Zinc and copper supplementation in acute diarrhea in children: a double-blind randomized controlled trial

Potential molecular mechanisms of zinc- and copper-mediated antiviral activity on COVID-19

Novel coronavirus disease 2019 (COVID-19) has spread across the globe; and surprisingly, no potentially protective or therapeutic antiviral molecules are available to treat severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, zinc (Zn) and copper (Cu) have been shown to exert protective effects due to their antioxidant, anti-inflammatory, and antiviral properties. Therefore, it is hypothesized that supplementation with Zn and Cu alone or as an adjuvant may be beneficial with promising efficacy and a favorable safety profile to mitigate symptoms, as well as halt progression of the severe form of SARS-CoV-2 infection. The objective of this review is to discuss the proposed underlying molecular mechanisms and their implications for combating SARS-CoV-2 infection in response to Zn and Cu administration. Several clinical trials have also included the use of Zn as an adjuvant therapy with dietary regimens/antiviral drugs against COVID-19 infection. Overall, this review summarizes that nutritional intervention with Zn and Cu may offer an alternative treatment strategy by eliciting their virucidal effects through several fundamental molecular cascades, such as, modulation of immune responses, redox signaling, autophagy, and obstruction of viral entry and genome replication during SARS-CoV-2 infection.

Efficacy of zinc supplementation in the management of acute diarrhoea: a randomised controlled trial

Background: Zinc has been recommended for the treatment of acute diarrhoea; however, there are heterogeneous reports regarding its efficacy.Aim: This study investigated the efficacy of zinc supplementation on the treatment outcomes of children admitted to hospital with acute diarrhoea.Methods: A double-blind, randomised, placebo-controlled trial was conducted in the Srinakharinwirot University Hospital's Paediatric Department, Thailand. Eligible children were randomly allocated to receive either zinc bisglycinate (15 mg elemental zinc) or a placebo. The study protocol was registered in the Thai Clinical Trials Registry (TCTR20190423004).Results: Of 86 patients, 50 (58.1%) were male and the mean age (range) was 2.5 years (6 months to 9.3 years). The median (IQR) number of hours to recovery from diarrhoea was significantly less in the zinc group than in the controls [44 (24-48) vs 52 (36-80) hours, respectively, p < 0.01]. The median (IQR) number of stools was significantly lower in the zinc group [5 (3-12)] than in the controls [7 (4-17), p = 0.02]. The median (IQR) duration of intravenous fluid therapy was 40 (24-56) hours in the zinc group and 56 (40-73) in the control group (p < 0.01). The duration of hospitalisation was 60 (44-72) hours in the zinc group and 84 (56-136) hours in the controls (p < 0.01). There was good compliance by all participants in both groups.Conclusion: Zinc supplementation can reduce the time to resolution of acute diarrhoea, the length of hospital stay and the frequency of stools. Zinc supplementation is recommended as a routine strategy for Thai children with acute diarrhoea.

The Copper/Zinc Ratio Correlates With Markers of Disease Activity in Patients With Inflammatory Bowel Disease

BACKGROUND

Zinc (Zn) and copper (Cu) are trace elements that serve as cofactors in catalytic processes with impact on immune responses. In patients with inflammatory bowel disease (IBD), decreased levels of serum Zn and Cu have been observed. Here, we investigated the effect of inflammation on serum concentrations of these trace elements in patients with IBD.

METHODS

In this cross-sectional study, 98 patients with Crohn disease (CD) and 56 with ulcerative colitis (UC) were prospectively enrolled. Disease activity parameters, such as C-reactive protein (CRP) and fecal calprotectin (FC) were compared to serum Zn, Cu, and Cu/Zn ratio.

RESULTS

Zinc insufficiency was observed in 11.2% of patients with CD and 14.3% with UC, Cu insufficiency in 20.4% with CD and 7.1% with UC. Anemia, hypoalbuminemia, increased FC, and elevated CRP were more frequently present in Zn-insufficient patients with IBD. In contrast, lower serum CRP values and a trend to lower FC were observed in Cu-insufficient patients. In multiple linear regression models adjusted for age, gender, and serum albumin, CRP positively correlated with serum Cu (P < 0.001) and the Cu/Zn ratio in both CD and UC (P < 0.001) but not with serum Zn concentrations. FC levels correlated only with the Cu/Zn ratio in patients with UC (P < 0.038).

