Indian Journal of Community Medicine

EDITORIAL COMMENTARY
Year
: 2014  |  Volume : 39  |  Issue : 4  |  Page : 191--193

Zinc: An effective but neglected child survival intervention


Davendra Kumar Taneja, Akash Malik 
 Department of Community Medicine, Maulana Azad Medical College, New Delhi, India

Correspondence Address:
Dr. Davendra Kumar Taneja
Department of Community Medicine, Maulana Azad Medical College, New Delhi - 110 002
India




How to cite this article:
Taneja DK, Malik A. Zinc: An effective but neglected child survival intervention.Indian J Community Med 2014;39:191-193


How to cite this URL:
Taneja DK, Malik A. Zinc: An effective but neglected child survival intervention. Indian J Community Med [serial online] 2014 [cited 2020 Dec 5 ];39:191-193
Available from: https://www.ijcm.org.in/text.asp?2014/39/4/191/143016


Full Text

 Introduction



Zinc deficiency caused by malnutrition is the 11 th major risk factor in the global distribution of disease burden and is associated with 1.8 million deaths annually. [1]

Mild to moderate zinc deficiency is common in several developing countries, including India, because the commonly consumed staple foods have low zinc contents and are rich in phytates, which inhibit the absorption and utilization of zinc. In a recent study conducted in Delhi, India among children of 6-35 months of age, it was found that the prevalence of zinc deficiency was 73.3% for values less than 70 μg/dl (10.4 μmoles/L) and 33.8% for values less than 60 μg/dl (9 μmoles/L). [2]

Zinc is required for multiple cellular tasks, and especially the immune system depends on a sufficient availability of this essential trace element. Since there are no major body storage depots for zinc, severe deficiency is produced easily and quickly, which can impair a variety of immune functions and host defensive mechanisms. [3]

Strong evidence for a causal relationship between zinc deficiency and childhood infections has come from randomized controlled trials of zinc supplementation in poor but not severely malnourished children in several developing countries. [4],[5],[6] These trials have demonstrated that zinc supplementation during diarrhea not only reduces the duration and severity of diarrhea but it also substantially reduces the incidence of diarrhea and acute respiratory infections in the following months. Apart from its effect on infectious diseases, zinc supplementation increases linear growth and weight gain in growth-retarded children. [7],[8]

India accounts for 1.5 million deaths of children less than 5 years of age. [9] Two major causes, i.e., pneumonia and diarrhea account for 36.9% of the under five deaths. Preventive zinc supplementation alone can prevent nearly 5% [10] or 75,000 child deaths in India each year.

Use of Zinc in India

The Government of India in 2006 issued guidelines for zinc supplementation along with ORS for managing diarrhea in children aged 2 months to 5 years. [11] However, even after 8 years since these guidelines were issued, use of zinc remains abysmally low in most of the states. A survey of 10 districts showed that only 38% of children with diarrhea were given ORS and 1.3% was prescribed zinc. [12] This is attributed to non-availability of dispersible zinc sulfate tablets [13],[14] and lack of awareness of role of zinc in diarrhea among healthcare providers and their prescribing practices. Prescribing practices are a major issue in management of diarrhea; this is evident from the fact that only 47% children who accessed care outside their home were prescribed ORS, which has been in the national program for about four decades. It is also true that about one-fourth of the mothers do not seek care outside their homes for their children in case the child has diarrhea. [12]

Thus, the available evidence indicates that with the policy of zinc sulfate administration during diarrhea, its usage rate is not expected to be high.

 Utility of Prophylactic Zinc Supplementation



Prophylactic zinc and diarrhea

A meta-analysis of RCTs in 1999 established preventive effect of zinc supplementation on diarrhea and pneumonia. The point estimates of the effects in the short-course trials were not significantly different from those in the continuous supplementation trials. However, zinc prophylaxis had no significant effect on children less than one year of age. [15]

Another meta-analysis in 2006 showed significant reduction in episodes of diarrhea as well as severe diarrhea or dysentery. The meta-analysis however included only studies in which zinc prophylaxis was provided for 4 or more months. [16]

A meta-analysis published in 2009 by International Zinc Nutrition Consultative Group, based on 24 studies, showed a 20% lower incidence of diarrhea among children who received zinc supplementation. The effect was independent of duration of zinc prophylaxis. However, beneficial effect of zinc supplements on diarrhea incidence was limited to studies of children with a mean initial age greater than 12 months. [17]

