Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months

Analysis of the Perinatal Care System in a Remote and Mountainous District of Nepal

INTRODUCTION

Despite significant improvements in recent years, maternal and neonatal health outcomes remain poor in many regions of the world. One such area is in the remote mountainous regions of Nepal. The purpose of this study is to describe the current antenatal care practices and delivery support in a mountainous district of Nepal.

METHODS

This study took place in Solukhumbu District between December 2015 and February 2018. A household survey was created using evidence-based maternal and neonatal care indicators. Women who had delivered within the previous two years were surveyed regarding antenatal and delivery care they received. A standardized health facility survey was used to evaluate the operational status of health facilities. The study was approved by the Nepal Ministry of Health and the University of Utah IRB.

RESULTS

A total of 487 households and 19 facilities were surveyed. 35.7% (174/487) of deliveries occurred in a health facility (hospital, primary health care center or birthing center). 35.2% (171/486) of deliveries were attended by a skilled birth attendant. 52.8% (47/89) of women who did not deliver in a facility noted that transportation issues and not having sufficient time to travel during labor prevented them from delivering in a facility. No health posts had staff trained in obstetric and neonatal emergencies.

DISCUSSION

The majority of women in Solukhumbu District do not receive high quality antenatal and delivery care. An intervention that would make antenatal care and delivery support more accessible could improve maternal and infant outcomes in this district and other similar regions.

Identifying Programmatic Factors that Increase Likelihood of Health Facility Delivery: Results from a Community Health Worker Program in Zanzibar

INTRODUCTION

Community health worker (CHW) interventions have been utilized to address barriers that prevent pregnant women from delivering in health facilities in low- and middle-income countries (LMICs). The objective of this research was to assess the programmatic factors that increase the likelihood of health facility delivery within a large digital health-supported CHW program in Zanzibar, Tanzania.

METHODS

This study included 36,693 women who were enrolled in the Safer Deliveries program with a live birth between January 1, 2017 and July 31, 2019. We assessed whether long-term enrollment, recency of CHW pregnancy visit prior to delivery, and number of routine home pregnancy visits were associated with an increased likelihood of health facility delivery compared to home delivery. We used Chi-squared tests to assess bivariate relationships and performed logistic regression analyses to assess the association between each programmatic variable and health facility delivery, adjusting for relevant confounders.

RESULTS

We found that long-term enrollment was significantly associated with increased likelihood of health facility delivery, with the strongest relationship among women with a previous home delivery (OR = 1.4, 95%CI [1.0,1.7]). Among first-time mothers, two or more pregnancy visits by a CHW was positively associated with health facility delivery (OR = 1.8, 95%CI [1.2, 2.7]). Recent pregnancy visit by a CHW was positively associated with health facility delivery, but was not significant at the α = 0.05 level.

DISCUSSION

In this program, we found evidence that at least two routine home pregnancy visits, longer length of enrollment in the program, and recency of home visit to the delivery date were strategies to increase health facility delivery rates among enrolled mothers. Maternal and child health programs should undertake similar evaluations to improve program delivery.

Zinc Intakes and Health Outcomes: An Umbrella Review

It is widely accepted that the zinc element is crucial in human beings. Zinc has gained more attention during the COVID-19 pandemic due to its utilization for the treatment and prevention of respiratory tract infections. However, some studies also pointed out that zinc intake might cause unwanted side effects and even be dangerous when overdosed. To reveal the relationship between zinc intake and health outcomes, we performed an umbrella review from human studies. In total, the umbrella review included 43 articles and identified 11 outcomes for dietary zinc intake and 86 outcomes for supplementary zinc intake. Dietary zinc intake in the highest dose would decrease the risk of overall and specific digestive tract cancers, depression, and type 2 diabetes mellitus (T2DM) in adults. Supplementary zinc consumption in adults was linked to an improvement of depression, antioxidant capacity and sperm quality, higher serum zinc concentration, and lower concentration of inflammatory markers. Zinc supplementation in children would reduce the incidence of diarrhea and pneumonia, improve zinc deficiency and boost growth. However, zinc might not decrease all-cause mortality in adults or the in-hospital mortality of COVID-19. And better maternal and neonatal outcomes may not derive from pregnant women who consumed higher or lower doses of zinc supplementation (>20 mg/day and <20 mg/day, respectively). Dose-response analyses revealed that a daily 5 mg increment of zinc would lower the risk of colorectal and esophageal cancer, whereas a large dose of zinc supplementation (daily 100 mg) showed no benefit in reducing prostate cancer risk.

Antioxidant, Antigenotoxic, and Hepatic Ameliorative Effects of Quercetin/Zinc Complex on Cadmium-Induced Hepatotoxicity and Alterations in Hepatic Tissue Structure

Applications of medicinal uses of metals and their complexes have been gaining major clinical significance, especially during the COVID-19 pandemic. The ligation behavior of quercetin (Q), a flavonoid, and Zn metal, i.e., the Zn/Q complex, was fully characterized based on molar conductance, infrared (IR) spectra, elemental analysis, electronic spectra, thermogravimetric analysis, proton nuclear magnetic resonance (1H-NMR), and transmission electron microscopy (TEM) in our lab. Hepatotoxicity was induced by cadmium (CdCl2). A total of 40 male albino rats were randomly distributed into the following four groups: Control, hepatotoxic group (CdCl2), Zn/Q-treated group, and group treated with a combination of CdCl2 and Zn/Q. Serum hepatic enzymes (AST, ALT, and LDH), total protein, and enzymatic and nonenzymatic antioxidant levels were determined. Histology and TEM for hepatic tissues, in addition to the gene expression of SOD as an antioxidant enzyme in the hepatic tissues, were evaluated. The Q/Zn treatment demonstrated potent protective effects against CdCl2-induced sever oxidative stress and suppressed hepatic toxicity, genotoxicity, liver enzyme disturbances, and structural alterations. In conclusion, the Zn/Q complex produced a high potent antioxidant effect against the oxidative injury and genotoxicity induced by CdCl2 and could be considered to be a potent ameliorative hepatoprotective agent against CdCl2 hepatotoxicity, which could be beneficial during the COVID-19 pandemic.