CONCLUSION

Systemic inflammation inversely affected the serum Zn and Cu concentrations and, consequently, resulted in an increased Cu/Zn ratio.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF).

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity.We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoeaThere is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence).In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD -11.46 hours, 95% CI -19.72 to -3.19; 2581 children, 9 trials, low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, 6 trials, moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (MD -26.39 hours, 95% CI -36.54 to -16.23; 419 children, 5 trials, high certainty evidence).Conversely, in children younger than six months of age, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, 2 trials, moderate certainty evidence), or the number of children who still have diarrhoea on day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, 1 trial, moderate certainty evidence).None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children greater than six months of age: RR 1.57, 95% CI 1.32 to 1.86; 2605 children, 6 trials, moderate certainty evidence; children less than six months of age: RR 1.54, 95% CI 1.05 to 2.24; 1334 children, 2 trials, moderate certainty evidence). Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, 5 trials, moderate certainty evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency.

Safety of a Bioactive Polyphenol Dietary Supplement in Pediatric Subjects with Acute Diarrhoea

The hematological and clinical chemistry profile for children aged 6 months to 5 years with acute diarrhoea was measured in a double blind clinical trial. Subjects were randomized to the study group (N = 44) given a bioactive polyphenol dietary supplement in oral rehydration solution (ORS) or to the control group (N = 41) given distilled water as a placebo in ORS twice daily for up to 4 days. All subjects received 10 mg zinc daily for the 4 days in the study. Venous blood was collected for complete blood count, electrolytes, liver function, and creatinine upon enrollment (baseline) and at the end of 4 days (end of study); mean values were compared by 95% confidence intervals. Overall, blood factors measured either remained the same over the 4 days or increased or decreased at the same levels between the two groups during the study period. All values were within accepted ranges for paediatric subjects except serum AST (SGOT), where the mean value of the study group approached the upper bound of the range on day 4 but was comparable to the value of the control group. Consumption of this supplement twice daily for 4 days is safe for children and infants.

Differential estimates of underweight-for-age and growth related morbidity according to different growth standards in Indian children

OBJECTIVE

To compare the four different growth standards currently used in India [WHO (World Health Organization); NCHS (National Center for Health Statistics); ICDS (Integrated Child Development Scheme); IAP (Indian Academy of Pediatrics)] and determine which better predicts growth related morbidity in children after 3 mo of follow-up.

METHODS

The present cohort study was done at Indira Gandhi Government Medical College and Hospital, Nagpur, India. Eligible children were those who had; > 3 unformed stools in the prior 24 h, the duration of their diarrhea was up to 72 h; and they were able to accept oral fluids or feeds. Main outcome measures were classification of the malnutrition status as per each of the four growth standards by weight-for-age and weight-for-height z scores at three months follow-up.

RESULTS

A total of 724 children were included. Mean age was 17.8 mo; 40.6 % were ≤ 12 mo and 59.1 % were males. Estimates of malnourished varied by the four standards, (NCHS, 62.2 % to IAP, 7.4 %). When separated into 'malnourished' and 'severely malnourished' categories, differences were greater, (NCHS, 27.9 % vs. ICDS, 1.9 %). Overall agreement was 'fair' (0.2435, z = 22.21, p = 0.0000). After follow-up, children who were 'severely malnourished' gained more weight than the 'malnourished'group; however, mean weight differed by the four charts [e.g., IAP 767 g (SD ± 611 g), vs. ICDS 884.7 g (SD ± 778 g)].

CONCLUSIONS

Growth standards reported different rates of malnourished categories. The utility of the standards to detect children who are constitutionally vs. pathologically small is questionable. Monitoring the nutritional status of children at both the individual level and at population level has implications for clinical practice, policy development and resource allocation.

Protocol for the economic evaluation of the diarrhea alleviation through zinc and oral rehydration salt therapy at scale through private and public providers in rural Gujarat and Uttar Pradesh, India

BACKGROUND

Child diarrhea persists as a leading public health problem in India despite evidence supporting zinc and low osmolarity oral rehydration salts as effective treatments. Across 2 years in 2010-2013, the Diarrhea Alleviation using Zinc and Oral Rehydration Salts Therapy (DAZT) program was implemented to operationalize delivery of these interventions at scale through private and public sector providers in rural Gujarat and Uttar Pradesh, India.

