WHAT'S NEW THIS SUNDAY: THREE ON PNEUMONIA AND DIARRHEA

Friday, 15th of June 2012

• PNEUMONIA AND DIARRHOEA: TACKLING THE DEADLIEST DISEASES FOR THE WORLD’S POOREST CHILDREN

Since these two diseases account for an estimated 29 percent of under-five mortality, a concerted attack on both is necessary to achieve MDG 4, as set forth in this major UNICEF report.

Below, excerpts from the Executive Summary. The summary and full report are best viewed at http://www.unicef.org/media/files/UNICEF_P_D_complete_0604.pdf

This report makes a remarkable and compelling argument for tackling two of the leading killers of children under age 5: pneumonia and diarrhoea.

By 2015 more than 2 million child deaths could be averted if national coverage of cost effective interventions for pneumonia and diarrhoea were raised to the level of the richest 20 per cent in the highest mortality countries. This is an achievable goal for many countries as they work towards more ambitious targets such as universal coverage.

Pneumonia and diarrhoea are leading killers of the world’s youngest children, accounting for 29 per cent of deaths among children under age 5 worldwide – or more than 2 million lives lost each year (figure 1). This toll is highly concentrated in the poorest regions and countries and among the most disadvantaged children within these societies. Nearly 90 per cent of deaths due to pneumonia and diarrhoea occur in sub-Saharan Africa and South Asia.

The concentration of deaths due to pneumonia and diarrhoea among the poorest children reflects a broader trend of uneven progress in reducing child mortality. Far fewer children are dying today than 20 years ago – compare 12 million child deaths in 1990 with 7.6 million in 2010, thanks mostly to rapid expansion of basic public health and nutrition interventions, such as immunization, breastfeeding and safe drinking water.

But coverage of low-cost curative interventions against pneumonia and diarrhoea remains low, particularly among the most vulnerable. There is a tremendous opportunity to narrow the child survival gap between the poorest and better-off children both across and within countries – and to accelerate progress towards the Millennium Development Goals – by increasing in a concerted way commitment to, attention on and funding for these leading causes of death that disproportionately affect the most vulnerable children.

We know what needs to be done

Pneumonia and diarrhoea have long been regarded as diseases of poverty and are closely associated with factors such as poor home environments, undernutrition and lack of access to essential services. Deaths due to these diseases are largely preventable through optimal breastfeeding practices and adequate nutrition, vaccinations, hand washing with soap, safe drinking water and basic sanitation, among other measures. Once a child gets sick, death is avoidable through cost-effective and life-saving treatment such as antibiotics for bacterial pneumonia and solutions made of oral rehydration salts for diarrhoea. An integrated approach

to tackle these two killers is essential, as many interventions for pneumonia and diarrhoea are identical and could save countless children’s lives when delivered in a coordinated manner (figure 2).

An equity approach could save more than 2 million children’s lives by 2015

The potential for saving lives by more equitably scaling up the proper interventions is large. Modelled estimates suggest that by 2015 more than 2 million child deaths due to pneumonia and diarrhoea could be averted across the 75 countries with the highest mortality burden if national coverage of key pneumonia and diarrhoea interventions were raised to the level in the richest 20 per cent of households in each country. In this scenario child deaths due to pneumonia in these countries could fall 30 per cent, and child deaths due to diarrhoea could fall 60 per cent (figure 3). Indeed, all-cause child mortality could be reduced roughly 13 per cent across these 75 countries by 2015.

Reaching the most vulnerable children, who are often at the greatest risk of pneumonia and diarrhoea, through routine immunization programmes remains a challenge but is essential to realize the full potential of both new and old vaccines alike.

Infant feeding

Exclusive breastfeeding during the first six months of life is one of the most cost-effective child survival interventions and greatly reduces the risk of a young infant dying due to pneumonia or diarrhoea (figure 6). Exclusive breastfeeding rates have increased markedly in many high-mortality countries since 1990.

Despite this progress, fewer than 40 per cent of children under 6 months of age in developing countries are exclusively breastfed. Optimal breastfeeding practices are vital to reducing morbidity and mortality due to pneumonia and diarrhoea.

Water and sanitation

The Millennium Development Goal target on use of an improved drinking water source has been met globally as of 2010; a stunning success. Yet 783 million people still do not use an improved drinking water source, and 2.5 billion do not use an improved sanitation facility, mostly in the poorest households and rural areas; 90 per cent of people who practice open defecation, the riskiest sanitation practice, live in rural areas (figure 7). Nearly 90 per cent of deaths due to diarrhoea worldwide have been attributed to unsafe water, inadequate sanitation and poor hygiene. Hand washing with water and soap, in particular, is among the most cost-effective health interventions to reduce the incidence of both childhood pneumonia and diarrhoea.

Treatment for suspected pneumonia

Timely recognition of key pneumonia symptoms by caregivers followed by seeking appropriate care and antibiotic treatment for bacterial pneumonia is lifesaving. Careseeking for children with symptoms of pneumonia has increased slightly in developing countries, from 54 per cent around 2000 to 60 per cent around 2010.

