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Imdad A, Rogner J, Sherwani RN, Sidhu J, Regan A, Haykal MR, Tsistinas O, Smith A, Chan XHS, Mayo-Wilson E, Bhutta ZA. Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years. Cochrane Database Syst Rev 2023; 3:CD009384. [PMID: 36994923 PMCID: PMC10061962 DOI: 10.1002/14651858.cd009384.pub3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
BACKGROUND Zinc deficiency is prevalent in low- and middle-income countries, and is considered a significant risk factor for morbidity, mortality, and linear growth failure. The effectiveness of preventive zinc supplementation in reducing prevalence of zinc deficiency needs to be assessed. OBJECTIVES To assess the effects of zinc supplementation for preventing mortality and morbidity, and for promoting growth, in children aged 6 months to 12 years. SEARCH METHODS A previous version of this review was published in 2014. In this update, we searched CENTRAL, MEDLINE, Embase, five other databases, and one trials register up to February 2022, together with reference checking and contact with study authors to identify additional studies. SELECTION CRITERIA Randomized controlled trials (RCTs) of preventive zinc supplementation in children aged 6 months to 12 years compared with no intervention, a placebo, or a waiting list control. We excluded hospitalized children and children with chronic diseases or conditions. We excluded food fortification or intake, sprinkles, and therapeutic interventions. DATA COLLECTION AND ANALYSIS Two review authors screened studies, extracted data, and assessed the risk of bias. We contacted study authors for missing information and used GRADE to assess the certainty of evidence. The primary outcomes of this review were all-cause mortality; and cause-specific mortality, due to all-cause diarrhea, lower respiratory tract infection (LRTI, including pneumonia), and malaria. We also collected information on a number of secondary outcomes, such as those related to diarrhea and LRTI morbidity, growth outcomes and serum levels of micronutrients, and adverse events. MAIN RESULTS We included 16 new studies in this review, resulting in a total of 96 RCTs with 219,584 eligible participants. The included studies were conducted in 34 countries; 87 of them in low- or middle-income countries. Most of the children included in this review were under five years of age. The intervention was delivered most commonly in the form of syrup as zinc sulfate, and the most common dose was between 10 mg and 15 mg daily. The median duration of follow-up was 26 weeks. We did not consider that the evidence for the key analyses of morbidity and mortality outcomes was affected by risk of bias. High-certainty evidence showed little to no difference in all-cause mortality with preventive zinc supplementation compared to no zinc (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.84 to 1.03; 16 studies, 17 comparisons, 143,474 participants). Moderate-certainty evidence showed that preventive zinc supplementation compared to no zinc likely results in little to no difference in mortality due to all-cause diarrhea (RR 0.95, 95% CI 0.69 to 1.31; 4 studies, 132,321 participants); but probably reduces mortality due to LRTI (RR 0.86, 95% CI 0.64 to 1.15; 3 studies, 132,063 participants) and mortality due to malaria (RR 0.90, 95% CI 0.77 to 1.06; 2 studies, 42,818 participants); however, the confidence intervals around the summary estimates for these outcomes were wide, and we could not rule out a possibility of increased risk of mortality. Preventive zinc supplementation likely reduces the incidence of all-cause diarrhea (RR 0.91, 95% CI 0.90 to 0.93; 39 studies, 19,468 participants; moderate-certainty evidence) but results in little to no difference in morbidity due to LRTI (RR 1.01, 95% CI 0.95 to 1.08; 19 studies, 10,555 participants; high-certainty evidence) compared to no zinc. There was moderate-certainty evidence that preventive zinc supplementation likely leads to a slight increase in height (standardized mean difference (SMD) 0.12, 95% CI 0.09 to 0.14; 74 studies, 20,720 participants). Zinc 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; 5 studies, 35,192 participants; high-certainty evidence). We report a number of other outcomes, including the effect of zinc supplementation on weight and serum markers such as zinc, hemoglobin, iron, copper, etc. We also performed a number of subgroup analyses and there was a consistent finding for a number of outcomes that co-supplementation of zinc with iron decreased the beneficial effect of zinc. AUTHORS' CONCLUSIONS Even though we included 16 new studies in this update, the overall conclusions of the review remain unchanged. Zinc supplementation might help prevent episodes of diarrhea and improve growth slightly, particularly in children aged 6 months to 12 years of age. The benefits of preventive zinc supplementation may outweigh the harms in regions where the risk of zinc deficiency is relatively high.