Prophylactic zinc and acute respiratory tract infections

Although some individual studies do not show any beneficial effect of zinc supplementation on ARIs but meta-analysis since 1999 have consistently showed reduction in ALRI/pneumonia. A meta-analysis of RCTs in 1999 established that short course as well as continuous zinc supplementation was effective in reduction of incidence of pneumonia. [15] Another meta-analysis in 2006 included only those studies wherein zinc was given for at least 3 months or more. This study showed that the children receiving preventive zinc supplementation had a fewer attacks of acute respiratory tract infections (ARI) and pneumonia, and fewer days with all ARI. [16] Similarly, a meta-analysis published in 2009 by International Zinc Nutrition Consultative Group on the effect of preventive zinc intervention showed a significant 15% reduction in ALRI. [17]

In a meta-analysis done in 2009, 10 trials were included. These trials were performed on children less than 5 years of age receiving daily/weekly zinc supplementation for greater than 3 months. Analysis showed that zinc reduced the incidence of ALRIs. [18]

A latest meta-analysis published in 2011 by Yakoob et al., based on 18 Randomized Controlled Trials wherein prophylactic zinc was given for at least 3 months or more to children less than 5 years of age, found that zinc supplementation was associated with a statistically significant reduction in incidence of pneumonia. It also showed 9 per cent reduction in all cause mortality. [19]

 Prophylactic Zinc and Growth



Although many individual studies fail to show any significant effect of zinc administration on growth, a meta-analysis published in 2009 by International Zinc Nutrition Consultative Group showed significant increase in height and weight among children who received zinc supplements. [17]

Most studies conducted so far have shown beneficial effects zinc therapy/prophylaxis on reduction of diarrhea or pneumonia or improved growth for 2-3 months following administration of zinc. A recent study has shown effect of short-course zinc prophylaxis in reducing incidence and duration of diarrhea for 5 months post intervention. [20]

With Available Evidence, what can be an Effective Solution?

The fact that utilization of therapeutic zinc remains very low, calls for a community based strategy wherein zinc is made accessible to young children universally as a prophylaxis. This is supported by a recent study conducted in sub-Saharan Africa where preventive zinc supplementation in children of 6-59 months was found to be more cost-effective than therapeutic zinc due to the possibility of high coverage and fewer supplements required. [21]

A valid argument against this type of strategy may be that zinc deficiency cannot be generalized to an entire population of children less than 5 years of age in the country. However, determination of serum zinc levels of the entire population of children less than 5 years of age with desired accuracy is programmatically neither feasible nor cost effective. To identify zinc-deficient populations, WHO has provided a simple indicator, i.e., prevalence of stunting among children less than 5 years of age to be at least 20% or more. [22] According to the National Family Health Survey-3 data, 38.4% of children less than 3 years of age are stunted. [23] This indirectly indicates widespread deficiency of zinc in Indian children and calls for initiation of a nationwide program on zinc prophylaxis for children.

In order to utilize the available resources efficiently, there is need to identify states and districts with high prevalence of stunting among children. Since among children less than 5 years of age, highest morbidity and mortality due to diarrhea and pneumonia occurs in children less than 2 years of age, focusing this age group for zinc prophylaxis is likely to have maximum impact. Based on available evidence and operational considerations zinc prophylaxis can be given in dose of 20 mg elemental zinc daily for two weeks, every 6 months, beginning at 6 months of age, the age at which high risk of diarrhea starts. The existing network of field level workers such as Anganwadis, supported by ASHA, and other volunteers can be effectively utilized to ensure maximum coverage of this intervention. Health system will have to provide necessary support in the form of training and regular supply. Since zinc in the given doses has high margin of safety even if repeated courses are given, [24] dispersible zinc sulfate tablets/syrup should be permitted to be available at all grocery/general stores by bringing it out of the ambit of drug licensing to further increase its availability in every nook and corner of the country. In such a scenario, pharmaceutical companies are likely to promote it as a preventive remedy to increase its sale. This will supplement government educational efforts and enhance awareness among people about benefits of zinc prophylaxis, resulting in increased utilization. These measures will ensure reach of this simple and cost-effective intervention to the targeted children, resulting in a major dent in morbidity and mortality among children less than 5 years of age and thus contribute in a major way to realize the MDG 4 goals for India.

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