Sub-Saharan Africa saw about a 30 per cent rise over this period, driven largely by gains among the rural population (figure 8). Yet appropriate careseeking for suspected childhood pneumonia remains too low across developing countries, and less than a third of children with suspected pneumonia receive antibiotics. The poorest children in the poorest countries are least likely to receive treatment when sick.

Treatment for diarrhoea

Children with diarrhoea are at risk of dying due to dehydration, and early and appropriate fluid replacement is a main intervention to prevent death. Yet few children with diarrhoea in developing countries receive appropriate treatment with oral rehydration therapy and continued feeding (39 per cent). Even fewer receive solutions made of oral rehydration salts (ORS) alone (one-third), and the past decade has seen no real progress in improving coverage across developing countries (figure 9). Moreover, the poorest children in the poorest countries are least likely to use ORS, and zinc treatment remains largely unavailable in high-mortality countries. The stagnant low ORS coverage over the past decade indicates a widespread failure to deliver one of the most cost-effective and life-saving child survival interventions and underscores the urgent need to refocus attention and funding on diarrhoea control.

• PREVENTIVE ZINC SUPPLEMENTATION

BMC Public Health. 2011; 11(Suppl 3): S23.

Preventive zinc supplementation in developing countries: impact on mortality and morbidity due to diarrhea, pneumonia and malaria

Background

Zinc deficiency is commonly prevalent in children in developing countries and plays a role in decreased immunity and increased risk of infection. Preventive zinc supplementation in healthy children can reduce mortality due to common causes like diarrhea, pneumonia and malaria. The main objective was to determine all-cause mortality and cause-specific mortality and morbidity in children under five in developing countries for preventive zinc supplementation.

Data sources/ review methods

A literature search was carried out on PubMed, the Cochrane Library and the WHO regional databases to identify RCTs on zinc supplementation for greater than 3 months in children less than 5 years of age in developing countries and its effect on mortality was analyzed.

Results

The effect of preventive zinc supplementation on mortality was given in eight trials, while cause specific mortality data was given in five of these eight trials. Zinc supplementation alone was associated with a statistically insignificant 9% (RR = 0.91; 95% CI: 0.82, 1.01) reduction in all cause mortality in the intervention group as compared to controls using a random effect model. The impact on diarrhea-specific mortality of zinc alone was a non-significant 18% reduction (RR = 0.82; 95% CI: 0.64, 1.05) and 15% for pneumonia-specific mortality (RR = 0.85; 95% CI: 0.65, 1.11). The incidence of diarrhea showed a 13% reduction with preventive zinc supplementation (RR = 0.87; 95% CI: 0.81, 0.94) and a 19% reduction in pneumonia morbidity (RR = 0.81; 95% CI: 0.73, 0.90). Keeping in mind the direction of effect of zinc supplementation in reducing diarrhea and pneumonia related morbidity and mortality; we considered all the outcomes for selection of effectiveness estimate for inclusion in the LiST model. After application of the CHERG rules with consideration to quality of evidence and rule # 6, we used the most conservative estimates as a surrogate for mortality. We, therefore, conclude that zinc supplementation in children is associated with a reduction in diarrhea mortality of 13% and pneumonia mortality of 15% for inclusion in the LiST tool. Preventive zinc supplementation had no effect on malaria specific mortality (RR = 0.90; 95% CI: 0.77, 1.06) or incidence of malaria (RR=0.92; 95 % CI 0.82-1.04)

Conclusion

Zinc supplementation results in reductions in diarrhea and pneumonia mortality.

• ROTAVIRUS VACCINE AND DIARRHEA MORTALITY: QUANTIFYING REGIONAL VARIATION IN EFFECT SIZE

Conclusions

There is strong evidence suggesting that rotavirus vaccine decreases rotavirus specific mortality and thus all diarrhea mortality in all regions of the world. Though the effect size appears to be greater among children living in developed countries as compared to low-income countries, the increased risk of diarrhea mortality is greater in developing countries therefore increasing the justification for the continued promotion of this important child survival tool.

Diarrhea mortality remains a leading cause of child death and rotavirus vaccine an effective tool for preventing severe rotavirus diarrhea. New data suggest vaccine efficacy may vary by region.

Methods

We reviewed published vaccine efficacy trials to estimate a regional-specific effect of vaccine efficacy on severe rotavirus diarrhea and hospitalizations. We assessed the quality of evidence using a standard protocol and conducted meta-analyses where more than 1 data point was available.

Results

Rotavirus vaccine prevented severe rotavirus episodes in all regions; 81% of episodes in Latin America, 42.7% of episodes in high-mortality Asia, 50% of episodes in sub-Saharan Africa, 88% of episodes low-mortality Asia and North Africa, and 91% of episodes in developed countries. The effect sizes observed for preventing severe rotavirus diarrhea will be used in LiST as the effect size for rotavirus vaccine on rotavirus-specific diarrhea mortality.

Conclusions

Vaccine trials have not measured the effect of vaccine on diarrhea mortality. The overall quality of the evidence and consistency observed across studies suggests that estimating mortality based on a severe morbidity reduction is highly plausible.

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