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Affiliation(s)
- Aamer Imdad
- Department of Pediatrics, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Jaimie Rogner
- Departments of Medicine and Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Rida N Sherwani
- Department of Pediatrics, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Jasleen Sidhu
- Norton College of Medicine, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Allison Regan
- Norton College of Medicine, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Maya R Haykal
- Norton College of Medicine, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Olivia Tsistinas
- Health Sciences Library, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Abigail Smith
- Health Sciences Library, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Xin Hui S Chan
- Pandemic Sciences Institute, University of Oxford, Oxford, UK
| | - Evan Mayo-Wilson
- Department of Epidemiology, UNC Gillings School of Global Public HealthMcGavran-Greenberg Hall, Chapel Hill, NC, USA
| | - Zulfiqar A Bhutta
- Centre for Global Child Health, The Hospital for SickKids, Toronto, Canada
- Center of Excellence for Women and Child Health, Aga Khan University, Karachi, Pakistan
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Smith HC, German E, Ferreira DM, Rylance J. Nasopharyngeal colonisation with Streptococcus pneumoniae in malnourished children: a systematic review and meta-analysis of prevalence. Trans R Soc Trop Med Hyg 2020; 113:227-233. [PMID: 30624761 DOI: 10.1093/trstmh/try139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/03/2018] [Accepted: 12/25/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is an intermittent commensal organism in the nasopharynx. Colonisation is a prerequisite for disease and malnourished children are especially susceptible to severe infection. This systematic review examines published prevalence rates of pneumococcal colonisation in the upper respiratory tract of chronically malnourished children <5 y of age. METHODS A systematic literature search was performed using MEDLINE, PubMed, Web of Science and Scopus. After screening, relevant studies were assessed for quality using Strengthening the Reporting of Observational Studies in Epidemiology criteria. Colonisation data were extracted and a random effects model was used to pool prevalence estimates. RESULTS Nine studies were included. The prevalence rate of S. pneumoniae colonisation in malnourished children during the first month of life ranged from 1.0 to 2.0%, increasing at 2 mo to 53.9-80.0%. Carriage remained similar from 3 to 60 mo at 64.1-88.0%. Meta-analysis showed a pooled prevalence of 67.2% in infants 0-3 mo of age (95% confidence interval [CI] 55.6 to 78.7), 77.9% in infants 3-6 mo of age (95% CI 68.1 to 87.7) and 77.8% in infants 6-60 mo of age (95% CI 73.9-81.6%). CONCLUSIONS In malnourished children, it is plausible that rates of pneumococcal colonisation are higher than in healthy, well-nourished children. Knowledge of colonisation rates can inform policies on vaccination and ancillary interventions during treatment of malnutrition. Future studies should assess the impact of reducing colonisation on disease rates or transmission in these 'at-risk' individuals.
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Affiliation(s)
- Holly C Smith
- School of Medicine, University of Liverpool, Ashton Street, Liverpool, UK
| | - Esther German
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Daniela M Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Jamie Rylance
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.,Malawi-Liverpool-Wellcome Programme, Chichiri, Blantyre, Malawi
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Skalny AV, Rink L, Ajsuvakova OP, Aschner M, Gritsenko VA, Alekseenko SI, Svistunov AA, Petrakis D, Spandidos DA, Aaseth J, Tsatsakis A, Tinkov AA. Zinc and respiratory tract infections: Perspectives for COVID‑19 (Review). Int J Mol Med 2020; 46:17-26. [PMID: 32319538 PMCID: PMC7255455 DOI: 10.3892/ijmm.2020.4575] [Citation(s) in RCA: 211] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/13/2020] [Indexed: 01/08/2023] Open
Abstract
In view of the emerging COVID‑19 pandemic caused by SARS‑CoV‑2 virus, the search for potential protective and therapeutic antiviral strategies is of particular and urgent interest. Zinc is known to modulate antiviral and antibacterial immunity and regulate inflammatory response. Despite the lack of clinical data, certain indications suggest that modulation of zinc status may be beneficial in COVID‑19. In vitro experiments demonstrate that Zn2+ possesses antiviral activity through inhibition of SARS‑CoV RNA polymerase. This effect may underlie therapeutic efficiency of chloroquine known to act as zinc ionophore. Indirect evidence also indicates that Zn2+ may decrease the activity of angiotensin‑converting enzyme 2 (ACE2), known to be the receptor for SARS‑CoV‑2. Improved antiviral immunity by zinc may also occur through up‑regulation of interferon α production and increasing its antiviral activity. Zinc possesses anti‑inflammatory activity by inhibiting NF‑κB signaling and modulation of regulatory T‑cell functions that may limit the cytokine storm in COVID‑19. Improved Zn status may also reduce the risk of bacterial co‑infection by improving mucociliary clearance and barrier function of the respiratory epithelium, as well as direct antibacterial effects against S. pneumoniae. Zinc status is also tightly associated with risk factors for severe COVID‑19 including ageing, immune deficiency, obesity, diabetes, and atherosclerosis, since these are known risk groups for zinc deficiency. Therefore, Zn may possess protective effect as preventive and adjuvant therapy of COVID‑19 through reducing inflammation, improvement of mucociliary clearance, prevention of ventilator‑induced lung injury, modulation of antiviral and antibacterial immunity. However, further clinical and experimental studies are required.