METHODS/DESIGN

This study evaluates the cost-effectiveness of DAZT program activities relative to status quo conditions existing before the study, comparing a Monte Carlo simulation method with net-benefit regression, discussing the strengths and weaknesses of each approach. A control group was not included in the 'before and after' study design as zinc has proven effectiveness for diarrhea treatment. Costs will be calculated using a societal perspective including program implementation and household out-of-pocket payments for care seeking, as well as estimates of wages lost. Outcomes will be measured in terms of episodes averted in net-benefit regression and in terms of the years of life lost component of disability-adjusted life years in the method based on Monte Carlo simulation. The Lives Saved Tool will be used to model anticipated changes in mortality over time and deaths averted based on incremental changes in coverage of oral rehydration salts and zinc. Data will derive from cross-sectional surveys at the start, midpoint, and endpoint of the program. In addition, Lives Saved Tool (LiST) projections will be used to define the reference case value for the ceiling ratio in terms of natural units.

DISCUSSION

This study will be useful both in its application to an economic evaluation of a public health program in its implementation phase but also in its comparison of two methodological approaches to cost-effectiveness analysis. Both policy recommendations and methodological lessons learned will be discussed, recognizing the limitations in drawing strong policy conclusions due to the uncontrolled study design. It is expected that this protocol will be useful to researchers planning what method to use for the evaluation of similar before and after studies.

Oral zinc supplementation for the treatment of acute diarrhea in children: a systematic review and meta-analysis

Evidence supporting the impact of therapeutic zinc supplementation on the duration and severity of diarrhea among children under five is largely derived from studies conducted in South Asia. China experiences a substantial portion of the global burden of diarrhea, but the impact of zinc treatment among children under five has not been well documented by previously published systematic reviews on the topic. We therefore conducted a systematic literature review, which included an exhaustive search of the Chinese literature, in an effort to update previously published estimates of the effect of therapeutic zinc. We conducted systematic literature searches in various databases, including the China National Knowledge Infrastructure (CNKI), and abstracted relevant data from studies meeting our inclusion and exclusion criteria. We used STATA 12.0 to pool select outcomes and to generate estimates of percentage difference and relative risk comparing outcomes between zinc and control groups. We identified 89 Chinese and 15 non-Chinese studies for the review, including studies in 10 countries from all WHO geographic regions, and analyzed a total of 18,822 diarrhea cases (9469 zinc and 9353 control). None of the included Chinese studies had previously been included in published pooled effect estimates. Chinese and non-Chinese studies reported the effect of therapeutic zinc supplementation on decreased episode duration, stool output, stool frequency, hospitalization duration and proportion of episodes lasting beyond three and seven days. Pooling Chinese and non-Chinese studies yielded an overall 26% (95% CI: 20%−32%) reduction in the estimated relative risk of diarrhea lasting beyond three days among zinc-treated children. Studies conducted in and outside China report reductions in morbidity as a result of oral therapeutic zinc supplementation for acute diarrhea among children under five years of age. The WHO recommendation for zinc treatment of diarrhea episodes should be supported in all low- and middle-income countries.

A double-blind block randomized clinical trial on the effect of zinc as a treatment for diarrhea in neonatal Holstein calves under natural challenge conditions

Diarrhea is the leading cause of death in neonatal calves and contributes to major economic losses. The objective of this double-blind randomized clinical trial was to evaluate the effect of oral inorganic or organic zinc supplementation as a treatment for neonatal diarrhea in calves. Seventy nine 1 to 8 day old male Holstein calves on a California calf ranch were block randomized to one of 3 treatments within 24h from their first onset of diarrhea. Calves received a daily dose of either a placebo composed of 80 mg of zinc-free powder, 381.54 mg of zinc methionine (Met) (equivalent to 80 mg of zinc), or 99.69 mg of zinc oxide (ZO) (equivalent to 80 mg of zinc) in 2L of a zinc-free oral rehydration solution (ORS). Calves were treated once daily until normal fecal consistency or for a maximum of 14 days. Upon enrollment and exit, calves were weighed, and blood, feces, and liver biopsies were collected for trace mineral analysis. Fecal samples at enrollment and exit were tested for E. coli K99, Cryptosporidium spp., rotavirus and coronavirus. Pre-treatment liver zinc concentrations for the 71 calves in the placebo, zinc Met, and ZO treatment groups were 710.6 (SEM=147.7), 852.3 (SEM=129.6), and 750.7 (SEM=202.9)mg/kg dry weight (DW), respectively. Exit liver zinc concentrations for the calves in the placebo, zinc Met, and ZO treatment groups were 728.9 (SEM=182.9), 1141.0 (SEM=423.8), and 636.8 (SEM=81.5)mg/kg dry weight, respectively. Although statistically non-significant, there were clinically important findings identified for each of zinc Met and ZO treatments. Calves treated with zinc Met gained on average 40 g/day during a diarrhea episode compared to a weight loss of 67 g/day on average in the placebo-treated calves (Power 19.9%). Calves treated with ZO had 1.4 times higher hazard of clinical cure compared to calves in the placebo group (Power 5.3%). Calves that were fecal positive to cryptosporidium spp. at enrollment and treated with zinc Met had higher odds of testing negative at exit compared to placebo calves (Odds Ratio (OR)=16.0). In contrast, calves treated with ZO tended to recover (fecal score=1) one day earlier compared to calves treated with a placebo (8.5 d vs. 9.7 d). The current trial identified clinically important findings that warrant further research to investigate zinc's therapeutic effect for calf diarrhea.