Effects of therapeutic zinc supplementation for diarrhea and two preventive zinc supplementation regimens on the incidence and duration of diarrhea and acute respiratory tract infections in rural Laotian children: A randomized controlled trial

Background

Diarrhea and respiratory tract infections are leading causes of childhood morbidity and mortality. This individually randomized, double-blind placebo-controlled trial was designed to evaluate the effects of different zinc supplementation regimens on the incidence and duration of diarrhea and acute lower (ALRI) and upper (AURI) respiratory tract infections among rural Laotian children. The study included 3407 children, 6-23 months at enrollment.

Methods

Children were randomized to one of four study groups: therapeutic zinc supplements for diarrhea treatment (20 mg/d for 10 days with each episode; TZ), daily preventive zinc tablets (7 mg/d; PZ), daily multiple micronutrient powder (10 mg/d zinc, 6 mg/d iron and 13 other micronutrients; MNP), or daily placebo powder for 9 months. Incidence and duration of diarrhea (≥3 liquid stools/24 hours), ALRI (persistent cough with wheezing, stridor or chest in-drawing) and AURI (purulent nasal discharge with cough) were assessed by parental report during weekly home visits and analyzed using negative binomial models.

Results

Baseline mean age was 14.2 ± 5.1 months, and 71% had low plasma zinc (<65 μg/dL). Overall diarrhea incidence (0.61 ± 0.01 episodes/100 days at risk) and duration (2.12 ± 0.03 days/episode) did not differ by study group. Age modified the impact of the interventions on diarrhea incidence (P = 0.06) and duration (P = 0.01). In children >18 months, TZ reduced diarrhea incidence by 24% vs MNP (P = 0.035), and 36% vs Control (P = 0.004), but there was no difference with PZ. This patterned remained when analyses were restricted to diarrhea episode occurring after the first treatment with TZ. Also, in children >18 months, TZ reduced diarrhea duration by 15% vs PZ (P = 0.03), and 16% vs Control (P = 0.03), but there was no difference with MNP. There were no overall effects of study group on incidence of ALRI (overall mean 0.005 ± 0.001 episodes/100 days, P = 0.14) or AURI (overall mean 0.09 ± 0.01 episodes/100 days, P = 0.72).

Conclusions

There was no overall impact of TZ, PZ or MNP on diarrhea, ALRI and AURI. However, in children >18 months, TZ significantly reduced both the duration of diarrhea episodes and the incidence of future diarrhea episodes compared with placebo.

Trial registration

ClinicalTrials.gov: NCT02428647.

Association of nutritional support programs with zinc deficiency in Colombian children: a cross-sectional study

Background

Zinc is an essential trace element that plays a key role in the immune, gastrointestinal, respiratory and nervous systems. In Colombia, a vast percentage of children live in low-income households with food insecurity and nutritional deficiencies, including zinc. In an effort to improve children’s well-being, public health measures such as nutritional support programs that provide meals have targeted the poorest populations. The aim of the present study was to assess the role of nutritional support programs on zinc deficiency in Colombian children, while considering their wealth and food security.

Methods

Cross-sectional study using data from the 2010 Colombian National Nutrition Survey, a population-based study representative of Colombia. A total of 4275 children between 12 and 59 months of age were included in the study. Stepwise logistic regressions were modelled with SPSS, first for zinc deficiency on wealth and food security, then adding enrolment in a nutritional support program, and finally, adjusting for socio-demographic variables.

Results

A zinc deficiency prevalence of 49% was found. The adjusted models showed an association of wealth quintiles: very poor (OR = 1.48) and poor (OR = 1.39), food security (OR = 0.75) and enrolment in a nutritional support program (OR = 0.76) with zinc deficiency. Enrolment in nutritional programs did not modify the relationship of wealth and food security to zinc deficiency.

Conclusion

Zinc deficiency is associated with wealth, food security and enrolment in nutritional support programs. Nutritional programs may be a good alternative against zinc deficiency, if they focus appropriately on the needs of children according to their wealth and food security.

Dietary zinc and the control of Streptococcus pneumoniae infection

Human zinc deficiency increases susceptibility to bacterial infection. Although zinc supplementation therapies can reduce the impact of disease, the molecular basis for protection remains unclear. Streptococcus pneumoniae is a major cause of bacterial pneumonia, which is prevalent in regions of zinc deficiency. We report that dietary zinc levels dictate the outcome of S. pneumoniae infection in a murine model. Dietary zinc restriction impacts murine tissue zinc levels with distribution post-infection altered, and S. pneumoniae virulence and infection enhanced. Although the activation and infiltration of murine phagocytic cells was not affected by zinc restriction, their efficacy of bacterial control was compromised. S. pneumoniae was shown to be highly sensitive to zinc intoxication, with this process impaired in zinc restricted mice and isolated phagocytic cells. Collectively, these data show how dietary zinc deficiency increases sensitivity to S. pneumoniae infection while revealing a role for zinc as a component of host antimicrobial defences.

Zinc deficiency affects one-third of the world’s population and is associated with an increased susceptibility to bacterial infection. Despite this, the molecular basis for how zinc deficiency compromises host control of infection remains to be understood. We show that dietary zinc deficiency impacts host tissue zinc abundances and its mobilization during infection by the major respiratory pathogen Streptococcus pneumoniae. Zinc acts as a direct antimicrobial against the pathogen, mobilized by phagocytic cells as a component of the innate immune response. Although immune activation and infiltration of phagocytic cells is unaffected by host zinc status, the lack of antimicrobial zinc compromises bacterial control in zinc deficient hosts. These findings highlight the importance of zinc sufficiency in resisting bacterial infection.