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Affiliation(s)
- Anatoly V. Skalny
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
- Yaroslavl State University, 150003 Yaroslavl, Russia
| | - Lothar Rink
- Institute of Immunology, Medical Faculty, RWTH Aachen University, D-52062 Aachen, Germany
| | - Olga P. Ajsuvakova
- Yaroslavl State University, 150003 Yaroslavl, Russia
- Federal Research Centre of Biological Systems and Agro-technologies of the Russian Academy of Sciences, 460000 Orenburg, Russia
| | - Michael Aschner
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Viktor A. Gritsenko
- Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, 460000 Orenburg
| | - Svetlana I. Alekseenko
- I.I. Mechnikov North-Western State Medical University, 191015 St. Petersburg
- K.A. Rauhfus Children's City Multidisciplinary Clinical Center for High Medical Technologies, 191000 St. Petersburg, Russia
| | - Andrey A. Svistunov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
| | | | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, Medical School, University of Crete, 71409 Heraklion, Greece
| | - Jan Aaseth
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
- Research Department, Innlandet Hospital Trust, 3159894 Brumunddal, Norway
| | - Aristidis Tsatsakis
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
- Center of Toxicology Science and Research
| | - Alexey A. Tinkov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow
- Yaroslavl State University, 150003 Yaroslavl, Russia
- Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, 460000 Orenburg
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Lassi ZS, Kurji J, Oliveira CSD, Moin A, Bhutta ZA. Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age. Cochrane Database Syst Rev 2020; 4:CD010205. [PMID: 32266964 PMCID: PMC7140593 DOI: 10.1002/14651858.cd010205.pub2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Zinc is a vital micronutrient for humans and is essential for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can lead to slower physical, cognitive and sexual growth, cause skin disorders, decrease immunity, increase incidence of acute illnesses in infants and children and contribute to childhood stunting. By estimation, 17.3% of the world population is at risk of inadequate zinc intake. Such nutritional impairment increases the risk of diarrhoea and pneumonia by 20%, as well as leads to a global loss of more than 16 million disability-adjusted life years in children less than five years of age. Not only does zinc deficiency affect lives, it adds to the considerable financial burden on depleted resources in countries that are most affected. By preventing or curing this deficiency, we can improve childhood mortality, morbidity and growth. OBJECTIVES To assess the effectiveness of zinc supplementation for the promotion of growth, reduction in mortality, and the prevention of infections in infants less than six months of age. SEARCH METHODS We used the standard search strategy of the Cochrane Neonatal Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 4), MEDLINE via PubMed (1966 to 18 May 2018), Embase (1980 to 18 May 2018), and CINAHL (1982 to 18 May 2018). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. An updated search from 1 January 2018 to 29 January 2020 was run in the following databases: CENTRAL via CRS Web, MEDLINE via Ovid, and CINAHL via EBSCOhost. SELECTION CRITERIA All randomised controlled (individual and cluster randomised) and quasi-randomised trials of zinc supplementation in healthy, term infants, less than six months of age comparing infant mortality, incidence of diarrhoea or respiratory illnesses, growth and/or serum zinc levels were eligible. DATA COLLECTION AND ANALYSIS Two review authors screened search results (title and abstracts) and relevant full texts. Studies fulfilling prespecified inclusion criteria were included with any disagreements resolved by consensus. Extraction and analysis were then conducted. We used the GRADE approach to assess the quality of evidence as indicated by certainty in effect estimates. MAIN RESULTS Eight studies (with 85,629 infants) were included and five studies were