Open AccessTransmission of SARS‐CoV‐2 in standardised first few X cases and household transmission investigations: A systematic review and meta‐analysis
Author(s) -
Lewis Hannah C.,
Marcato Adrian J.,
Meagher Niamh,
Valenciano Marta,
VillanuevaCabezas JuanPablo,
Spirkoska Violeta,
Fielding James E.,
Karahalios Amalia,
Subissi Lorenzo,
Nardone Anthony,
Cheng Brianna,
Rajatonirina Soatiana,
Okeibunor Joseph,
Aly Eman A.,
Barakat Amal,
Jorgensen Pernille,
Azim Tasnim,
Wijesinghe Pushpa R.,
Le LinhVi,
Rodriguez Angel,
Vicari Andrea,
Van Kerkhove Maria D.,
McVer Jodie,
Pebody Richard,
Price David J.,
Bergeri Isabel
Publication year - 2022
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.13002
Subject(s) - meta analysis , confidence interval , medicine , medline , systematic review , transmission (telecommunications) , web of science , forest plot , pandemic , epidemiology , scopus , covid-19 , pathology , biology , infectious disease (medical specialty) , disease , computer science , telecommunications , biochemistry
We aimed to estimate the household secondary infection attack rate (hSAR) of SARS‐CoV‐2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta‐analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for “Unity‐aligned” First Few X cases (FFX) and HHTIs published 1 December 2019 to 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta‐analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review; 62 were included in the primary meta‐analysis. hSAR point estimates ranged from 2% to 90% (95% prediction interval: 3%–71%; I 2 = 99.7%); I 2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence‐based pandemic preparedness and response efforts for SARS‐CoV‐2, influenza and future novel respiratory viruses.