Two Articles in this week's edition of The Lancet profile new figures from the World Health Organization revealing that potentially vaccine-preventable Streptococcus pneumoniae (11%) and Haemophilus influenzae type b [Hib] (6%) infections together account for 17% of global deaths in children aged 1—59 months. Thus reduction of child mortality, and the attainment of Millennium Development Goal 4*, could be aided by improved prevention, through vaccination, and treatment of pneumococcal and Hib disease. Both studies were funded by the GAVI Alliance and the Vaccine Fund.
The first Article is written by Dr Katherine L O'Brien, Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, USA, and colleagues who make up the World Health Organization Hib and Pneumococcal Global Disease Burden Working Group. Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and sepsis in children worldwide. Effective interventions are available, including the pneumococcal conjugate vaccine and case management strategies.
They estimated pneumococcal pneumonia cases and deaths, and also estimated the pneumococcal burden of meningitis and non-pneumonia, non-meningitis invasive disease using disease incidence and case-fatality data from a systematic literature review. They found that, in 2000 (the last year of complete data and the year before the introduction of pneumococcal vaccine began), about 14•5 million episodes of serious pneumococcal disease were estimated to occur. Pneumococcal disease caused about 826 000 deaths in children aged 1 months, of which 91,000 were in HIV-positive and 735,000 in HIV-negative children. Of the deaths in HIV-negative children, over 61% occurred in ten African and Asian countries**.
The authors say: "Prevention of pneumococcal disease and death is achievable only if efforts to deliver and implement prevention in regions with the greatest burden of disease are successful. By August, 2008, 24 high-income and two middle-income countries had initiated routine pneumococcal conjugate vaccination, but none in Africa or Asia, which have the highest numbers of pneumococcal deaths and cases. These 26 countries accounted for less than 0•2% of global childhood pneumococcal deaths in 2000." They add the risk of childhood pneumococcal death was 40 times higher in countries not yet using the vaccine compared with those that were.
They conclude: "Our results indicate that large benefits would be achieved by focusing on countries with large populations and moderate incidence, and on selected countries with high incidence and mortality. Pneumococcal deaths in HIV-negative children account for 11% of all mortality in children younger than 5 years. Prevention of pneumococcal disease will greatly accelerate progress towards Millennium Development Goal 4."
In the second Article, Dr James P Watt, also of Johns Hopkins Department of International Health, Baltimore, USA and the WHO working group, investigated deaths due to Haemophillus influenzae type b (Hib)—which is a leading cause of childhood bacterial meningitis, pneumonia, and other serious conditions. They found that Hib caused about 8•13 million serious illnesses worldwide in 2000, and estimated that Hib caused 371,000 deaths in children aged 1-59 months, of which 8100 were in HIV-positive and 363,000 in HIV-negative children.
The authors say: "Hib vaccines are increasingly available, prices are declining, and vaccine financing through the GAVI Alliance is available for low-income countries.Doubts might remain about the true burden of Hib disease, especially in parts of Asia, but their importance decreases as vaccine availability increases and prices fall. Studies in developing countries that have introduced Hib vaccine with GAVI support should help resolve many issues regarding disease burden and vaccine effect."
They conclude: "Global burden of Hib disease is substantial and almost entirely vaccine preventable. Expanded use of Hib vaccine could reduce childhood pneumonia and meningitis, and decrease child mortality."
In an accompanying Comment, Dr Igor Rudan, University of Split, Croatia, and Dr Harry Campbell, The University of Edinburgh Medical School, UK, says: "Effective pneumococcal and Hib vaccines exist and can be effectively integrated into national immunisation programmes. These new estimates suggest that achieving high coverage with these vaccines could prevent a substantial proportion of child mortality globally."
For Dr Katherine L O'Brien and Dr James P Watt, Johns Hopkins Bloomberg School of Public Health, , Department of International Health, Baltimore, USA, please contact Julie Buss T) +1-410-340-9784 E) jbuss@jhsph.edu or Traci Siegel T) +1 202-262-7938 E) traci.siegel@gmmb.com
Dr Igor Rudan, University of Split, Croatia. T) +385-21-489-305 E) irudan@hotmail.com
For both Articles and Comment, see: http://press.thelancet.com/childpneum.pdf
Notes to editors: *MDG 4=reducing childhood mortality by two thirds of the levels in 1990 by 2015
**ten countries: India, China, Bangladesh, Pakistan, Nigeria, Uganda, Ethiopia, Democratic Republic of The Congo, Angola, Afghanistan
Journal
The Lancet