meta-analysed, out of which four studies compared zinc with placebo, and one compared zinc plus riboflavin versus riboflavin. Certain growth outcomes after six months of intervention (Weight for Age Z-scores (WAZ) (standardised mean difference) (SMD) 0.16, 95% CI 0.03 to 0.29; three studies, n = 955; fixed-effect; heterogeneity Chi² P = 0.96); I² = 0%); change in WAZ (SMD 0.16, 95% CI 0.07 to 0.25; one study, n = 386; fixed-effect); (Weight-for-Length Z-score (WLZ) (SMD 0.15, 95% CI 0.02 to 0.28; three studies, n = 955; fixed-effect; heterogeneity: Chi² P = 0.81); I² = 0%); (change in WLZ (SMD 0.17, 95% CI 0.06 to 0.28; one study, n = 386; fixed-effect)) were positively affected by zinc supplementation compared to placebo. A single study reported no difference in the incidence of diarrhoea and lower respiratory tract infection with zinc supplementation. Zinc had no effect on mortality in children younger than 12 months. When zinc plus riboflavin was compared to riboflavin only, significant improvement was observed in the incidence of wasting at 24 months (risk ratio (RR) 0.59, 95% CI 0.37 to 0.96; one study, n = 296; fixed-effect), but significant worsening of incidence of stunting was present at 21 months (RR 1.53, 95% CI 1.09 to 2.16; one study, n = 298; fixed-effect). AUTHORS' CONCLUSIONS There was a significant positive impact of zinc supplementation on WAZ and WLZ after six months of intervention in infants compared to placebo. When a combined supplement of zinc and riboflavin was compared to riboflavin, there was a significant reduction in wasting at 24 months, but stunting at 21 months was negatively affected. Although included trials were of good-to-moderate quality, evidence that could be meta-analysed was based on a few studies which affected the overall quality of results. Regardless, there is a need for strong trials conducted in infants younger than six months before a strong recommendation can be made supporting zinc supplementation in this age group.
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Affiliation(s)
- Zohra S Lassi
- University of AdelaideRobinson Research InstituteAdelaideAustraliaAustralia
| | - Jaameeta Kurji
- University of OttawaSchool of Epidemiology and Public HealthOttawaCanada
| | | | - Anoosh Moin
- Aga Khan University HospitalDivision of Women and Child HealthStadium RoadPO Box 3500KarachiPakistan74800
| | - Zulfiqar A Bhutta
- The Hospital for Sick ChildrenCentre for Global Child HealthTorontoCanada
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Rerksuppaphol S, Rerksuppaphol L. A randomized controlled trial of zinc supplementation in the treatment of acute respiratory tract infection in Thai children. Pediatr Rep 2019; 11:7954. [PMID: 31214301 PMCID: PMC6548996 DOI: 10.4081/pr.2019.7954] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/08/2019] [Indexed: 01/27/2023] Open
Abstract
Acute Lower Respiratory Tract Infections (ALRI) are one of the most common causes of morbidity and mortality in young children. Zinc supplementation has been shown to have a preventive effect against respiratory infections, but little evidence is available on its effect on the treatment of ALRI. This study examined the effect of zinc supplementation on the treatment outcome in children that were hospitalized with ALRI. A randomized, doubleblinded, placebo-controlled trial was conducted on 64 hospitalized children with ALRI, who were aged between 2 and 60 months. Children were randomly allocated to receive zinc (30 mg elemental zinc/day) or placebo. The primary outcome was the time to the cessation of ALRI, while the secondary outcomes were the length of the stay in hospital and the individual features of the disease. The study found that ALRI cessation was faster in children who received zinc supplementation (median (IQR): 3 (2-4) days and 4 (3-5) days, respectively; P=0.008), and that their hospital stay was shorter (mean (SD): 3.8 (1.3) days and 6.1 (3.2) days, respectively; P<0.001) than the placebo group. Zinc supplementation was well-tolerated, and no adverse events were reported. In conclusion, zinc supplementation reduced the number of days of ALRI in Thai children, as well as their stay in hospital.
