Photo of Dr Jane Barker with children in PNG for article on Pneumonia - the most lethal killer of children

Pneumonia: the most lethal killer of children

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Does medicine come with global responsibility? I believe that, at the very least, we should be willing to speak out against inequities in medical care, such as childhood deaths from pneumonia.

A report recently published by Save the Children – Fighting for breath – is a call to action against childhood pneumonia, which has been identified as the single major cause of childhood mortality and described as a global epidemic.

Pneumonia kills almost a million children each year. This has been estimated to be two fatalities every minute of every day, more than gastroenteritis, malaria and measles combined. Eighty percent of these children are under 2 years old.

In a Lancet editorial responding to the Save the Children report, the author suggests that the cause lies in neglect, that pneumonia, despite its frequency, has been a “forgotten disease”.

While pneumonia is one of the commonest causes of childhood hospital admission in Western nations, with early identification and effective treatment, the mortality is low, and hence it is not considered a killing disease. However, childhood pneumonia is more frequent when there is poverty, overcrowding and malnutrition, and mortality is higher where there is no, or poor, access to effective medical treatment. A systematic review of 39 countries found that low socio-economic status among children was associated with a 62% increase in pneumonia mortality. This is shown here at home, where there are higher levels of hospitalisation for pneumonia among Indigenous children than non-Indigenous children.

This is a disease that is preventable, easily diagnosed clinically, and treatable at low cost if diagnosed early.

In the foreword of Fighting for breath, Kofi Annan quoted Martin Luther King:

“We are confronted with the fierce urgency of now … there is such a thing as being too late. This is no time for apathy or complacency. This is a time for vigorous and positive action.”

He asks that policy makers be seized by “the fierce urgency of now”. Indeed, it is appalling that children are dying in their thousands across the world when we have the ability to prevent and treat pneumonia.

The Lancet editorial suggests that the Sustainable Development Goal to eliminate preventable child deaths by 2030 will remain just an aspiration unless childhood pneumonia is vigorously addressed.

Working with children in Papua New Guinea

As a young doctor, I was privileged to work in the highlands of Papua New Guinea. In Goroka, there was an impressive and dedicated research team at the PNG Institute of Medical Research, led at the time by Dr Michael Alpers. As a clinician, I was always impressed that research emphasis was put on the most commonly presenting diseases, and pneumonia was one of those.

On the paediatric ward where I worked, a majority of the admissions were for infectious diseases, primarily pneumonia and meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae.

Statistics are merely numbers, but they represent loved children such as those I treated, babies fighting for breath. There were no cots in the ward, the babies slept with their mothers, who stayed with them around the clock, sometimes for weeks at a time.

While a majority of those children with pneumonia survived with antibiotic therapy, many with a more severe disease, co-morbid malnutrition or other infections such as meningitis, did not survive.

The research institute at the time was running trials in two highland communities of the polyvalent pneumococcal vaccine first trialled in South African mineworkers. Their research, which showed the efficacy of the vaccine in children aged 6 months and over, was first published in 1986. We know now that the vaccine does not offer lifelong immunity but protects the children in the years when they are most vulnerable.

For me as a clinician working in a ward with dozens of children with pneumonia, this vaccine was very welcome and seemed like a wonderful solution to an otherwise overwhelming problem. In fact, because of the high cost, pneumococcal vaccine was not universally introduced in PNG until 2014, funded through Gavi, the Vaccine Alliance. This conjugate vaccine covers 13 serotypes, unlike the vaccine used in the PNG trials which covered 23 serotypes, but it is effective from a very young age.

I remember in the early 1980s attending a lecture at the Papua New Guinea Institute of Medical Research about the newly identified immune deficiency syndrome, the early days of HIV in the United States. What occurred over the following decade was, in scientific terms, very impressive – the retrovirus was identified, effective treatment was developed, and extensive public health campaigns were run. At least in Western countries, HIV was contained. Had this not happened, HIV may have spread, as it continued to do in sub-Saharan Africa, until treatment was made available.