Therapeutic effects of oral zinc supplementation on acute watery diarrhea with moderate dehydration: a double-blind randomized clinical trial

BACKGROUND

To assess the therapeutic effects of oral zinc supplementation on acute watery diarrhea of children with moderate dehydration.

METHODS

All 9-month to 5-year-old children who were admitted with acute watery diarrhea and moderate dehydration to the Children Ward of Motahari Hospital, Urmia, Iran in 2008 were recruited. After the application of the inclusion and exclusion criteria, the patients were randomly allocated to two groups: one group to receive zinc plus oral rehydration solution (ORS) and the other one to receive ORS plus placebo. All the patients were rehydrated using ORS and then receiving ORS for ongoing loss (10 ml/kg after every defecation). Additionally, the patients in the intervention group received zinc syrup (1 mg/kg/day) divided into two doses. A detailed questionnaire was filled daily for each patient by trained pediatrics residents; it contained required demographic characteristics, nutrition and hydration status, and disease progression. The primary outcome (frequency and consistency of diarrhea) and the secondary outcomes (duration of hospitalization and change in patients' weight) were compared between the two groups.

RESULTS

The mean diarrhea frequency (4.5±2.3 vs. 5.3±2.1; P=0.004) was lower in the group receiving zinc +ORS; however, the average weight was relatively similar between the two groups (10.5±3.1 vs. 10.1±2.3; P=0.14). The qualitative assessment of stool consistency also confirmed earlier improvement in the treatment group in the first three days of hospitalization (P <0.05). The mean duration of hospitalization was significantly lower in the patients receiving zinc supplements (2.5±0.7 vs. 3.3±0.8 days; P=0.001).

CONCLUSION

Our results imply the beneficial effects of therapeutic zinc supplementation on disease duration and severity in patients with acute diarrhea and moderate dehydration in Iran.

TRIAL REGISTRATION NUMBER

IRCT201201241580N2.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere. Acute diarrhoea. There is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2175 children, six trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence). Persistent diarrhoea. In children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Therapeutic zinc and copper supplementation in acute diarrhea does not influence short-term morbidity and growth: double-blind randomized controlled trial

Our objective was to evaluate the effect of zinc and copper supplementation in acute diarrhea on morbidity and growth during 12 weeks of follow-up. In a double-blind randomized controlled clinical trial of 724 children aged 6-59 months, none of the 11 evaluated outcomes showed significant association with zinc or zinc and copper supplementation. Thus, therapeutic zinc supplementation may not always yield short-term -benefits.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere.Acute diarrhoeaThere is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2091 children, five trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence).Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Systematic review of diarrhea duration and severity in children and adults in low- and middle-income countries

Background

Diarrhea is a leading cause of morbidity and mortality globally; yet the overall burden of diarrhea in terms of duration and severity has not been quantified. As improvements in treatment lead to decreases in diarrhea mortality, it is important to understand the substantial impact of diarrhea morbidity on disability among children and adults worldwide.

Methods

We conducted a systematic review to generate estimates of duration and severity outcomes for individuals 0-59 mos, 5-15 yrs, and ≥ 16 yrs, and for 3 severity indexes: mild, moderate, and severe.