Zinc Supplementation Promotes a Th1 Response and Improves Clinical Symptoms in Fewer Hours in Children With Pneumonia Younger Than 5 Years Old. A Randomized Controlled Clinical Trial

Background: Pneumonia caused 704,000 deaths in children younger than 5 years in 2015. Zinc is an important micronutrient due to its role in immune function. Since 2004, WHO recommends zinc supplementation for children with diarrhea to shorten the duration and decrease severity. Zinc supplementation for children with pneumonia is controversial. Methods: A randomized controlled clinical trial was conducted, and 103 children 1 month to 5 years old with pneumonia were included. Zinc or placebo was given during hospitalization. Clinical symptoms were recorded, and a blood draw was obtained to determine serum zinc levels, lymphoproliferation, and cytokines at hospitalization and at discharge of the patient; a nasal wash was obtained to detect viral or bacterial pathogens by multiplex RT-PCR. Results: Zinc supplementation improved in fewer hours the clinical status (76 ± 7 vs. 105 ± 8, p = 0.01), the respiratory rate (37 ± 6 vs. 57 ± 7, p = 0.04), and the oxygen saturation (53 ± 7 vs. 87 ± 9, p = 0.007) compared to the placebo group. An increase in IFNγ and IL-2 after treatment in the zinc group was observed. Conclusions: Zinc supplementation improved some clinical symptoms in children with pneumonia in fewer hours and induced a cellular immune response. Clinical Trial Registration: The trial was retrospectively registered in ClinicalTrials.gov, identifier NCT03690583, URL https://clinicaltrials.gov/ct2/show/NCT03690583?term=zinc+children&cond=Pneumonia&draw=2&rank=1.

Zinc as an adjunct therapy in the management of severe pneumonia among Gambian children: randomized controlled trial

Background

The benefit of zinc as an adjunct therapy for severe pneumonia is not established. We assessed the benefit of adjunct zinc therapy for severe pneumonia in children and determined whether the study children were zinc deficient.

Methods

This was a randomized, parallel group, double-blind, placebo-controlled trial with an allocation ratio of 1:1 conducted in children with severe pneumonia to evaluate the efficacy of daily zinc as an adjunct treatment in preventing 'treatment failure' (presence of any sign of severe pneumonia) on day-5 and day-10 and in reducing the time to resolution of signs of severe pneumonia. Six hundred and four children 2-59 months of age presenting with severe pneumonia at six urban and rural health care facilities in The Gambia were individually randomised to receive placebo (n = 301) or zinc (n = 303) for seven days. To determine if the study children were zinc deficient, supplementation was continued in a randomly selected subgroup of 121 children from each arm for six months post-enrolment, and height-gain, nutritional status, plasma zinc concentrations, and immune competence were compared.

Results

Percentage of treatment failure were similar in placebo and zinc arms both on day 5 (14.0% vs 14.1%) and day 10 (5.2% vs 5.9%). The time to recovery from lower chest wall indrawing and sternal retraction was longer in the placebo compared to zinc arm (24.4 vs 23.0 hours; P = 0.011 and 18.7 vs 11.0 hours; P = 0.006 respectively). The time to resolution for all respiratory symptoms of severity was not significantly different between placebo and zinc arms (42.3 vs 30.9 hours respectively; P = 0.242). In the six months follow-up sub-group, there was no significant difference in height gain, height-for-age and weight-for-height Z-scores, mid upper arm circumference, plasma zinc concentrations, and anergy at six months post-enrolment.

Conclusions

In this population, zinc given as an adjunct treatment for severe pneumonia showed no benefit in treatment failure rates, or clinically important benefit in time to recovery from respiratory symptoms and showed marginal benefit in rapidity of resolution of some signs of severity. This finding does not support routine use of zinc as an adjunct treatment in severe pneumonia in generally zinc replete children.

Trial registration

ISRCTN33548493.

Zinc Supplementation in Adult Mechanically Ventilated Trauma Patients is Associated with Decreased Occurrence of Ventilator-associated Pneumonia: A Secondary Analysis of a Prospective, Observational Study

BACKGROUND

Ventilator-associated pneumonia (VAP) is a type of lung infection that typically affects critically ill patients undergoing mechanical ventilation (MV) in the Intensive Care Unit (ICU). The aim of this analysis is to determine potential association between zinc supplementation with the occurrence of VAP in adult mechanically ventilated trauma patients.

SUBJECTS AND METHODS

This secondary analysis of a prospective observational study was carried out over a period of 1 year in ICUs of one teaching hospital in Iran. A total of 186 adults mechanically ventilated trauma patients, who required at least 48 h of MV and received zinc sulfate supplement (n = 82) or not (n = 104) during their ICU stay, were monitored for the occurrence of VAP until their discharge from the ICU or death.

RESULTS

Forty-one of 186 patients developed VAP, 29.09 days after admission (95% confidence interval [CI]: 26.27-31.9). The overall incidence of VAP was 18.82 cases per 1000 days of intubation (95% CI: 13.86-25.57). Patients who received zinc sulfate supplement have smaller hazard of progression to VAP than others (hazard ratio: 0.318 [95% CI: 0.138-0.732]; P < 0.0001).

CONCLUSION

The findings show that zinc supplementation may be associated with a significant reduction in the occurrence of VAP in adult mechanically ventilated trauma patients. Further well-designed randomized clinical trials to confirm the efficacy of this potential preventive modality are warranted.

Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily zinc supplements have been reported to prevent acute lower respiratory tract infection (LRTI) and reduce child mortality. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.

SEARCH METHODS

We searched CENTRAL (Issue 21 October 2016), MEDLINE (1966 to October 2016), Embase (1974 to October 2016), LILACS (1982 to October 2016), CINAHL (1981 to October 2016), Web of Science (1985 to October 2016) and IMSEAR (1980 to October 2016).

