scholarly journals Social contact patterns and implications for infectious disease transmission: a systematic review and meta-analysis of contact surveys

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Andria Mousa ◽  
Peter Winskill ◽  
Oliver John Watson ◽  
Oliver Ratmann ◽  
Mélodie Monod ◽  
...  

Background: Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focussed on high-income settings. Methods: Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys we explored how contact characteristics (number, location, duration and whether physical) vary across income settings.Results: Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age-groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, with low-income settings characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income-strata on the frequency, duration and type of contacts individuals made. Conclusions: These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens, as well as the effectiveness of different non-pharmaceutical interventions. Funding: This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1).

2021 ◽  
Author(s):  
Andria Mousa ◽  
Peter Winskill ◽  
Oliver John Watson ◽  
Oliver Ratmann ◽  
Mélodie Monod ◽  
...  

Background: Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focussed on high-income settings. <br />Methods: Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys we explored how contact characteristics (number, location, duration and whether physical) vary across income settings.<br />Results: Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age-groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, but low-income settings were characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income-strata on the frequency, duration and type of contacts individuals made.<br />Conclusions: These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens, as well as the effectiveness of different non-pharmaceutical interventions.<br />Funding: This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1).


2014 ◽  
Vol 18 (3) ◽  
pp. 500-520 ◽  
Author(s):  
Helena Carreira ◽  
Ana Bastos ◽  
Bárbara Peleteiro ◽  
Nuno Lunet

AbstractObjectiveTo quantify the association between breast-feeding and Helicobacter pylori infection, among children and adolescents.DesignWe searched MEDLINETM and ScopusTM up to January 2013. Summary relative risk estimates (RR) and 95 % confidence intervals were computed through the DerSimonian and Laird method. Heterogeneity was quantified using the I2 statistic.SettingTwenty-seven countries/regions; four low-income, thirteen middle-income and ten high-income countries/regions.SubjectsStudies involving samples of children and adolescents, aged 0 to 19 years.ResultsWe identified thirty-eight eligible studies, which is nearly twice the number included in a previous meta-analysis on this topic. Fifteen studies compared ever v. never breast-fed subjects; the summary RR was 0·87 (95 % CI 0·57, 1·32; I2=34·4 %) in middle-income and 0·85 (95 % CI 0·54, 1·34; I2=79·1 %) in high-income settings. The effect of breast-feeding for ≥4–6 months was assessed in ten studies from middle-income (summary RR=0·66; 95 % CI 0·44, 0·98; I2=65·7 %) and two from high-income countries (summary RR=1·56; 95 % CI 0·57, 4·26; I2=68·3 %). Two studies assessed the effect of exclusive breast-feeding until 6 months (OR=0·91; 95 % CI 0·61, 1·34 and OR=1·71; 95 % CI 0·66, 4·47, respectively).ConclusionsOur results suggest a protective effect of breast-feeding in economically less developed settings. However, further research is needed, with a finer assessment of the exposure to breast-feeding and careful control for confounding, before definite conclusions can be reached.


2021 ◽  
pp. archdischild-2020-321385
Author(s):  
Omar Irfan ◽  
Fiona Muttalib ◽  
Kun Tang ◽  
Li Jiang ◽  
Zohra S Lassi ◽  
...  

ObjectiveCompare paediatric COVID-19 disease characteristics, management and outcomes according to World Bank country income level and disease severity.DesignSystematic review and meta-analysis.SettingBetween 1 December 2019 and 8 January 2021, 3350 articles were identified. Two reviewers conducted study screening, data abstraction and quality assessment independently and in duplicate. Observational studies describing laboratory-confirmed paediatric (0–19 years old) COVID-19 were considered for inclusion.Main outcomes and measuresThe pooled proportions of clinical findings, treatment and outcomes were compared according to World Bank country income level and reported disease severity.Results129 studies were included from 31 countries comprising 10 251 children of which 57.4% were hospitalised. Mean age was 7.0 years (SD 3.6), and 27.1% had a comorbidity. Fever (63.3%) and cough (33.7%) were common. Of 3670 cases, 44.1% had radiographic abnormalities. The majority of cases recovered (88.9%); however, 96 hospitalised children died. Compared with high-income countries, in low-income and middle-income countries, a lower proportion of cases were admitted to intensive care units (ICUs) (9.9% vs 26.0%) yet pooled proportion of deaths among hospitalised children was higher (relative risk 2.14, 95% CI 1.43 to 3.20). Children with severe disease received antimicrobials, inotropes and anti-inflammatory agents more frequently than those with non-severe disease. Subgroup analyses showed that a higher proportion of children with multisystem inflammatory syndrome (MIS-C) were admitted to ICU (47.1% vs 22.9%) and a higher proportion of hospitalised children with MIS-C died (4.8% vs 3.6%) compared with the overall sample.ConclusionPaediatric COVID-19 has a favourable prognosis. Further severe disease characterisation in children is needed globally.


2020 ◽  
Vol 4 (1) ◽  
pp. e000662 ◽  
Author(s):  
Nick Brown ◽  
Antti Juhani Kukka ◽  
Andreas Mårtensson

BackgroundDespite advances in vaccination and case management, pneumonia remains the single largest contributor to early child mortality worldwide. Zinc has immune-enhancing properties, but its role in adjunctive treatment of pneumonia in low-income and middle-income countries (LMICs) is controversial and research still active.MethodsSystematic review and meta-analysis of randomised controlled trials of zinc and placebo in pneumonia in children aged 2 to 60 months in LMICs. Databases included MEDLINE, the Cochrane Library, EMBASE, LILACS, SciELO, the WHO portal, Scopus, Google Scholar and ClinicalTrials.gov. Inclusion criteria included accepted signs of pneumonia and clear measure of outcome. Risk of bias was independently assessed by two authors. ORs with 95% CI were used for calculating the pooled estimate of dichotomous outcomes including treatment failure and mortality. Time to recovery was expressed as HRs. Sensitivity analyses considering risk of bias and subgroup analyses for pneumonia severity were performed.ResultsWe identified 11 trials published between 2004 and 2019 fulfilling the a priori defined criteria, 7 from South Asia and 3 from Africa and 1 from South America. Proportional treatment failure was comparable in both zinc and placebo groups when analysed for all patients (OR 0.95 (95% CI 0.80 to 1.14)) and only for those with severe pneumonia (OR 0.93 (95% CI 0.75 to 1.14)). No difference was seen in mortality between zinc and placebo groups (OR 0.64 (95% CI 0.31 to 1.31)). Time to recovery from severe pneumonia did not differ between the treatment and control groups for patients with severe pneumonia (HR 1.01 (95% CI 0.89 to 1.14)). Removal of four studies with high risk of bias made no difference to the conclusions.ConclusionThere is no evidence that adjunctive zinc treatment improves recovery from pneumonia in children in LMICs.Trial registration numberCRD42019141602.


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