Results

We estimate that among children under-five, 64.8% of diarrheal episodes are mild, 34.7% are moderate, and 0.5% are severe. On average, mild episodes last 4.3 days, and severe episodes last 8.4 days and cause dehydration in 84.6% of cases. We estimate that among older children and adults, 95% of episodes are mild; 4.95% are moderate; and 0.05% are severe. Among individuals ≥ 16 yrs, severe episodes typically last 2.6 days and cause dehydration in 92.8% of cases.

Conclusions

Moderate and severe episodes constitute a substantial portion of the total envelope of diarrhea among children under-five (35.2%; about 588 million episodes). Among older children and adults, moderate and severe episodes account for a much smaller proportion of the total envelope of diarrhea (5%), but the absolute number of such episodes is noteworthy (about 21.5 million episodes among individuals ≥ 16 yrs). Hence, the global burden of diarrhea consists of significant morbidity, extending beyond episodes progressing to death.

Risk factors for predicting diarrheal duration and morbidity in children with acute diarrhea

OBJECTIVE

To identify baseline risk factors for prolonged diarrheal duration and subsequent complications in children aged 6 to 59 mo with acute diarrhea who participated in a micronutrient clinical trial in a tertiary care hospital.

METHODS

The adjusted odds ratio or incidence risk ratios (IRR) of the baseline variables for prolongation of diarrheal duration (cox proportional hazard model), diarrhea >7 d (multiple logistic regressions), severe dehydration experienced after hospitalization (poisson regression models) was estimated.

RESULTS

Fever (OR 1.10, 95% CI 1.02-1.19, p = 0.02), dehydration (OR 1.32, 95% CI 1.10-1.59, p = 0.003), dysentery (OR 1.41 95% CI 1.09-1.82, p = 0.008), those who received medications (OR 1.19, 95% CI 1.03-1.39, p = 0.02), and weight for age Z-score ≤2 (OR 1.25, 95% CI 1.07-1.46, p = 0.004) were at a greater risk of prolonged diarrhea. Diarrhea >7 d was associated with younger age (OR 1.08, 95% CI 1.03-1.14, p = 0.003), female child (OR 2.33, 95% CI 1.19-4.55, p = 0.013), diarrheal duration before enrolment (OR 1.06, 95% CI 1.04-1.09, p < 0.001), fever (OR 1.7, 95% CI 1.23-2.49, p = 0.002) and the weight for age Z-score ≤2 (OR 4.32, 95% CI 2.03-9.16, p < 0.001). Severe dehydration after hospitalization was associated with dehydration at baseline (OR 6.7, 95% CI 2-3.0, p < 0.001), incomplete immunization (OR 3.33, 95% CI 1.5-7.69, p < 0.001), failure to receive any medication(OR 3.03, 95% CI 1.26-7.14, p = 0.01).

CONCLUSIONS

Few studies assess risk factors for diarrheal morbidity prospectively. The present study showed that children of acute diarrhea with above risk factors need stricter monitoring for complications to reduce diarrheal mortality.

Zinc, vitamin A, and micronutrient supplementation in children with diarrhea: a randomized controlled clinical trial of combination therapy versus monotherapy

OBJECTIVE

To compare the clinical efficacy of supplementation of zinc, zinc plus vitamin A, and zinc plus combination of micronutrients and vitamins (iron, copper, selenium, vitamin B(12), folate, and vitamin A) on acute diarrhea in children.

STUDY DESIGN

This was a double-blind, randomized, placebo-controlled trial. Children aged 6 to 24 months with diarrhea and moderate dehydration were randomized to receive zinc plus placebo vitamin A (group 1), zinc plus other micronutrients plus vitamin A (group 2), zinc plus vitamin A (group 3), or placebo (group 4) as an adjunct to oral rehydration solution. Duration, volume of diarrhea, and consumption of oral rehydration solution were compared as outcome variables within the supplemented groups and with the placebo group.

RESULTS

The 167 study subjects included 41 in group 1, 39 in group 2, 44 in group 3, and 43 in group 4. All 3 supplemented groups demonstrated a significant reduction in outcome variables (P < .0001) compared with the placebo group. Group 3 had the lowest reduction of outcome variables and group 2 had a speedy recovery, but differences among the supplemented groups were not statistically significant.

CONCLUSIONS

Supplementation with a combination of micronutrients and vitamins was not superior to zinc alone, confirming the clinical benefit of zinc in children with diarrhea.

