The number of deaths in children due to lower respiratory infections (LRIs) such as pneumonia and influenza has come down considerably. Yet, they still account for the highest number of deaths in children under 5 years of age, at one in seven of all deaths in this age group, according to a detailed study published in the journal The Lancet Infectious Diseases.
The conclusion is that there is no "one size fits all" solution to reduce child mortality significantly from LRIs in every country” according to researcher Bobby Reiner. The biggest players in this reduction appear to be increased vaccination coverage against Hemophilus influenza type b (Hib) and pneumococcus, as well as less household air pollution, all of which together brought down deaths by about 12% by themselves.
Comprehensive health planning is necessary, therefore, to make sure each country gives its children the means to resist and survive LRI exposure, on a holistic basis. This could include measures ranging from universal immunization and more breastfeeding to preventing exposure to air pollution and excessive antibiotic use.
Haemophilus influenzae bacteria, 3D illustration - Illustration Credit: Kateryna Kon / Shutterstock
Changes in mortality patterns
The study is focused on the annual Global Burden of Disease (GBD), which tells us how LRI mortality and risk varies across 195 countries and nations. LRI may occur as a result of influenza, pneumonia, Hib, and other respiratory viruses.
The number of child deaths due to LRI shows a 65% fall in over almost 3 decades, from 1990 to 2017. In other words, from 2.3 million child deaths, it came down to about 810,000, respectively, out of the grim total of. In terms of the mortality rate, it was 363/100,000 in 1990, coming down by 67% to 119/100,000 in 2017.
Though this reduction is welcome, LRIs still account for a large chunk of the 5.4 million deaths in children below 5 years in 2017 – about 15%, down from 20% of deaths in 1990. In Uzbekistan, however, 40% of child deaths are due to LRI – the highest proportion in the world.
The most affected countries were India, Pakistan and Nigeria – with over 185,000, 153,000, and 40,000 respectively. The pace of control is thus less than that for many other infectious diseases affecting children such as tetanus and measles. Another aspect of this condition is that the incidence of LRI is falling more slowly than the death rate. In other words, it is more difficult to prevent LRI than it is to prevent death once it is acquired by a child.
At present, the highest child mortality in the world is in South Sudan, at about 530 deaths/100,000. And in 2017, Africa witnessed over half of all such deaths, at over 430,000.
In countries like China and Turkey, the Healthcare Access and Quality (HAQ) Index has shot up, which indicates a dramatic reduction in death due to preventable mortality. The authors feel that this rapid improvement in healthcare systems in these countries could be a prime cause for the steep fall in LRI deaths. Turkey, for instance, saw a fall of over 96%.
The largest numerical decline in child death due to LRI was in Niger, where it fell to less than 25% of the original. This is more remarkable when we remember that this country had the highest rate in the whole world, at about 1,350 per 100,000 children, in 1990, but is now at 330.
In the population overall, the percentage of people who died as a result of LRIs came down from 2% to 1% in the years between 1990 and 2017. However, the average of 1% is far from the reality in many countries, such as Nigeria, where the real incidence is almost 6%, compared to Saudi Arabia where it is only 0.1%.
The local picture
To find out which were the worst locations for LRIs, the researchers published a second study looking at 52 countries in Africa alone, with much more detail, to the level of individual districts. This is part of the Local Disease Burden (LBD) project, published in Nature Microbiology on September 30. It helps administrators to easily find which districts have shown progress in LRI mortality, and which lag behind.
In fact, though LRI mortality declined overall by almost 30% since 2000, there was a large area at high risk, extending over the following countries: Central African Republic, South Sudan, Chad, Niger, Cameroon, the Democratic Republic of the Congo, and Nigeria. In 2017, almost a third of LRI deaths was traced to these 8 countries. In other words, 31% of all deaths came from a region containing only 13% of the child population in Africa.
Earlier, Somalia and Kenya were among the African countries with the highest child LRI deaths, but 2017 saw a dramatic reduction in this risk. The greatest decline in any country was in Angola, and in any division it was in the Blue Nile state of Sudan, where the 2000 figures of 419 LRI episodes per 1000 children went down to 222 in 2017. On the other hand, South Sudan, as mentioned earlier, is showing a rise in LRI mortality, and the highest death rate following pneumococcal pneumonia, in contrast to the worldwide tendency towards reduced child LRI deaths. Pneumococcal vaccines could be a potent tool in reducing this high mortality, as shown in the few countries where it is already offered.
Africa saw almost 24 million LRI episodes in 2017, which means 122 /1,000 children. The following African countries showed wide risk variations between districts: Nigeria, Somalia, Ethiopia and Senegal. For instance, Yobe State in Nigeria had 148 episodes/1,000 but Anambra in the same country had only 32.
The current figures are, however, far from the target of 3/1,000 or less by 2025, set by the Global Action Plan for the Prevention and Control of Pneumonia and Diarrhea (GAPPD). Uniform progress in 41 countries seems to indicate they will accomplish the target, but in 11 countries one or more divisions will be way off target by 2025. The authors point out that risk prevention by means such as proper handwashing, less household air pollution, pneumococcal vaccination, and Hib vaccination, could have prevented 65% of these deaths.
They are now trying to expand the area of precision mapping to include many other poorer countries, thus helping to target those areas with the maximum potential for intervention.
Comments Simon I. Hay, senior author, “Lower respiratory infections remain pernicious and preventable causes of premature death. Accelerating their decline is essential for nations seeking to meet the UN's Sustainable Development Goal for under-5 childhood mortality.”
- GBD 2017 Lower Respiratory Infections Collaborators. Quantifying risks and interventions that have affected the burden of lower respiratory infections among children younger than 5 years: an analysis for the Global Burden of Disease Study 2017. The Lancet Infectious Diseases. October 30, 2019, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(19)30410-4/fulltext
- Reiner, R.C., Welgan, C.A., Casey, D.C. et al. Identifying residual hotspots and mapping lower respiratory infection morbidity and mortality in African children from 2000 to 2017. Nature Microbiology (2019) doi:10.1038/s41564-019-0562-y. https://www.nature.com/articles/s41564-019-0562-y