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Affiliation(s)
| | - Lakkana Rerksuppaphol
- Department of Preventive Medicine, Faculty of Medicine, Srinakharinwirot University, Thailand
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Weiser JN, Ferreira DM, Paton JC. Streptococcus pneumoniae: transmission, colonization and invasion. Nat Rev Microbiol 2018; 16:355-367. [PMID: 29599457 PMCID: PMC5949087 DOI: 10.1038/s41579-018-0001-8] [Citation(s) in RCA: 521] [Impact Index Per Article: 86.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Streptococcus pneumoniae has a complex relationship with its obligate human host. On the one hand, the pneumococci are highly adapted commensals, and their main reservoir on the mucosal surface of the upper airways of carriers enables transmission. On the other hand, they can cause severe disease when bacterial and host factors allow them to invade essentially sterile sites, such as the middle ear spaces, lungs, bloodstream and meninges. Transmission, colonization and invasion depend on the remarkable ability of S. pneumoniae to evade or take advantage of the host inflammatory and immune responses. The different stages of pneumococcal carriage and disease have been investigated in detail in animal models and, more recently, in experimental human infection. Furthermore, widespread vaccination and the resulting immune pressure have shed light on pneumococcal population dynamics and pathogenesis. Here, we review the mechanistic insights provided by these studies on the multiple and varied interactions of the pneumococcus and its host.
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Djoko KY, Ong CLY, Walker MJ, McEwan AG. The Role of Copper and Zinc Toxicity in Innate Immune Defense against Bacterial Pathogens. J Biol Chem 2015; 290:18954-61. [PMID: 26055706 DOI: 10.1074/jbc.r115.647099] [Citation(s) in RCA: 251] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Zinc (Zn) and copper (Cu) are essential for optimal innate immune function, and nutritional deficiency in either metal leads to increased susceptibility to bacterial infection. Recently, the decreased survival of bacterial pathogens with impaired Cu and/or Zn detoxification systems in phagocytes and animal models of infection has been reported. Consequently, a model has emerged in which the host utilizes Cu and/or Zn intoxication to reduce the intracellular survival of pathogens. This review describes and assesses the potential role for Cu and Zn intoxication in innate immune function and their direct bactericidal function.
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Affiliation(s)
- Karrera Y Djoko
- From the School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Cheryl-lynn Y Ong
- From the School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Mark J Walker
- From the School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Alastair G McEwan
- From the School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia
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Multi-serotype pneumococcal nasopharyngeal carriage prevalence in vaccine naïve Nepalese children, assessed using molecular serotyping. PLoS One 2015; 10:e0114286. [PMID: 25643355 PMCID: PMC4313945 DOI: 10.1371/journal.pone.0114286] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 11/05/2014] [Indexed: 12/20/2022] Open
Abstract
Invasive pneumococcal disease is one of the major causes of death in young children in resource poor countries. Nasopharyngeal carriage studies provide insight into the local prevalence of circulating pneumococcal serotypes. There are very few data on the concurrent carriage of multiple pneumococcal serotypes. This study aimed to identify the prevalence and serotype distribution of pneumococci carried in the nasopharynx of young healthy Nepalese children prior to the introduction of a pneumococcal conjugate vaccine using a microarray-based molecular serotyping method capable of detecting multi-serotype carriage. We conducted a cross-sectional study of healthy children aged 6 weeks to 24 months from the Kathmandu Valley, Nepal between May and October 2012. Nasopharyngeal swabs were frozen and subsequently plated on selective culture media. DNA extracts of plate sweeps of pneumococcal colonies from these cultures were analysed using a molecular serotyping microarray capable of detecting relative abundance of multiple pneumococcal serotypes. 600 children were enrolled into the study: 199 aged 6 weeks to <6 months, 202 aged 6 months to < 12 months, and 199 aged 12 month to 24 months. Typeable pneumococci were identified in 297/600 (49·5%) of samples with more than one serotype being found in 67/297 (20·2%) of these samples. The serotypes covered by the thirteen-valent pneumococcal conjugate vaccine were identified in 44·4% of samples containing typeable pneumococci. Application of a molecular serotyping approach to identification of multiple pneumococcal carriage demonstrates a substantial prevalence of co-colonisation. Continued surveillance utilising this approach following the introduction of routine use of pneumococcal conjugate vaccinates in infants will provide a more accurate understanding of vaccine efficacy against carriage and a better understanding of the dynamics of subsequent serotype and genotype replacement.