Efficacy of a new hypotonic oral rehydration solution containing zinc and prebiotics in the treatment of childhood acute diarrhea: a randomized controlled trial

OBJECTIVE

To evaluate the efficacy of a hypotonic oral rehydration solution (ORS) containing zinc and prebiotics for treatment of acute diarrhea in children.

STUDY DESIGN

We conducted a single-blind, prospective, controlled trial including children (age range, 3-36 months) with acute diarrhea randomly assigned to standard hypotonic ORS (group 1) or to new hypotonic ORS containing zinc and prebiotics (group 2). The main outcome was the rate of resolution of diarrhea at 72 hours.

RESULTS

A total of 60 children in group 1 (34 male; mean age, 18.58 months; 95% CI, 15.5-21.6) and 59 in group 2 (36 male; mean age, 19.26 months; 95% CI, 15.9-22.6) completed the study protocol. The rate of diarrhea resolution at 72 hours was higher in group 2 (50% versus 72.9%, P = .010). Total ORS intake in the first 24 hours was higher in group 2 (50 mL/kg; 95% CI, 41-59 versus 22 mL/kg; 95% CI, 17-29; P < .001). The mean number of missed working days by the parents of children in group 2 was lower (0.39; 95% CI, 0.08-0.70 versus 1.45; 95% CI 1.02-1.88; P < .001). Fewer patients in group 2 needed adjunctive drugs for the treatment of diarrhea 6/59 versus 19/60, P = .004. No adverse events were observed in either of the two groups.

CONCLUSION

The addition of zinc and prebiotics to ORS limits diarrhea duration in children.

Update on prolonged and persistent diarrhea in children

PURPOSE OF REVIEW

To highlight recent advances in our understanding of prolonged episodes of acute diarrhea and persistent diarrhea in children. The focus is on the contribution of these illnesses to the global burden of diarrhea, their impact on childhood growth and development, novel epidemiologic links between prolonged and persistent diarrheal episodes, and strategies for their prevention and management.

RECENT FINDINGS

Although less common than acute diarrhea, prolonged and persistent episodes of diarrhea in childhood constitute a significant portion of the global burden of diarrhea. These episodes also play a key role in the vicious cycle of childhood diarrhea and malnutrition in which undernutrition is both a risk factor and an outcome of diarrhea. Increased efforts to provide WHO-recommended zinc therapy for all children with diarrhea in developing countries will significantly reduce morbidity and mortality. In children who develop persistent diarrhea, yogurt-based or amino acid-based diets may accelerate their recovery.

SUMMARY

In addition to increased implementation of strategies already known to effectively prevent and manage acute diarrhea, further research is needed to address the recognition, prevention, and treatment of prolonged episodes of acute diarrhea and persistent diarrhea in resource-limited settings.

Influence of zinc supplementation in acute diarrhea differs by the isolated organism

Zinc supplementation is recommended in all acute diarrheas in children from developing countries. We aimed to assess whether zinc supplementation would be equally effective against all the common organisms associated with acute diarrheas. We used data on 801 children with acute diarrhea recruited in a randomized, double blind controlled trial (ISRCTN85071383) of zinc and copper supplementation. Using prespecified subgroup analyses, multidimensionality reduction analyses, tests of heterogeneity, and stepwise logistic regression for tests of interactions, we found that the influence of zinc on the risk of diarrhea for more than 3 days depended on the isolated organism—beneficial in Klebsiella, neutral in Esherichia coli and parasitic infections, and detrimental in rotavirus coinfections. Although we found similar results for the outcome of high stool volume, the results did not reach statistical significance. Our findings suggest that the current strategy of zinc supplementation in all cases of acute diarrheas in children may need appropriate fine tuning to optimize the therapeutic benefit based on the causative organism, but further studies need to confirm and extend our findings.

Therapeutic value of zinc supplementation in acute and persistent diarrhea: a systematic review

BACKGROUND

For over a decade, the importance of zinc in the treatment of acute and persistent diarrhea has been recognized. In spite of recently published reviews, there remain several unanswered questions about the role of zinc supplementation in childhood diarrhea in the developing countries. Our study aimed to assess the therapeutic benefits of zinc supplementation in the treatment of acute or persistent diarrhea in children, and to examine the causes of any heterogeneity of response to zinc supplementation.

