Background The prevention of chronic diseases has always been a major focus in the medical field as a measure to improve public health. As a potential prevention to one of the most common chronic diseases, vitamin D was previously reported to show some signs of positive effect on the prevention of upper respiratory tract infections. Although trials were performed to demonstrate the association between the effectiveness of vitamin D and upper respiratory tract infections in the past few years, the number of randomized controlled trials was limited. Only one systematic review with meta-analysis was carried out to study the effect of vitamin D supplementation on prevention of respiratory tract infections (Charan et al., 2012). Aim A systematic review of the existing evidence was carried out with the aim to examine the effectiveness of vitamin D supplementation as an intervention in prevention of upper respiratory tract infections. Method Studies were selectively chosen based on the inclusion and exclusion criteria. Retrieval of studies was performed and identified from MEDLINE (Ovid) and PUBMED. MeSH terms of “Vitamin D” and “Upper respiratory tract infections” were applied in the search. Only randomized controlled trials were selected. Non-English publications, reviews, discussions, conference papers, and publications with outcomes being not incidence of URTI, were excluded. The quality of each study was evaluated using the Jadad scale (Jadad et al., 1996). Data from the trials was extracted into the meta-analysis, and odds ratios and confidence intervals were used as measures of the association between vitamin D supplementation and incidence of upper respiratory tract infections across studies. Result Five randomized controlled trials were included in this review. In this meta-analysis, the number of events of upper respiratory tract infections in vitamin D group was lower than that in the placebo group (OR=0.53), suggesting that a 47% lower odds of falling in vitamin D groups than in controls. The 95% confidence interval ranged from 0.30to 0.93and did not include 1, suggesting that the effect of vitamin D on prevention of upper respiratory tract infections was significant. However, when the trials were divided into children and adult groups, the results were significantly different. The result of the trials with two children gave an OR of 0.33(95%CI: 0.13, 0.83), meaning a positive effect of vitamin D could be observed in the vitamin D group, compared to the placebo group. Meanwhile, three trials on adults had an OR of 0.78 (95%CI: 0.56, 1.09), which was insufficient to suggest the two groups were different. Conclusion While the positive effect of vitamin D supplementation for the prevention of upper respiratory tract infections is evident on children in this review, it is much less significant on adults due to inconsistencies in the results. Therefore, more research and trials with improved methodologies would be required in the future to increase our understanding and provide more certainty on this matter. / published_or_final_version / Public Health / Master / Master of Public Health

Thesis (MCur)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Annually more than 3.5 million children worldwide, less than five years of age die of diarrhoea and acute lower respiratory-tract infections. Over the last two decades, the care of pre-school children outside of their homes has become more common in most parts of the world and has contributed to an increased risk of respiratory-tract and gastrointestinal infections in children. Children attending day-care centres are at an increased risk for diarrhoea and respiratory-tract infections and hands are the primary vehicle for transmission of infectious diseases. Thus, hand hygiene is essential for preventing and controlling of infection in the health care and community settings. Waterless hand sanitizer as an alternative to hand washing was investigated. Rinse-free hand sanitizer programmes in the community may be effective, safe and feasible. The aim of the study was to systematically appraise evidence on the effect of alcohol-based hand rub in the prevention of diarrhoea and acute respiratory-tract infection among children aged five years and below in community settings. The primary outcome of the study was to assess the incidence of respiratory-tract infection and diarrhea. Diarrhoea is defined by the World Health Organization as the excretion of three or more loose or liquid stools per day (or more frequent excretion than is normal for the individual). The secondary outcome was to assess mortality, admission to hospital and duration of hospital stay. A comprehensive search for relevant studies was conducted on the following databases from 1990 to 2014: EMBASE, MEDLINE, CINAHL, Google Scholar and Cochrane Central Register of Controlled Trials (CENTRAL). We searched the reference lists of all relevant articles and textbooks for more studies. Unpublished data previously presented at international and scientific meetings have been included in the review. Proceedings of international conferences on diarrhoea and respiratory-tract infection among children were searched for relevant articles. Subject experts were contacted. Two reviewers, Joelynn Steyn (JS) and Oswell Khondowe (OK) selected studies following a two-step study selection process. This review considered all published randomized controlled trials and quasi-experimental designs published from January 1990 to July 2014. The first step was the selection of studies based on titles and abstracts. Both reviewers selected eligible studies which met the set criteria. During the second step, both reviewers retrieved the full-text articles of the studies and assessed the methodological quality of the studies. Four studies