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Adegbola RA, DeAntonio R, Hill PC, Roca A, Usuf E, Hoet B, Greenwood BM. Carriage of Streptococcus pneumoniae and other respiratory bacterial pathogens in low and lower-middle income countries: a systematic review and meta-analysis. PLoS One 2014; 9:e103293. [PMID: 25084351 PMCID: PMC4118866 DOI: 10.1371/journal.pone.0103293] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/27/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs) are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact. METHODS AND FINDINGS We have systematically reviewed published studies reporting nasopharyngeal or oropharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Neisseria meningitidis in children and adults in low and lower-middle income countries. Studies reporting pneumococcal carriage for healthy children <5 years of age were selected for a meta-analysis. The prevalences of carriage for S. pneumoniae, H. influenzae, and M. catarrhalis were generally higher in low income than in lower-middle income countries and were higher in young children than in adults. The prevalence of S. aureus was high in neonates. Meta-analysis of data from young children before the introduction of PCVs showed a pooled prevalence estimate of 64.8% (95% confidence interval, 49.8%-76.1%) in low income countries and 47.8% (95% confidence interval, 44.7%-50.8%) in lower-middle income countries. The most frequent serotypes were 6A, 6B, 19A, 19F, and 23F. CONCLUSIONS In low and lower-middle income countries, pneumococcal carriage is frequent, especially in children, and the spectrum of serotypes is wide. However, because data are limited, additional studies are needed to adequately assess the impact of PCV introduction on carriage of respiratory bacteria in these countries.
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Affiliation(s)
| | | | - Philip C. Hill
- Medical Research Council Unit, Banjul, The Gambia
- Centre for International Health, School of Medicine, University of Otago, Dunedin, New Zealand
| | - Anna Roca
- Medical Research Council Unit, Banjul, The Gambia
| | - Effua Usuf
- Medical Research Council Unit, Banjul, The Gambia
| | | | - Brian M. Greenwood
- Faculty of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Abstract
BACKGROUND Otitis media is inflammation of the middle ear and is usually caused by infection. It affects people of all ages but is particularly common in young children. Around 164 million people worldwide have long-term hearing loss caused by this condition, 90% of them in low-income countries. As zinc supplements prevent pneumonia in disadvantaged children, we wanted to investigate whether zinc supplements could also prevent otitis media. OBJECTIVES To evaluate whether zinc supplements prevent otitis media in adults and children of different ages. SEARCH METHODS We searched CENTRAL (2014, Issue 1), MEDLINE (1950 to February week 4, 2014) and EMBASE (1974 to March 2014). SELECTION CRITERIA Randomised, placebo-controlled trials of zinc supplements given at least once a week for at least a month for preventing otitis media. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the eligibility and methodological quality of the included trials and extracted and analysed data. We summarised results using risk ratios (RRs) or rate ratios for dichotomous data and mean differences (MDs) for continuous data. We combined trial results where appropriate. MAIN RESULTS No new trials were identified for inclusion in this update. We identified 12 trials for inclusion, 10 of which contributed outcomes data. There were a total of 6820 participants. In trials of healthy children living in low-income communities, two trials did not demonstrate a significant difference between the zinc-supplemented and placebo groups in the numbers of participants experiencing an episode of definite otitis media during follow-up (3191 participants); another trial showed a significantly lower incidence rate of otitis media in the zinc group (rate ratio 0.69, 95% confidence interval (CI) 0.61 to 0.79, n = 1621). A small trial of 39 infants undergoing treatment for severe malnutrition suggested a benefit of zinc for the mean number of episodes of otitis media (mean difference (MD) -1.12 episodes, 95% CI -2.21 to -0.03). Zinc supplements did not seem to cause any serious adverse events but a small minority of children were reported to have vomited shortly after ingestion of the supplements. The trial evidence included is generally of good quality, with a low risk of bias. AUTHORS' CONCLUSIONS Evidence on whether zinc supplementation can reduce the incidence of otitis media in healthy children under the age of five years living in low- and middle-income countries is mixed. There is some evidence of benefit in children being treated for marasmus (severe malnutrition), but this is based on one small trial and should therefore be treated with caution.
