Transmission of SARS-CoV-2 in standardised First Few X cases and household transmission investigations: a systematic review and meta-analysis

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.

Integration of leprosy services into the General Health Service in Sri Lanka: overcoming challenges to implementation in a remote district

Sri Lanka took a policy decision to integrate leprosy services into the generalhealth services (GHS) in 1999. This paper aims to summarize the emergence ofnew, specific challenges and how they were overcome during the integration ofleprosy services to the GHS in a remote, leprosy endemic district in Sri Lanka.In this article, the regional epidemiologist as the team leader describes theprinciples used for transition to an effective integrated model of leprosy servicesfrom a centralized leprosy control model in the district. In addition, rationale forintegration is viewed from the epidemiological and operational perspectives.National and district leprosy epidemiological data from secondary sources arealso reviewed for corroborating the effectiveness of integration. Challengessurfaced were mainly related to the transfer of ownership of the programme,selection of appropriate service providing institutions easily accessible toclients, sustainability of leprosy services at the GHS, ensuring participation of allstakeholders in capacity building programmes and co‑ordination of patient care inthe absence of a dermatologist in the district. An empowered district team leaderwith specified roles and responsibilities, his sound technical and managerialknow how and ability to translate ‘team work’ concept to practice were foundto be essential for successful implementation of integration. Decision‑makingpowers at the district level and flexibility to introduce new, area‑specific changesto the centrally prepared core activities of integration were also vital to overcomelocally surfaced challenges.

Annual risk of tuberculosis infection in Sri Lanka: a low prevalent country with a high BCG vaccination coverage in the South-East Asia Region

Introduction: Despite its simplicity, efficiency and reliability, Sri Lanka has notused the Annual Risk of Tuberculosis Infection (ARTI) to assess the prevalenceand efficiency of tuberculosis (TB) control. Hence, a national tuberculin surveywas conducted to estimate the ARTI.Materials and Methods: A school‑based, cross‑sectional tuberculin survey of4352 children aged 10 years irrespective of their BCG vaccination or scar statuswas conducted. The sample was selected from urban, rural and estate strata usingtwo‑stage cluster sampling technique. In the first stage, sectors representing threestrata were selected and, in the second stage, participants were selected from120 clusters. Using the mode of the tuberculin reaction sizes (15 mm) and themirror‑image technique, the prevalence and the ARTI were estimated.Results: The prevalence of TB estimated for urban, rural and estate sectors were13.9%, 2.2% and 2.3%, respectively. The national estimate of the prevalenceof TB was 4.2% (95% CI = 1.7-7.2%). ARTI for the urban, rural and estatesectors were 1.4%, 0.2% and 0.2%, respectively, and the national estimate was0.4% (95% CI = 0.2-0.7%). The estimated annual burden of newly infected orre‑infected TB cases with the potential of developing into the active disease(400/100 000 population) was nearly 10‑fold higher than the national new casedetection rate (48/100 000 population).Conclusion: The national estimate of ARTI was lower than the estimates for manydeveloping countries. The high‑estimated risk for the urban sector reflected theneed for intensified, sector‑specific focus on TB control activities. This underscoresthe need to strengthen case detection. Repeat surveys are essential to determinethe annual decline rate of infection.