WHO estimates of the causes of death in children.

BACKGROUND: Child survival efforts can be effective only if they are based on accurate information about causes of deaths. Here, we report on a 4-year effort by WHO to improve the accuracy of this information. METHODS: WHO established the external Child Health Epidemiology Reference Group (CHERG) in 2001 to develop estimates of the proportion of deaths in children younger than age 5 years attributable to pneumonia, diarrhoea, malaria, measles, and the major causes of death in the first 28 days of life. Various methods, including single-cause and multi-cause proportionate mortality models, were used. The role of undernutrition as an underlying cause of death was estimated in collaboration with CHERG. FINDINGS: In 2000-03, six causes accounted for 73% of the 10.6 million yearly deaths in children younger than age 5 years: pneumonia (19%), diarrhoea (18%), malaria (8%), neonatal pneumonia or sepsis (10%), preterm delivery (10%), and asphyxia at birth (8%). The four communicable disease categories account for more than half (54%) of all child deaths. The greatest communicable disease killers are similar in all WHO regions with the exception of malaria; 94% of global deaths attributable to this disease occur in the Africa region. Undernutrition is an underlying cause of 53% of all deaths in children younger than age 5 years. INTERPRETATION: Achievement of the millennium development goal of reducing child mortality by two-thirds from the 1990 rate will depend on renewed efforts to prevent and control pneumonia, diarrhoea, and undernutrition in all WHO regions, and malaria in the Africa region. In all regions, deaths in the neonatal period, primarily due to preterm delivery, sepsis or pneumonia, and birth asphyxia should also be addressed. These estimates of the causes of child deaths should be used to guide public-health policies and programmes

The role of postmortem studies in pneumonia etiology research.

The diagnosis of etiology in severe pneumonia remains a challenging area. Postmortem lung tissue potentially increases the sensitivity of investigations for identification of causative pathogens in fatal cases of pneumonia and can confirm antemortem microbiological diagnoses. Tissue sampling allows assessment of histological patterns of disease and ancillary immunohistochemical or molecular diagnostic techniques. It may also enhance the recognition of noninfectious conditions that clinically simulate acute pneumonia. Biobanking of lung tissue or postmortem culture isolates offers opportunities for new pathogen discovery and research into host-pathogen interactions. The Pneumonia Etiology Research for Child Health study proposes a percutaneous needle biopsy approach to obtain postmortem samples, rather than a full open autopsy. This has the advantage of greater acceptability to relatives, but risks greater sampling error. Both approaches may be susceptible to microbiological contamination or pathogen degradation. However, previous autopsy studies have confirmed the value of histological examination in revealing unsuspected pathogens and influencing clinical guidelines for the diagnosis and treatment of future pneumonia cases

Causes of deaths in children younger than 5 years in China in 2008.

BACKGROUND: Previous estimates of the global burden of disease for children have not included much information from China, leading to a large gap in data. We identified the main causes of deaths in neonates (<1 month), postneonatal infants (1-11 months), and children (<5 years) in China using information that was available to the public. METHODS: The Child Health Epidemiology Reference Group in collaboration with colleagues from Peking University systematically searched Chinese databases that were available to the public. Information was obtained from the Chinese Ministry of Health and Bureau of Statistics websites, Chinese National Knowledge Infrastructure database, and Chinese Health Statistics yearbooks for 1990-2008. We also obtained information from 206 high-quality community-based longitudinal studies of different causes of deaths in children (<5 years) that were written in the Chinese language. A statistical model was developed to estimate the total number of deaths in children according to provinces, age groups, and main causes. FINDINGS: During 1990-2008, the mortality rates in neonates, postneonatal infants, and children were reduced by 70% (from 34.0 to 10.2 per 1000 livebirths), 72% (from 53.5 to 14.9 per 1000 livebirths), and 71% (from 64.6 to 18.5 per 1000 livebirths), respectively, meeting the targets set in the Millennium Development Goal 4. The leading causes of deaths in 2008 were pneumonia, birth asphyxia, and preterm birth complications, each accounting for 15-17% of all deaths. Congenital abnormalities and accidents increased in importance during this period, contributing to 11% and 10% of child deaths, respectively. Sudden infant death syndrome contributed to 5% of deaths in children. INTERPRETATION: Publically available Chinese databases contain much important information that has been underused in the estimation of global and regional burden of disease. On the basis of trends, preterm birth complications are expected to become the leading cause of child mortality in China, whereas deaths from congenital abnormalities, accidents, and sudden infant death syndrome are predicted to continue increasing in importance in the long term. FUNDING: Bill & Melinda Gates Foundation

Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000.

