What is the effect of zinc supplementation in the treatment of measles in children?
Measles infection has reduced globally over the last decade but large outbreaks still occur, especially in low-income countries. Zinc is one of the essential micronutrients necessary for the optimal functioning of the immune system. Zinc deficiency is particularly common in children in low- and middle-income countries. It is therefore important to examine the potential role of zinc supplementation in controlling the symptoms of measles infection in children.
We aimed to critically assess the current evidence from published studies on the effect of zinc supplementation for the treatment of measles in children.
We searched for trials published and pending as at June 2014.
We found one small randomised trial (involving 85 children) that compared zinc supplements versus placebo administered to children with measles and pneumonia. The children were given supportive treatment and vitamin A in both groups. The study was conducted in India and funded by the Child Health Foundation, USA, and by the Nestlé Foundation.
The study we found was small and could not therefore provide enough data to tell whether zinc had an effect on mortality when compared with placebo. Although there were no adverse effects reported, there is insufficient evidence to draw any conclusions about the use of zinc supplements to improve measles symptoms in children. More research is needed to clarify this.
Quality of the evidence
Overall, the evidence was of very low quality.
We cannot draw any definite conclusions from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in measles.
Measles is still an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality.
To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles.
We searched CENTRAL (2014, Issue 5), MEDLINE (1946 to June week 3, 2014), EMBASE (1974 to June 2014), CINAHL (1981 to June 2014), LILACS (1982 to June 2014), Web of Science (1985 to June 2014) and BIOSIS Previews (1985 to June 2014). We also searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to identify unpublished and ongoing studies.
Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles.
Two review authors independently assessed the studies for inclusion and extracted data on outcomes, details of the interventions and other study characteristics using a standardised data extraction form. We used the risk ratio (RR) and hazard ratio as measures of effect with 95% confidence intervals (CI). We included only one study and we did not conduct any meta-analysis.
One RCT met our inclusion criteria. The study was conducted in India and included 85 children diagnosed with measles and pneumonia. The trial showed that there was no significant difference in mortality between the two groups (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.01 to 8.14). Also, there was no significant difference in time to absence of fever between the two groups (hazard ratio (HR) 1.08, 95% CI 0.67 to 1.74). No treatment-related side effects were reported in either group. The overall quality of the evidence can be described as very low.