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Affiliation(s)
- Anjana Gulani
- Max Multispeciality CentreDepartment of PediatricsN‐110, Panchsheel ParkNew DelhiIndia110017
- Max Superspeciality HospitalDepartment of Pediatrics and NeonatologySaketNew DelhiIndia
| | - Harshpal S Sachdev
- Sitaram Bhartia Institute of Science and ResearchDepartment of Pediatrics and Clinical EpidemiologyB‐16 Qutab Institutional AreaNew DelhiIndia110016
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Mayo-Wilson E, Junior JA, Imdad A, Dean S, Chan XHS, Chan ES, Jaswal A, Bhutta ZA. Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years of age. Cochrane Database Syst Rev 2014:CD009384. [PMID: 24826920 DOI: 10.1002/14651858.cd009384.pub2] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
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.
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Affiliation(s)
- Evan Mayo-Wilson
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore MD, MD, USA, 21205
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Shafeeq S, Kuipers OP, Kloosterman TG. The role of zinc in the interplay between pathogenic streptococci and their hosts. Mol Microbiol 2013; 88:1047-57. [DOI: 10.1111/mmi.12256] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2013] [Indexed: 12/26/2022]
Affiliation(s)
- Sulman Shafeeq
- Department of Molecular Genetics; Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 7; 9747 AG; Groningen; the Netherlands
| | - Oscar P. Kuipers
- Department of Molecular Genetics; Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 7; 9747 AG; Groningen; the Netherlands
| | - Tomas G. Kloosterman
- Department of Molecular Genetics; Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; Nijenborgh 7; 9747 AG; Groningen; the Netherlands
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Abstract
BACKGROUND Otitis media (OM) is inflammation of the middle ear and is usually caused by infection. It affects people of all ages but is particularly common in young children. Around 164 million people worldwide have long-term hearing loss caused by this condition, 90% of them in low-income countries. As zinc supplements prevent pneumonia in disadvantaged children, we wanted to investigate whether zinc supplements could also prevent OM. OBJECTIVES To evaluate whether zinc supplements prevent OM in adults and children of different ages. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 1) which includes the Cochrane Acute Respiratory Infections Groups' Specialised Register, MEDLINE (1950 to February week 1, 2012) and EMBASE (1974 to February 2012). SELECTION CRITERIA Randomised, placebo-controlled trials of zinc supplements given at least once a week for at least a month for preventing OM. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the eligibility and methodological quality of the included trials and extracted and analysed data. We summarised results using risk ratios (RRs) or rate ratios for dichotomous data and mean differences (MDs) for continuous data. We combined trial results where appropriate. MAIN RESULTS We identified 12 trials for inclusion, 10 of which contributed outcomes data. There was a total of 6820 participants. In trials of healthy children living in low-income communities, two trials did not demonstrate a significant difference between the zinc supplemented and placebo groups in the numbers of participants experiencing an episode of definite OM during follow-up (3191 participants); another trial showed a significantly lower incidence rate of OM in the zinc group (rate ratio 0.69, 95% confidence interval (CI) 0.61 to 0.79, n = 1621). A small trial of 39 infants undergoing treatment for severe malnutrition suggested a benefit of zinc for the mean number of episodes of OM (mean difference (MD) -1.12 episodes, 95% CI -2.21 to -0.03). Zinc supplements did not seem to cause any serious adverse events but a small minority of children were reported to have vomited shortly after ingestion of the supplements. The trial evidence included is generally of good quality, with a low risk of bias. AUTHORS' CONCLUSIONS Evidence on whether zinc supplementation can reduce the incidence of OM in healthy children under the age of five years living in low- and middle-income countries is mixed. There is some evidence of benefit in children being treated for marasmus (severe malnutrition) but this is based on one small trial and should therefore be treated with caution.
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Affiliation(s)
- Anjana Gulani
- Department of Pediatrics and Clinical Epidemiology, Sitaram Bhartia Institute of Science and Research, New Delhi, India.
