis.
BACKGROUND
The annual number of hospital admissions and in-hospital deaths due to severe acute lower respiratory infections (ALRI) in young children worldwide is unknown. We aimed to estimate the incidence of admissions and deaths for such infections in children younger than 5 years in 2010.


METHODS
We estimated the incidence of admissions for severe and very severe ALRI in children younger than 5 years, stratified by age and region, with data from a systematic review of studies published between Jan 1, 1990, and March 31, 2012, and from 28 unpublished population-based studies. We applied these incidence estimates to population estimates for 2010, to calculate the global and regional burden in children admitted with severe ALRI in that year. We estimated in-hospital mortality due to severe and very severe ALRI by combining incidence estimates with case fatality ratios from hospital-based studies.


RESULTS
We identified 89 eligible studies and estimated that in 2010, 11·9 million (95% CI 10·3-13·9 million) episodes of severe and 3·0 million (2·1-4·2 million) episodes of very severe ALRI resulted in hospital admissions in young children worldwide. Incidence was higher in boys than in girls, the sex disparity being greatest in South Asian studies. On the basis of data from 37 hospital studies reporting case fatality ratios for severe ALRI, we estimated that roughly 265,000 (95% CI 160,000-450,000) in-hospital deaths took place in young children, with 99% of these deaths in developing countries. Therefore, the data suggest that although 62% of children with severe ALRI are treated in hospitals, 81% of deaths happen outside hospitals.


CONCLUSIONS
Severe ALRI is a substantial burden on health services worldwide and a major cause of hospital referral and admission in young children. Improved hospital access and reduced inequities, such as those related to sex and rural status, could substantially decrease mortality related to such infection. Community-based management of severe disease could be an important complementary strategy to reduce pneumonia mortality and health inequities.


BACKGROUND
WHO.
Centre for Population Health Sciences, Global Health Academy, The University of Edinburgh, Edinburgh, UK; Public Health Foundation of India, New Delhi, India. Electronic address: harish.nair@ed.ac.uk.
Harish
H
Nair
University of Colorado Denver and Children's Hospital, Denver, CO, USA; The University of Padjadjaran, Bandung, Indonesia.
Eric Af
EA
Simões
Centre for Population Health Sciences, Global Health Academy, The University of Edinburgh, Edinburgh, UK.
Igor
I
Rudan
Agence de Médecine Préventive, Paris, France.
Bradford D
BD
Gessner
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.
Eduardo
E
Azziz-Baumgartner
School of Population Health, The University of Melbourne, VIC, Australia; Social Insurance Fund Management Centre, Jiangsu, China.
Jian Shayne F
JSF
Zhang
Centers for Disease Control and Prevention, Nairobi, Kenya; Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Daniel R
DR
Feikin
Child Survival Theme, The Gambia Unit, Medical Research Council, Banjul, The Gambia.
Grant A
GA
Mackenzie
Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
Jennifer C
JC
Moiïsi
Barcelona Centre for International Health Research (CRESIB), Hospital Clínic/IDIBAPS, Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça, Ministerio de Saúde, Maputo, Mozambique.
Anna
A
Roca
International Emerging Infections Program, Global Disease Detection Regional Centre, Thailand MOPH-US CDC Collaboration, Nonthaburi, Thailand.
Henry C
HC
Baggett
Child Survival Theme, The Gambia Unit, Medical Research Council, Banjul, The Gambia; Health Protection Services Colindale, Health Protection Agency, London, UK.
Syed Ma
SM
Zaman
Arctic Investigations Program, National Center for Emerging and Zoonotic Infectious Diseases, CDC, Anchorage, AK, USA; Alaska Native Tribal Health Consortium, Anchorage, AK, USA.
Rosalyn J
RJ
Singleton
Research Institute for Tropical Medicine, Department of Health, Alabang, Muntinlupa, Philippines.
Marilla G
MG
Lucero
Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Aruna
A
Chandran
Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina.
Angela
A
Gentile
Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, South Africa; School of Public Health and Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
Cheryl
C
Cohen
Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi, India.
Anand
A
Krishnan
Division of Women and Child Health, Aga Khan University, Karachi, Pakistan.
Zulfiqar A
ZA
Bhutta
Instituto de Atención Pediatrica, Universidad de Ciencias Médicas de Centro América, San José, Costa Rica.
Adriano
A
Arguedas
CDC-Central American Region, Guatemala City, Guatemala.
Alexey Wilfrido
AW
Clara
Federal University of Goiás, Goiânia, Brazil.
Ana Lucia
AL
Andrade
East African Community Secretariat, Arusha, Tanzania.
Maurice
M
Ope
National University of Buenos Aires, Buenos Aires, Argentina.
Raúl Oscar
RO
Ruvinsky
Program for Basic Sciences Development, National University/PNUD, Montevideo, Uruguay.
María
M
Hortal
Center for Health Studies, Universidad del Valle de Guatemala, Guatemala.
John P
JP
McCracken
Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, South Africa; Department of Science and Technology, and National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa.
Shabir A
SA
Madhi
University of Liverpool, Liverpool, UK.
Nigel
N
Bruce
Department of Maternal, Neonatal and Child and Adolescent Health, WHO, Geneva, Switzerland.
Shamim A
SA
Qazi
Bill & Melinda Gates Foundation, Seattle, WA, USA.
Saul S
SS
Morris
International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
Shams
S
El Arifeen
WHO, Indonesia Country Office, Jakarta, Indonesia.
Martin W
MW
Weber
Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
J Anthony G
JAG
Scott
International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
W Abdullah
WA
Brooks
Centers for Disease Control and Prevention, Nairobi, Kenya.
Robert F
RF
Breiman
Centre for Population Health Sciences, Global Health Academy, The University of Edinburgh, Edinburgh, UK.
Harry
H
Campbell
D000208:Acute Disease; D002675:Child, Preschool; D005260:Female; D014943:Global Health; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000401:mortality; D008297:Male; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000401:mortality