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating zinc supplementation for the prevention of pneumonia in children aged from 2 months to 59 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We did not identify any new studies for inclusion in this update. We included six studies that involved 5193 participants.Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (fixed-effect risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, six studies, low-quality evidence) and prevalence of pneumonia by 41% (random-effects RR 0.59; 95% CI 0.35 to 0.99, one study, n = 609, low-quality evidence). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (fixed-effect RR 0.79; 95% CI 0.0.71 to 0.88, four studies, n = 3261), but had no effect on lower specificity pneumonia case definition (i.e. age-specific fast breathing with or without lower chest indrawing) (fixed-effect RR 0.95; 95% CI 0.86 to 1.06, four studies, n = 1932).

AUTHORS' CONCLUSIONS

Zinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia.

Effect of zinc supplementation on infants with severe pneumonia

BACKGROUND

Pneumonia is a common respiratory infectious disease in infancy. Previous work shows controversial results on the benefit of zinc supplementation in patients with pneumonia. We conducted this study to investigate serum zinc status amongst infants with severe pneumonia and the clinical impact that zinc supplementation has on those patients with low serum zinc levels.

METHODS

This study design was a non-blinded prospective randomized controlled trial. The study is approved by the Ethics Committees of Beijing Children's Hospital. A total of 96 infants diagnosed with severe pneumonia and hospitalized in the pediatric intensive care unit between November 2011 and January 2012 were enrolled. Enrolled patients were divided into low serum zinc and normal serum zinc group. The low serum zinc group was randomized into treatment and control groups. Only the treatment group received zinc supplementation within 48-72 hours after hospitalization.

RESULTS

The prevalence of zinc deficiency on admission was 76.0%. The low zinc level was most apparent in infants between 1 and 3 months of age. The serum zinc level increased in the zinc treatment group and returned to a normal level (median, 53.20 μmol/L) on day 12±2. There was no statistical difference in the pediatric critic illness score, lung injury score, length of hospital stay, and duration of mechanical ventilation between the zinc treatment group and control group.

CONCLUSION

Zinc deficiency is common in infants with severe pneumonia. Normalization of zinc levels with zinc supplementation did not improve clinical outcomes of infants with pneumonia.

Oral Toxicity Study and Skin Sensitization Test of a Cricket

Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource.

Effect of increased concentrations of atmospheric carbon dioxide on the global threat of zinc deficiency: a modelling study

BACKGROUND

Increasing concentrations of atmospheric carbon dioxide (CO2) lower the content of zinc and other nutrients in important food crops. Zinc deficiency is currently responsible for large burdens of disease globally, and the populations who are at highest risk of zinc deficiency also receive most of their dietary zinc from crops. By modelling dietary intake of bioavailable zinc for the populations of 188 countries under both an ambient CO2 and elevated CO2 scenario, we sought to estimate the effect of anthropogenic CO2 emissions on the global risk of zinc deficiency.

METHODS

We estimated per capita per day bioavailable intake of zinc for the populations of 188 countries at ambient CO2 concentrations (375-384 ppm) using food balance sheet data for 2003-07 from the Food and Agriculture Organization. We then used previously published data from free air CO2 enrichment and open-top chamber experiments to model zinc intake at elevated CO2 concentrations (550 ppm, which is the concentration expected by 2050). Estimates developed by the International Zinc Nutrition Consultative Group were used for country-specific theoretical mean daily per-capita physiological requirements for zinc. Finally, we used these data on zinc bioavailability and population-weighted estimated average zinc requirements to estimate the risk of inadequate zinc intake among the populations of the different nations under the two scenarios (ambient and elevated CO2). The difference between the population at risk at elevated and ambient CO2 concentrations (ie, population at new risk of zinc deficiency) was our measure of impact.

FINDINGS

The total number of people estimated to be placed at new risk of zinc deficiency by 2050 was 138 million (95% CI 120-156). The people likely to be most affected live in Africa and South Asia, with nearly 48 million (32-63) residing in India alone. Global maps of increased risk show significant heterogeneity.

INTERPRETATION

Our results indicate that one heretofore unquantified human health effect associated with anthropogenic CO2 emissions will be a significant increase in the human population at risk of zinc deficiency. Our country-specific findings can be used to help guide interventions aimed at reducing this vulnerability.

FUNDING

Bill & Melinda Gates Foundation, Winslow Foundation.

Host-imposed manganese starvation of invading pathogens: two routes to the same destination

During infection invading pathogens must acquire all essential nutrients, including first row transition metals, from the host. To combat invaders, the host exploits this fact and restricts the availability of these nutrients using a defense mechanism known as nutritional immunity. While iron sequestration is the most well-known aspect of this defense, recent work has revealed that the host restricts the availability of other essential elements, notably manganese (Mn), during infection. Furthermore, these studies have revealed that the host utilizes multiple strategies that extend beyond metal sequestration to prevent bacteria from obtaining these metals. This review will discuss the mechanisms by which bacteria attempt to obtain the essential first row transition metal ion Mn during infection, and the approaches utilized by the host to prevent this occurrence. In addition, this review will discuss the impact of host-imposed Mn starvation on invading bacteria.

Biomarkers of Nutrition for Development (BOND)-Zinc Review

Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc Expert Panel recommends 3 measurements for estimating zinc status: dietary zinc intake, plasma zinc concentration (PZC), and height-for-age of growing infants and children. The amount of dietary zinc potentially available for absorption, which requires an estimate of dietary zinc and phytate, can be used to identify individuals and populations at risk of zinc deficiency. PZCs respond to severe dietary zinc restriction and to zinc supplementation; they also change with shifts in whole-body zinc balance and clinical signs of zinc deficiency. PZC cutoffs are available to identify individuals and populations at risk of zinc deficiency. However, there are limitations in using the PZC to assess zinc status. PZCs respond less to additional zinc provided in food than to a supplement administered between meals, there is considerable interindividual variability in PZCs with changes in dietary zinc, and PZCs are influenced by recent meal consumption, the time of day, inflammation, and certain drugs and hormones. Insufficient data are available on hair, urinary, nail, and blood cell zinc responses to changes in dietary zinc to recommend these biomarkers for assessing zinc status. Of the potential functional indicators of zinc, growth is the only one that is recommended. Because pharmacologic zinc doses are unlikely to enhance growth, a growth response to supplemental zinc is interpreted as indicating pre-existing zinc deficiency. Other functional indicators reviewed but not recommended for assessing zinc nutrition in clinical or field settings because of insufficient information are the activity or amounts of zinc-dependent enzymes and proteins and biomarkers of oxidative stress, inflammation, or DNA damage.