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Glennie SJ, Williams NA, Heyderman RS. Mucosal immunity in resource-limited setting: is the battle ground different? Trends Microbiol 2010; 18:487-93. [PMID: 20832319 DOI: 10.1016/j.tim.2010.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/29/2010] [Accepted: 08/06/2010] [Indexed: 01/28/2023]
Abstract
In many developing countries, populations are under considerable pressure from high bacterial exposure on mucosal surfaces. Immune dysregulation in this setting is multifactorial and is driven by a range of environmental factors, undernutrition and coinfections such as measles, malaria and HIV. Disruption or subversion of respiratory-tract and intestinal epithelial barriers leads to increased invasion by mucosal pathogens and a high frequency of life-threatening bacterial disease. It is our opinion that a process of epithelial barrier dysfunction and immune dysregulation at these mucosal surfaces leads to the much higher rates of pneumonia, meningitis and severe sepsis seen in resource-limited countries.
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Affiliation(s)
- Sarah J Glennie
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
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Marchisio P, Esposito S, Bianchini S, Desantis C, Galeone C, Nazzari E, Pignataro L, Principi N. Effectiveness of a propolis and zinc solution in preventing acute otitis media in children with a history of recurrent acute otitis media. Int J Immunopathol Pharmacol 2010; 23:567-75. [PMID: 20646352 DOI: 10.1177/039463201002300219] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Recurrent acute otitis media (rAOM) is frequently encountered in infants and children and the lack of any definitive treatment has led parents and physicians to try complementary and alternative therapies. We evaluated the efficacy of a propolis and zinc suspension in preventing AOM in 122 children aged 1-5 years with a documented history of rAOM, who were prospectively, blindly, randomized 1:1 to receive the suspension plus elimination of environmental risk factors or elimination of environmental risk factors only. AOM- and respiratory-related morbidity were assessed at study entry and every four weeks. In the 3-month treatment period AOM was diagnosed in 31 (50.8%) children given the propolis and zinc suspension and in 43 (70.5%) controls (p=0.04). The mean number of episodes of AOM per child/month was 0.23+/-0.26 in the propolis and zinc group and 0.34+/-0.29 in controls (reduction 32.0%, p=0.03). The administration of a propolis and zinc suspension to children with a history of rAOM can significantly reduce the risk of new AOM episodes and AOM-related antibiotic courses, with no problem of safety or tolerability, and with a very good degree of parental satisfaction. No effect can be expected on respiratory infections other than AOM.
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Affiliation(s)
- P Marchisio
- Department of Maternal and Pediatric Sciences, University of Milan, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
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Abstract
BACKGROUND Otitis media (inflammation of the middle ear, usually caused by infection) affects people of all ages, but is particularly common in young children. Around 164 million people worldwide have long-term hearing loss caused by this condition, 90% of them in low-income countries. Because zinc supplements prevent pneumonia in disadvantaged children, we wondered whether they prevent otitis media. OBJECTIVES To evaluate whether zinc supplements prevent otitis media in adults and children of different ages. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2) which includes the Acute Respiratory Infection Groups' Specialised Register; MEDLINE (1950 to June Week 1 2009); and EMBASE (1974 to June 2009). SELECTION CRITERIA Randomised, placebo-controlled trials of zinc supplements given at least once a week for at least a month for preventing otitis media. DATA COLLECTION AND ANALYSIS Two review authors assessed the eligibility and methodological quality of the included trials, extracted and analysed data and wrote the review. We summarised results using risk ratios or rate ratios for dichotomous data and mean differences for continuous data. We combined trial results where appropriate. MAIN RESULTS We identified 12 trials for inclusion, 10 of which contributed outcomes data. In trials of healthy children living in low-income communities, two trials did not demonstrate a significant difference between the zinc supplemented and placebo groups in the numbers of participants experiencing an episode of definite otitis media during follow up (3191 participants), while another trial showed a significantly lower incidence rate of otitis media in the zinc group (rate ratio 0.69, 95% confidence interval (CI) 0.61 to 0.79, n = 1621). A small trial of 39 infants undergoing treatment for severe malnutrition suggested a benefit of zinc on the mean number of episodes of otitis media (mean difference -1.12 episodes, 95% CI -2.21 to -0.03). Zinc supplements did not seem to cause any serious adverse events, but a small minority of children were reported to have vomited shortly after ingestion of the supplements. AUTHORS' CONCLUSIONS Evidence on whether zinc supplementation can reduce the incidence of otitis media in healthy children under the age of five years living in low- and middle-income countries is mixed. There is some evidence of benefit in children being treated for marasmus, but this is based on one small trial and should therefore be treated with caution.
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Affiliation(s)
- Katharine Abba
- International Health Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, UK, L3 5QA
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