Pneumonia is a disease older than medical science

In contrast, pneumonia is a disease older than medical science. We have had antibiotic treatment since Alexander Fleming and his petri dish in 1928. Penicillin was made clinically available in the 1940s. We have had an effective vaccine for 25 years. In Australia, the 7-valent pneumococcal vaccine was introduced for Aboriginal children in 2001. Yet, across the globe, nearly a million children are dying from pneumonia annually and 170 million children who would benefit from it remain unimmunised. Indeed, there is such a thing as being too late – at least 13 years too late for the many children who were not vaccinated and who died from pneumonia.

The prevention of pneumonia deaths lies not only in immunisation but in dealing with the social determinants of health, effective and accessible health care delivery and a global sense of responsibility to achieve this. A 3–5-day course of antibiotics can cost as little as 40 cents per dose, so cost of treatment is not a barrier.

However, in Australia, the pneumococcal conjugate vaccine (PCV13) costs $125–$150 per dose to buy over the counter. At least two doses are recommended, preferably three. Pneumococcal conjugate vaccines are the most expensive vaccines supplied by Gavi. Thankfully, the two companies that produce the vaccine have lowered the price for the 69 countries supported by Gavi to $9.15 per dose. While this is still expensive considering the numbers involved, it has meant that, assuming appropriate health care delivery, the poorest children may be immunised. For those middle-income countries where there are proportions of the population who live in poverty, covering all children may not be possible. Transparency in the real cost of manufacturing these vaccines would greatly assist in the global action against pneumonia.

A 2017 study from Papua New Guinea reviewed hospital admissions for pneumonia and meningitis in the era of conjugate vaccines but before there were high levels of coverage. S. pneumoniae and H. influenzae remain the major bacteria isolated. H. influenzae type B conjugate vaccine had been introduced in 2008 and, over the period of the study, coverage increased to just under 50% in the children studied. Although pneumococcal vaccine was introduced in 2014, by 2015 three-dose coverage of PCV13 was very low, at below 7%.

These results put the emphasis on the need for effective health care systems for vaccine delivery. This study forms a baseline for what will be of real interest: the effect on children’s admissions when higher levels of immunisation are reached.

Thirty years on from my time in PNG, I feel excited about this increased coverage and wonder whether we can dream of seeing what we saw when another vaccine was introduced in PNG.

When I first worked in the highlands, we would regularly see children admitted with a disease called “pigbel” in New Guinea pidgin. It was a devastating disease occurring in older children, precious because they had survived their infancy. A necrotising enterocolitis caused by Clostridium perfringens, it was associated with protein deprivation, poor hygiene, traditional pig feasts and staple diets containing antitrypsin inhibitors. It led to small bowel strangulation and ischaemia. A vaccine was introduced, which had originally, curiously, been developed for piglets. The effect was dramatic. By the end of my stay we saw no more pigbel and I understand that, recently, the vaccine has been removed from the vaccine schedule.

Pneumococcal vaccine is more complex because of the multiple and varying serotypes (>90 different serotypes have been identified) occurring in different communities, so we may never see what seemed like a miracle – the virtual eradication of a disease through immunisation and changes in living conditions. But we may hope to see a significant reduction in mortality from pneumonia. There is ongoing concern of “replacement disease”, an increase in the carriage of serotypes not included in the vaccine, leading to infection caused by these non-vaccine serotypes.

Pneumonia is a disease of poverty

Inequality remains at the heart of the causes of childhood pneumonia. Pneumonia is a disease of poverty. It is disturbing that in this high technology era of modern medicine, there remain populations where children are dying from preventable and treatable diseases. The vaccines that we use to protect our own children have often been trialled in low income countries and those same populations may not be benefitting from this research. While conjugate vaccines are expensive to develop, we need to investigate ways of producing them at a cost that is not prohibitive for poorer countries.

Above all, we need to take a global responsibility for children and we need, somewhat belatedly, to be seized by “the fierce urgency of now”.

“We have the knowledge, financial resources, and tools to save lives. What we are lacking is a powerful coalition to lead the drive against pneumonia.”
Kofi Annan

This article was originally published in MJA Insight on 12 February 2018

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