METHODS AND FINDINGS

EMBASE, MEDLINE and CINAHL databases were searched for published reviews and meta-analyses on the use of zinc supplementation for the prevention and treatment of childhood diarrhea. Additional RCTs published following the meta-analyses were also sought. The reviews and published RCTs were qualitatively mapped followed by updated random-effects meta-analyses, subgroup meta-analyses and meta-regression to quantify and characterize the role of zinc supplementation with diarrhea-related outcomes. We found that although there was evidence to support the use of zinc to treat diarrhea in children, there was significant unexplained heterogeneity across the studies for the effect of zinc supplementation in reducing important diarrhea outcomes. Zinc supplementation reduced the mean duration of diarrhea by 19.7% but had no effect on stool frequency or stool output, and increased the risk of vomiting. Our subgroup meta-analyses and meta-regression showed that age, stunting, breast-feeding and baseline zinc levels could not explain the heterogeneity associated with differential reduction in the mean diarrheal duration. However, the baseline zinc levels may not be representative of the existing zinc deficiency state.

CONCLUSIONS

Understanding the predictors of zinc efficacy including the role of diarrheal disease etiology on the response to zinc would help to identify the populations most likely to benefit from supplementation. To improve the programmatic use of zinc, further evaluations of the zinc salts used, the dose, the frequency and duration of supplementation, and its acceptability are required. The significant heterogeneity of responses to zinc suggests the need to revisit the strategy of universal zinc supplementation in the treatment children with acute diarrhea in developing countries.

Zinc for the treatment of diarrhoea: effect on diarrhoea morbidity, mortality and incidence of future episodes

Background Zinc supplementation for the treatment of diarrhoea has been shown to decrease the duration and severity of the diarrhoeal episode, diarrhoea hospitalization rates and, in some studies, all-cause mortality. Using multiple outcome measures, we sought to estimate the effect of zinc for the treatment of diarrhoea on diarrhoea mortality and subsequent pneumonia mortality.

Methods We conducted a systematic review of efficacy and effectiveness studies. We used a standardized abstraction and grading format and performed meta-analyses for all outcomes with ≥2 data points. The estimated effect on diarrhoea mortality was determined by applying the standard Child Health Epidemiology Reference Group rules for multiple outcomes.

Results We identified 13 studies for abstraction. Zinc supplementation decreased the proportion of diarrhoeal episodes which lasted beyond 7 days, risk of hospitalization, all-cause mortality and diarrhoea mortality. Using diarrhoea hospitalizations as the closest and most conservative possible proxy for diarrhoea mortality, zinc for the treatment of diarrhoea is estimated to decrease diarrhoea mortality by 23%.

Conclusion Zinc is an effective therapy for diarrhoea and will decrease diarrhoea morbidity and mortality when introduced and scaled-up in low-income countries.

Oral zinc for treating diarrhoea in children

BACKGROUND

Diarrhoea causes around two million child deaths annually. Zinc supplementation could help reduce the duration and severity of diarrhoea, and is recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH STRATEGY

In November 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation (>/= 5 mg/day for any duration) with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and methodological quality, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.

MAIN RESULTS

Eighteen trials enrolling 6165 participants met our inclusion criteria. In acute diarrhoea, zinc resulted in a shorter diarrhoea duration (MD -12.27 h, 95% CI -23.02 to -1.52 h; 2741 children, 9 trials), and less diarrhoea at day three (RR 0.69, 95% CI 0.59 to 0.81; 1073 children, 2 trials), day five (RR 0.55, 95% CI 0.32 to 0.95; 346 children, 2 trials), and day seven (RR 0.71, 95% CI 0.52 to 0.98; 4087 children, 7 trials). The four trials (1458 children) that reported on diarrhoea severity used different units and time points, and the effect of zinc was less clear. Subgroup analyses by age (trials with only children aged less than six months) showed no benefit with zinc. Subgroup analyses by nutritional status, geographical region, background zinc deficiency, zinc type, and study setting did not affect the results' significance. Zinc also reduced the duration of persistent diarrhoea (MD -15.84 h, 95% CI -25.43 to -6.24 h; 529 children, 5 trials). Few trials reported on severity, and results were inconsistent. No trial reported serious adverse events, but vomiting was more common in zinc-treated children with acute diarrhoea (RR 1.71, 95% 1.27 to 2.30; 4727 children, 8 trials).

AUTHORS' CONCLUSIONS

In areas where diarrhoea is an important cause of child mortality, research evidence shows zinc is clearly of benefit in children aged six months or more.