Zinc supplementation for the treatment of measles in children

BACKGROUND

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.

OBJECTIVES

To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles.

SEARCH METHODS

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.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles.

DATA COLLECTION AND ANALYSIS

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.

MAIN RESULTS

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.

AUTHORS' CONCLUSIONS

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.

Zinc supplementation for improving pregnancy and infant outcome

BACKGROUND

It has been suggested that low serum zinc levels may be associated with suboptimal outcomes of pregnancy such as prolonged labour, atonic postpartum haemorrhage, pregnancy-induced hypertension, preterm labour and post-term pregnancies, although many of these associations have not yet been established.

OBJECTIVES

To assess the effects of zinc supplementation in pregnancy on maternal, fetal, neonatal and infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials of zinc supplementation in pregnancy. We excluded quasi-randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Three review authors applied the study selection criteria, assessed trial quality and extracted data. When necessary, we contacted study authors for additional information. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

We included 21 randomised controlled trials (RCTs) reported in 54 papers involving over 17,000 women and their babies. One trial did not contribute data. Trials were generally at low risk of bias. Zinc supplementation resulted in a small reduction in preterm birth (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.76 to 0.97 in 16 RCTs; 16 trials of 7637 women). This was not accompanied by a similar reduction in numbers of babies with low birthweight (RR 0.93, 95% CI 0.78 to 1.12; 14 trials of 5643 women). No clear differences were seen between the zinc and no zinc groups for any of the other primary maternal or neonatal outcomes, except for induction of labour in a single trial. No differing patterns were evident in the subgroups of women with low versus normal zinc and nutrition levels or in women who complied with their treatment versus those who did not. The GRADE quality of the evidence was moderate for preterm birth, small-for-gestational age, and low birthweight, and low for stillbirth or neonatal death and birthweight.

AUTHORS' CONCLUSIONS

The evidence for a 14% relative reduction in preterm birth for zinc compared with placebo was primarily represented by trials involving women of low income and this has some relevance in areas of high perinatal mortality. There was no convincing evidence that zinc supplementation during pregnancy results in other useful and important benefits. Since the preterm association could well reflect poor nutrition, studies to address ways of improving the overall nutritional status of populations in impoverished areas, rather than focusing on micronutrient and or zinc supplementation in isolation, should be an urgent priority.

Evaluating the cost-effectiveness of preventive zinc supplementation

BACKGROUND

Even though the WHO currently recommends zinc for diarrhea management, no consensus has been reached with respect to routine distribution of zinc for preventive reasons. We reviewed the health impact of preventive zinc interventions, and evaluated the relative cost effectiveness of currently feasible interventions.

METHODS

Using the latest relative risk estimates reported in the literature, we parameterized a health impact model, and calculated the expected benefits of zinc supplementation in a representative low-income country. We then computed the cost and cost-effectiveness for three delivery mechanisms: the direct distribution of zinc supplements, the distribution of micronutrient biscuits including zinc, and the distribution of zinc through water filtration systems.

RESULTS

Combining all health outcomes and impact estimates, we find that systematic zinc supplementation among children of ages one to five would avert 1.423 DALYs per 100 households and year in least developed countries. The estimated cost per DALY is US$ 606 for pill supplementation, US$ 1211 for micronutrient biscuits, and US$ 879 per DALY saved for water filtration systems.

CONCLUSIONS

Preventive zinc supplementation to children of ages 1-5 appears to be a highly cost-effective intervention in typical developing country settings. More research will be needed to determine the most effective mechanism to deliver zinc to this target population.

Preventive zinc supplementation for children, and the effect of additional iron: a systematic review and meta-analysis

OBJECTIVE

Zinc deficiency is widespread, and preventive supplementation may have benefits in young children. Effects for children over 5 years of age, and effects when coadministered with other micronutrients are uncertain. These are obstacles to scale-up. This review seeks to determine if preventive supplementation reduces mortality and morbidity for children aged 6 months to 12 years.

DESIGN

Systematic review conducted with the Cochrane Developmental, Psychosocial and Learning Problems Group. Two reviewers independently assessed studies. Meta-analyses were performed for mortality, illness and side effects.

DATA SOURCES

We searched multiple databases, including CENTRAL and MEDLINE in January 2013. Authors were contacted for missing information.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised trials of preventive zinc supplementation. Hospitalised children and children with chronic diseases were excluded.

RESULTS

80 randomised trials with 205 401 participants were included. There was a small but non-significant effect on all-cause mortality (risk ratio (RR) 0.95 (95% CI 0.86 to 1.05)). Supplementation may reduce incidence of all-cause diarrhoea (RR 0.87 (0.85 to 0.89)), but there was evidence of reporting bias. There was no evidence of an effect of incidence or prevalence of respiratory infections or malaria. There was moderate quality evidence of a very small effect on linear growth (standardised mean difference 0.09 (0.06 to 0.13)) and an increase in vomiting (RR 1.29 (1.14 to 1.46)). There was no evidence of an effect on iron status. Comparing zinc with and without iron cosupplementation and direct comparisons of zinc plus iron versus zinc administered alone favoured cointervention for some outcomes and zinc alone for other outcomes. Effects may be larger for children over 1 year of age, but most differences were not significant.