were included in this review. The included studies met most of the quality assessment criteria as stipulated in the Cochrane risk assessment tool. Two studies were clusterrandomized controlled trials, one was a block randomized controlled trial and one was a randomized controlled trial. Disagreements were resolved by discussion and where a lack of consensus existed, consultation with a third reviewer occurred. The use of alcohol hand rub as compared to control interventions significantly reduced the incidence of diarrhoea in children (RR 0.79, 95% CI 0.63 to 0.99). Statistical heterogeneity was observed among the included studies (I²=69, p=0.04). However this review found no significant difference in respiratory-tract infections between intervention groups versus control as observed from the confidence interval (RR 0.98, 95% CI 0.90 to 1.07, p=0.63). The results should be interpreted with caution due to the limited number of studies conducted in communities with alcoholbased hand rub used by caregivers. Due to limited studies in this review, it makes it difficult to make strong conclusions on findings and to provide sufficient evidence to guide future research. We therefore recommend that more studies with high quality methodologies, using randomized controlled trial designs be conducted especially in poor resourced communities. / AFRIKAANSE OPSOMMING: Meer as 3.5 miljoen kinders jonger as vyf jaar oud sterf jaarliks wêreldwyd as gevolg van diarree en akute laer respiratoriese lugweginfeksies. Oor die laaste dekades het die versorging van voorskoolse kinders buite hul tuiste meer algemeen geword in die meeste dele van die wêreld wat bygedra het tot ’n risiko in die toename van respiratoriese en spysverteringskanaalinfeksies by kinders. Kinders by dagsorgsentrums het ’n groter risiko vir diarree en respiratoriese lugweë infeksies want die oordra van siekte-infeksies word veral deur die hande wat as die primêre bron daarvan beskou word, gesien. Dus is hand-higiëne noodsaaklik om infeksies in gesondheidsorg en gemeenskapsentrums te voorkom en te beheer. ’n Waterlose hande-ontsmettingsmiddel as ’n alternatief om hande te was, is ondersoek. Spoelvrye hande-ontsmettingsmiddel programme in die gemeenskap mag effektief, veilig en uitvoerbaar wees. Die doel van die studie was om sistematies die geslaagdheid van bewyse op die effek van alkoholgebaseerde hande-smeermiddel in die voorkoming van diarree en akute lugweginfeksies by kinders 5 jaar en jonger in gemeenskapsentrums te ondersoek. Die primêre uitkoms van die studie was om die voorkoms van respiratoriese lugweginfeksie en diarree te asseseer. Diarree soos gedefinieer deur die WGO is die uitskeiding van drie of meer los- of waterige stoelgange per dag (of meer gereelde uitskeiding wat normaal vir die individu is). Die sekondêre uitkoms was om mortaliteit, toelating tot die hospitaal en duur van hospitaalverblyf te assesseer. ’n Omvattende soektog vir relevante studies was op die volgende databasisse van 2004-2014 uitgevoer: EMBASE, MEDLINE, CINAHL, Google Scholar en Cochrane Sentrale Register van Beheerde Toetse. Ons het die verwysingslyste van alle relevante artikels en handboeke vir meer navorsingstudies nagegaan. Ongepubliseerde data wat voorheen aangebied is by internasionale en wetenskaplike vergaderings, is ingesluit in die oorsig. Bevindings by internasionale konferensies oor diarree en lugweginfeksies by kinders was nagegaan in die soektog na relevante artikels. Onderwerpdeskundiges was gekontak. Die twee navorsers, Joelynn Steyn (JS) en Oswell Khondowe (OK) het studies geselekteer deur ’n twee-stap studieselekteringsproses te volg. Die oorsig het alle gepubliseerde, ewekansige gekontroleerde proewe en kwasi-eksperimenteerde studies oorweeg tussen Januarie 1990 en Julie 2014. Die eerste stap was die selektering van studies gebaseer op hul titels en opsommings. Beide navorsers het geskikte studies slegs geselekteer as die studie aan die bepaalde kriteria voldoen het. Tydens die tweede stap het beide navorsers die volledige artikels geneem van die studies geselekteer en die gehalte van die metodologie geassesseer. Vierstudies is in die oorsig ingesluit. Die ingeslote studies het aan die meeste vereistes soos deur die Cochrane risiko assesseringsinstrument gestipuleer voldoen. Twee studies was groep-ewekansige gekontroleerde proewe, een was ’n blok ewekansige gekontroleerde proef en een was ’n ewekansige gekontroleerde proef. Verskille is opgelos deur bespreking en waar daar onderbreking in konsensus was, het ’n konsultasie met ’n derde beoordelaar plaasgevind. Die gebruik van ’n alkohol handreiniger, soos vergelyk met kontrole-intervensies, het die voorkoms van diarree in kinders beduidend verminder (RR 0.79, 95% CI 0.63 to 0.99). Statistiese heterogeniteit is egter tussen die ingeslote studies waargeneem (I²=69, p=0.04). Hierdie studie het geen beduidende verskille in lugweg infeksies tussen die intervensiegroepe teenoor die kontrolegroep gevind nie soos waargeneem uit die vertroue interval (RR0.98, 95% CI 0.90 to 1.07, p=0.63). Die resultate moet met omsigtigheid geïnterpreteer word as gevolg van die beperkte aantal studies wat in gemeenskappe uitgevoer was met alkohol-gebasseerde handreiniger wat deur versorgers gebruik word. As gevolg van die beperkende aantal studies in hierdie studie, is dit moeilik om sterk gevolgtrekkings te maak op bevindinge en om voldoende bewyse te gee om toekomstige navorsing te rig. Ons beveel dus aan dat meer studies met hoë kwaliteit metodologie en wat ewekansige gekontroleerde proef-ontwerpe gebruik, uitgevoer word, veral in swak-toegeruste gemeenskappe. (RR0.98, 95% CI 0.90 to 1.07, p=0.63). Die resultate moet met omsigtigheid geïnterpreteer word as gevolg van die beperkte aantal studies wat gedoen is in gemeenskappe met alkohol-