RESUMEN
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 between 1 December 2019 and 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 and 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2%-90% (95% prediction interval: 3%-71%; I2=99.7%); I2 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.
RESUMEN
COVID-19 affected different countries in different ways. Palestine had recorded over 140,000 cases by the end of 2020. The WHO/PNIPH, WHO/EMRO, and the Palestinian MoH carried out a serological survey in Palestine in order to estimate the actual number of COVID-19 infections up to the end of December 2020. A sample stratified by region, district, residence area (urban, rural, and refugee camp), and accounting for gender, was taken from Gaza and the West Bank. Data from participants were also collected, including demographic, socio-economic, and health conditions. The results show that 39% of the Palestinian population (38% of the West Bank and 40% of Gaza) had been infected with COVID-19 by the end of December, almost 10 times the number detected by targeted Rt-PCR testing. Several factors were calculated to be significant such as diabetes, smoking, gender, age, and residence. Summary of findingsThe following table is a summary of all findings presented in this report. The P values in green are below 0.05, which makes the result statistically significant; red is not statistically significant. In binary comparisons (when comparing two numbers), the odds were calculated, meaning how much more likely the presence of seropositivity is if the condition is satisfied. For example, those who were previously diagnosed as COVID-19 positive using Rt PCR were 2.5 times as likely to be seropositive than those who were not diagnosed. O_TBL View this table: org.highwire.dtl.DTLVardef@86dda2org.highwire.dtl.DTLVardef@40e102org.highwire.dtl.DTLVardef@17454b1org.highwire.dtl.DTLVardef@6448cdorg.highwire.dtl.DTLVardef@1e7cb8e_HPS_FORMAT_FIGEXP M_TBL C_TBL