CONCLUSIONS

Benefits of preventive zinc supplementation may outweigh any potentially adverse effects in areas where risk of zinc deficiency is high. Further research should determine optimal intervention characteristics and delivery strategies.

Prebiotics in healthy infants and children for prevention of acute infectious diseases: a systematic review and meta-analysis

Prebiotics, defined as nondigestible dietary ingredients resistant to gastric acidity and fermented by the intestinal flora, are used to positively influence the composition of intestinal flora, thereby promoting health benefits. The objective of this systematic review was to assess the efficacy of prebiotics in the prevention of acute infectious diseases in children. A systematic literature search was conducted using the Ovid Medline, Scopus, Web of Science, and Cochrane Library's Central databases. Finally, five randomized controlled trials, all of them investigating infants and children 0-24 months of age, were included in the review. Pooled estimates from three studies revealed a statistically significant decrease in the number of infectious episodes requiring antibiotic therapy in the prebiotic group as compared with the placebo group (rate ratio 0.68; 95% confidence interval 0.61-0.77). Studies available indicate that prebiotics may also be effective in decreasing the rate of overall infections in infants and children 0-24 months of age. Further studies in the age group 3-18 years are required to determine whether prebiotics can be considered for the prevention of acute infectious diseases in the older pediatric population.

Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years of age

BACKGROUND

Zinc deficiency is prevalent in low- and middle-income countries, and contributes to significant diarrhoea-, pneumonia-, and malaria-related morbidity and mortality among young children. Zinc deficiency also impairs growth.

OBJECTIVES

To assess the effects of zinc supplementation for preventing mortality and morbidity, and for promoting growth, in children aged six months to 12 years of age.

SEARCH METHODS

Between December 2012 and January 2013, we searched CENTRAL, MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, Embase, African Index Medicus, Conference Proceedings Citation Index, Dissertation Abstracts, Global Health, IndMED, LILACS, WHOLIS, metaRegister of Controlled Trials, and WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials of preventive zinc supplementation in children aged six months to 12 years compared with no intervention, a placebo, or a waiting list control. We excluded hospitalised children and children with chronic diseases or conditions. We excluded food fortification or intake, sprinkles, and therapeutic interventions.

DATA COLLECTION AND ANALYSIS

Two authors screened studies, extracted data, and assessed risk of bias. We contacted trial authors for missing information.

MAIN RESULTS

We included 80 randomised controlled trials with 205,401 eligible participants. We did not consider that the evidence for the key analyses of morbidity and mortality outcomes were affected by risk of bias. The risk ratio (RR) for all-cause mortality was compatible with a reduction and a small increased risk of death with zinc supplementation (RR 0.95, 95% confidence interval (CI) 0.86 to 1.05, 14 studies, high-quality evidence), and also for cause-specific mortality due to diarrhoea (RR 0.95, 95% CI 0.69 to 1.31, four studies, moderate-quality evidence), lower respiratory tract infection (LRTI) (RR 0.86, 95% CI 0.64 to 1.15, three studies, moderate-quality evidence), or malaria (RR 0.90, 95% CI 0.77 to 1.06, two studies, moderate-quality evidence).Supplementation reduced diarrhoea morbidity, including the incidence of all-cause diarrhoea (RR 0.87, 95% CI 0.85 to 0.89, 26 studies, moderate-quality evidence), but the results for LRTI and malaria were imprecise: LRTI (RR 1, 95% CI 0.94 to 1.07, 12 studies, moderate-quality evidence); malaria (RR 1.05, 95% 0.95 to 1.15, four studies, moderate-quality evidence).There was moderate-quality evidence of a very small improvement in height with supplementation (standardised mean difference (SMD) -0.09, 95% CI -0.13 to -0.06; 50 studies), but the size of this effect might not be clinically important. There was a medium to large positive effect on zinc status.Supplementation was associated with an increase in the number of participants with at least one vomiting episode (RR 1.29, 95% CI 1.14 to 1.46, five studies, high-quality evidence). We found no clear evidence of benefit or harm of supplementation with regard to haemoglobin or iron status. Supplementation had a negative effect on copper status.

AUTHORS' CONCLUSIONS

In our opinion, the benefits of preventive zinc supplementation outweigh the harms in areas where the risk of zinc deficiency is relatively high. Further research should determine optimal intervention characteristics such as supplement dose.

Renal improvement by zinc in diabetic mice is associated with glucose metabolism signaling mediated by metallothionein and Akt, but not Akt2

Human epidemiological and animal studies have shown the beneficial effect of zinc supplementation on mitigating diabetic nephropathy. However, the mechanism by which zinc protects the kidney from diabetes remains unknown. Here we demonstrate the therapeutic effects of zinc on diabetes-induced renal pathological and functional changes. These abnormalities were found in both transgenic OVE26 and Akt2-KO diabetic mouse models, accompanied by significant changes in glucose-metabolism-related regulators. The changes included significantly decreased phosphorylation of Akt and GSK-3β, increased phosphorylation of renal glycogen synthase, decreased expression of hexokinase II and PGC-1α, and increased expression of the Akt negative regulators PTEN, PTP1B, and TRB3. All of these were significantly prevented by zinc treatment for 3 months. Furthermore, zinc-stimulated changes in glucose metabolism mediated by Akt were actually found to be metallothionein dependent, but not Akt2 dependent. These results suggest that the therapeutic effects of zinc in diabetic nephropathy are mediated, in part, by the preservation of glucose-metabolism-related pathways via the prevention of diabetes-induced upregulation of Akt negative regulators. Given that zinc deficiency is very common in diabetics, this finding implies that regularly monitoring zinc levels in diabetic patients, as well as supplementing if low, is important in mitigating the development of diabetic nephropathy.

Zinc as an adjunct to the treatment of severe pneumonia in Ecuadorian children: a randomized controlled trial

BACKGROUND

Studies of zinc as an adjunct to treatment of severe pneumonia in children have shown mixed results, possibly because of poor information on zinc status and respiratory pathogens.