BACKGROUND: Information about the distribution of causes of and time trends for child mortality should be periodically updated. We report the latest estimates of causes of child mortality in 2010 with time trends since 2000. METHODS: Updated total numbers of deaths in children aged 0-27 days and 1-59 months were applied to the corresponding country-specific distribution of deaths by cause. We did the following to derive the number of deaths in children aged 1-59 months: we used vital registration data for countries with an adequate vital registration system; we applied a multinomial logistic regression model to vital registration data for low-mortality countries without adequate vital registration; we used a similar multinomial logistic regression with verbal autopsy data for high-mortality countries; for India and China, we developed national models. We aggregated country results to generate regional and global estimates. FINDINGS: Of 7·6 million deaths in children younger than 5 years in 2010, 64·0% (4·879 million) were attributable to infectious causes and 40·3% (3·072 million) occurred in neonates. Preterm birth complications (14·1%; 1·078 million, uncertainty range [UR] 0·916-1·325), intrapartum-related complications (9·4%; 0·717 million, 0·610-0·876), and sepsis or meningitis (5·2%; 0·393 million, 0·252-0·552) were the leading causes of neonatal death. In older children, pneumonia (14·1%; 1·071 million, 0·977-1·176), diarrhoea (9·9%; 0·751 million, 0·538-1·031), and malaria (7·4%; 0·564 million, 0·432-0·709) claimed the most lives. Despite tremendous efforts to identify relevant data, the causes of only 2·7% (0·205 million) of deaths in children younger than 5 years were medically certified in 2010. Between 2000 and 2010, the global burden of deaths in children younger than 5 years decreased by 2 million, of which pneumonia, measles, and diarrhoea contributed the most to the overall reduction (0·451 million [0·339-0·547], 0·363 million [0·283-0·419], and 0·359 million [0·215-0·476], respectively). However, only tetanus, measles, AIDS, and malaria (in Africa) decreased at an annual rate sufficient to attain the Millennium Development Goal 4. INTERPRETATION: Child survival strategies should direct resources toward the leading causes of child mortality, with attention focusing on infectious and neonatal causes. More rapid decreases from 2010-15 will need accelerated reduction for the most common causes of death, notably pneumonia and preterm birth complications. Continued efforts to gather high-quality data and enhance estimation methods are essential for the improvement of future estimates. FUNDING: The Bill & Melinda Gates Foundation

Global, regional, and national causes of child mortality in 2008: a systematic analysis.

BACKGROUND: Up-to-date information on the causes of child deaths is crucial to guide global efforts to improve child survival. We report new estimates for 2008 of the major causes of death in children younger than 5 years. METHODS: We used multicause proportionate mortality models to estimate deaths in neonates aged 0-27 days and children aged 1-59 months, and selected single-cause disease models and analysis of vital registration data when available to estimate causes of child deaths. New data from China and India permitted national data to be used for these countries instead of predictions based on global statistical models, as was done previously. We estimated proportional causes of death for 193 countries, and by application of these proportions to the country-specific mortality rates in children younger than 5 years and birth rates, the numbers of deaths by cause were calculated for countries, regions, and the world. FINDINGS: Of the estimated 8.795 million deaths in children younger than 5 years worldwide in 2008, infectious diseases caused 68% (5.970 million), with the largest percentages due to pneumonia (18%, 1.575 million, uncertainty range [UR] 1.046 million-1.874 million), diarrhoea (15%, 1.336 million, 0.822 million-2.004 million), and malaria (8%, 0.732 million, 0.601 million-0.851 million). 41% (3.575 million) of deaths occurred in neonates, and the most important single causes were preterm birth complications (12%, 1.033 million, UR 0.717 million-1.216 million), birth asphyxia (9%, 0.814 million, 0.563 million-0.997 million), sepsis (6%, 0.521 million, 0.356 million-0.735 million), and pneumonia (4%, 0.386 million, 0.264 million-0.545 million). 49% (4.294 million) of child deaths occurred in five countries: India, Nigeria, Democratic Republic of the Congo, Pakistan, and China. INTERPRETATION: These country-specific estimates of the major causes of child deaths should help to focus national programmes and donor assistance. Achievement of Millennium Development Goal 4, to reduce child mortality by two-thirds, is only possible if the high numbers of deaths are addressed by maternal, newborn, and child health interventions. FUNDING: WHO, UNICEF, and Bill & Melinda Gates Foundation

Pathogen chip for respiratory tract infections.

Determining the viral etiology of respiratory tract infections (RTI) has been limited for the most part to specific primer PCR-based methods due to their increased sensitivity and specificity compared to other methods, such as tissue culture. However, specific primer approaches have limited the ability to fully understand the diversity of infecting pathogens. A pathogen chip system (PathChip), developed at the Genome Institute of Singapore (GIS), using a random-tagged PCR coupled to a chip with over 170,000 probes, has the potential to recognize all known human viral pathogens. We tested 290 nasal wash specimens from Filipino children <2 years of age with respiratory tract infections using culture and 3 PCR methods-EraGen, Luminex, and the GIS PathChip. The PathChip had good diagnostic accuracy, ranging from 85.9% (95% confidence interval [CI], 81.3 to 89.7%) for rhinovirus/enteroviruses to 98.6% (95% CI, 96.5 to 99.6%) for PIV 2, compared to the other methods and additionally identified a number of viruses not detected by these methods