OBJECTIVE

We evaluated the effect of zinc given with standard antimicrobial treatment on the duration of respiratory signs in children with severe pneumonia. Zinc status and pathogens were assessed.

DESIGN

Children aged 2-59 mo with severe pneumonia who were admitted to the main children's hospital in Quito, Ecuador, were given standard antibiotics and randomly allocated to receive zinc supplements twice daily or a placebo. Measurements included anthropometric variables, breastfeeding, hemoglobin, plasma zinc, and common bacteria/viral respiratory pathogens. The primary outcome was time to resolution of respiratory signs. The secondary outcome was treatment failure.

RESULTS

We enrolled 225 children in each group. There was no difference between groups in time to resolution of respiratory signs or treatment failure; pathogens were not associated with outcomes. Tachypnea and hypoxemia resolved faster in older children (P = 0.0001) than in younger ones. Higher basal zinc concentration (P = 0.011) and better height-for-age z score (HAZ) (P = 0.044) were associated with faster resolution of chest indrawing. Better weight-for-height z score (WHZ) (P = 0.031) and HAZ (P = 0.048) were associated with faster resolution of tachypnea. Increased C-reactive protein was associated with a longer duration of tachypnea (P = 0.044).

CONCLUSIONS

Zinc did not affect time to pneumonia resolution or treatment failure, nor did type of respiratory pathogens affect outcomes. Higher basal zinc and better HAZ and WHZ were associated with reduced time to resolution of respiratory signs. These results suggest the need for prevention of chronic zinc deficiency and improvement of general nutritional status among Ecuadorian children.

Manganese acquisition and homeostasis at the host-pathogen interface

Pathogenic bacteria acquire transition metals for cell viability and persistence of infection in competition with host nutritional defenses. The human host employs a variety of mechanisms to stress the invading pathogen with both cytotoxic metal ions and oxidative and nitrosative insults while withholding essential transition metals from the bacterium. For example, the S100 family protein calprotectin (CP) found in neutrophils is a calcium-activated chelator of extracellular Mn and Zn and is found in tissue abscesses at sites of infection by Staphylococcus aureus. In an adaptive response, bacteria have evolved systems to acquire the metals in the face of this competition while effluxing excess or toxic metals to maintain a bioavailability of transition metals that is consistent with a particular inorganic "fingerprint" under the prevailing conditions. This review highlights recent biological, chemical and structural studies focused on manganese (Mn) acquisition and homeostasis and connects this process to oxidative stress resistance and iron (Fe) availability that operates at the human host-pathogen interface.

Better drug therapy for the children of Africa: current impediments to success and potential strategies for improvement

A commentary is presented on the urgent need for a comprehensive effort to improve the practice of pediatric therapeutics in Africa. A call for action is addressed to a variety of practitioners internationally, many of whom possess skills that could be fruitfully applied to the improvement of health outcomes for African children. Successful engagement with the many challenges requires the complementary effort of researchers in basic and clinical pharmacology and toxicology, nurses, pharmacists, physicians, clinical pharmacologists, clinical pharmacists, and political leaders and civil servants. While a comprehensive or systematic review of the relevant literature has not been attempted, the authors have highlighted promising initiatives driven by international agencies and academic networks. Two African perspectives are presented to reinforce the prospect of child health gains that can be achieved through consistent pursuit of optimal therapy for conditions such as respiratory infection, diarrhea, malaria, and HIV/AIDS. There is an imperative for development of north-south and south-south partnerships that will amplify current research efforts and mobilize existing knowledge concerning pediatric drugs. The overall goal is a multidisciplinary commitment to making essential medicines available at the right time, the right place, and in the right formulation for African children from infancy to adolescence.

High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling

Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose), 60 ppm Zn (high dose) or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

Zinc supplementation for improving pregnancy and infant outcome

BACKGROUND

It has been suggested that low serum zinc levels may be associated with suboptimal outcomes of pregnancy such as prolonged labour, atonic postpartum haemorrhage, pregnancy-induced hypertension, preterm labour and post-term pregnancies, although many of these associations have not yet been established.

OBJECTIVES

To assess the effects of zinc supplementation in pregnancy on maternal, fetal, neonatal and infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials of zinc supplementation in pregnancy. We excluded quasi-randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Three review authors applied the study selection criteria, assessed trial quality and extracted data. When necessary, we contacted study authors for additional information.

MAIN RESULTS

We included 20 randomised controlled trials (RCTs) reported in 51 papers involving over 15,000 women and their babies. Trials were generally at low risk of bias. Zinc supplementation resulted in a small but significant reduction in preterm birth (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.76 to 0.97 in 16 RCTs; 16 trials of 7637 women). This was not accompanied by a similar reduction in numbers of babies with low birthweight (RR 0.93, 95% CI 0.78 to 1.12; 14 trials of 5643 women). No significant differences were seen between the zinc and no zinc groups for any of the other primary maternal or neonatal outcomes, except for induction of labour in a single trial. No differing patterns were evident in the subgroups of women with low versus normal zinc and nutrition levels or in women who complied with their treatment versus those who did not.

AUTHORS' CONCLUSIONS

The evidence for a 14% relative reduction in preterm birth for zinc compared with placebo was primarily represented by trials involving women of low income and this has some relevance in areas of high perinatal mortality. There was no convincing evidence that zinc supplementation during pregnancy results in other useful and important benefits. Since the preterm association could well reflect poor nutrition, studies to address ways of improving the overall nutritional status of populations in impoverished areas, rather than focusing on micronutrient and or zinc supplementation in isolation, should be an urgent priority.

Metal ion acquisition in Staphylococcus aureus: overcoming nutritional immunity

Transition metals are essential nutrients to virtually all forms of life, including bacterial pathogens. In Staphylococcus aureus, metal ions participate in diverse biochemical processes such as metabolism, DNA synthesis, regulation of virulence factors, and defense against oxidative stress. As an innate immune response to bacterial infection, vertebrate hosts sequester transition metals in a process that has been termed "nutritional immunity." To successfully infect vertebrates, S. aureus must overcome host sequestration of these critical nutrients. The objective of this review is to outline the current knowledge of staphylococcal metal ion acquisition systems, as well as to define the host mechanisms of nutritional immunity during staphylococcal infection.

A molecular mechanism for bacterial susceptibility to zinc

Transition row metal ions are both essential and toxic to microorganisms. Zinc in excess has significant toxicity to bacteria, and host release of Zn(II) at mucosal surfaces is an important innate defence mechanism. However, the molecular mechanisms by which Zn(II) affords protection have not been defined. We show that in Streptococcus pneumoniae extracellular Zn(II) inhibits the acquisition of the essential metal Mn(II) by competing for binding to the solute binding protein PsaA. We show that, although Mn(II) is the high-affinity substrate for PsaA, Zn(II) can still bind, albeit with a difference in affinity of nearly two orders of magnitude. Despite the difference in metal ion affinities, high-resolution structures of PsaA in complex with Mn(II) or Zn(II) showed almost no difference. However, Zn(II)-PsaA is significantly more thermally stable than Mn(II)-PsaA, suggesting that Zn(II) binding may be irreversible. In vitro growth analyses show that extracellular Zn(II) is able to inhibit Mn(II) intracellular accumulation with little effect on intracellular Zn(II). The phenotype of S. pneumoniae grown at high Zn(II):Mn(II) ratios, i.e. induced Mn(II) starvation, closely mimicked a ΔpsaA mutant, which is unable to accumulate Mn(II). S. pneumoniae infection in vivo elicits massive elevation of the Zn(II):Mn(II) ratio and, in vitro, these Zn(II):Mn(II) ratios inhibited growth due to Mn(II) starvation, resulting in heightened sensitivity to oxidative stress and polymorphonuclear leucocyte killing. These results demonstrate that microbial susceptibility to Zn(II) toxicity is mediated by extracellular cation competition and that this can be harnessed by the innate immune response.

Zinc supplementation as an adjunct to antibiotics in the treatment of pneumonia in children 2 to 59 months of age

BACKGROUND

Diarrhoeal disorders and acute respiratory infections (ARIs), especially pneumonia, are the most common causes of death in low-income countries. Studies evaluating the impact of zinc supplementation as an adjunct in the management of pneumonia are limited and have shown variable results.

OBJECTIVES

To evaluate zinc supplementation, as an adjunct to antibiotics, in the treatment (clinical recovery) of pneumonia in children aged two to 59 months.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), which contains the Cochrane Acute Respiratory Infections (ARI) Group's and the Cochrane Infectious Diseases Group's Specialised Registers, MEDLINE (1950 to March week 2, 2011), EMBASE (1974 to March 2011), CINAHL (1981 to March 2011), LILACS (1985 to March 2011), AMED (1985 to March 2011), CAB Abstracts (1910 to March 2011) and Web of Science (2000 to March 2011).

SELECTION CRITERIA

Randomised control trials (RCTs) evaluating supplementation of zinc as an adjunct to antibiotics for pneumonia in children aged two to 59 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and screened all available titles and abstracts for inclusion. If the relevance could not be ascertained by screening the title and abstract, we retrieved and reviewed the full text of the article.

MAIN RESULTS

We included four trials in which 3267 children aged two to 35 months participated. Analysis showed that zinc supplementation in addition to standard antibiotic therapy in children with severe and non-severe pneumonia failed to show a statistically significant effect on clinical recovery (risk ratio (RR) 1.02; 95% confidence interval (CI) 0.93 to 1.11). Similary, zinc supplementation in children with severe pneumonia, as an adjunct to standard antibiotic therapy, did not show a statistically significant effect on clinical recovery measured as resolution of tachypnoea (respiratory rate > 50 breaths per minute) (RR 1.13; 95% CI 0.82 to 1.57) and cessation of chest indrawing (RR 1.08; 95% CI 0.88 to 1.31) as compared to the control group. Zinc supplementation in children with severe pneumonia also showed a non-significant effect on the duration of hospitalization stay as compared to the control (RR 1.04; 95% CI 0.89 to 1.22).

AUTHORS' CONCLUSIONS

Evidence provided in this review is insufficient to recommend the use of zinc as an adjunct to standard antibiotic therapy for pneumonia in children aged two to 35 months.

Evidence for perinatal and child health care guidelines in crisis settings: can Cochrane help?

BACKGROUND

It is important that healthcare provided in crisis settings is based on the best available research evidence. We reviewed guidelines for child and perinatal health care in crisis situations to determine whether they were based on research evidence, whether Cochrane systematic reviews were available in the clinical areas addressed by these guidelines and whether summaries of these reviews were provided in Evidence Aid.

METHODS

Broad internet searches were undertaken to identify relevant guidelines. Guidelines were appraised using AGREE and the clinical areas that were relevant to perinatal or child health were extracted. We searched The Cochrane Database of Systematic Reviews to identify potentially relevant reviews. For each review we determined how many trials were included, and how many were conducted in resource-limited settings.

RESULTS

Six guidelines met selection criteria. None of the included guidelines were clearly based on research evidence. 198 Cochrane reviews were potentially relevant to the guidelines. These reviews predominantly addressed nutrient supplementation, breastfeeding, malaria, maternal hypertension, premature labour and prevention of HIV transmission. Most reviews included studies from developing settings. However for large portions of the guidelines, particularly health services delivery, there were no relevant reviews. Only 18 (9.1%) reviews have summaries in Evidence Aid.

CONCLUSIONS

We did not identify any evidence-based guidelines for perinatal and child health care in disaster settings. We found many Cochrane reviews that could contribute to the evidence-base supporting future guidelines. However there are important issues to be addressed in terms of the relevance of the available reviews and increasing the number of reviews addressing health care delivery.