COVID-19 contact tracing during first delta wave, Lebanon, 2021

Background On the 11th March, the WHO has declared COVID-19 pandemic. Officially, the virus was introduced in Lebanon on the 21st February 2020. Since then, the national curve has drawn several waves. From July to September 2021, Lebanon has experienced the first delta wave. As part of the investigation, contact tracing was enhanced to limit virus transmission. The objective is to describe close tracing approach and profile of close contacts identified during the first delta wave. Methods COVID-19 surveillance is integrated within the national communicable diseases surveillance. The case definitions are adopted from WHO guides. Laboratories report positive cases on daily basis to the Ministry of Public Health, on DHIS2 platform directly or indirectly via excel files importation. Once reported, case investigation is initiated. It includes contact tracing with: 1) identification of close contacts, 2) advice on quarantine and self-monitoring, 3) contact testing. Referral to field testing is made available free of charge for close contacts. Collected data is updated on DHIS2 platform. Later, data is cleaned and analyzed to generate the daily report including description of close contacts. The report is shared with decision makers, professionals, media and public. Results From week 2021W27 to week 2021W40, 85490 cases were reported. Case investigation rate reached 78.8% of the cases were investigated within 24 hours. 66.5% of investigated cases shared lists of contacts, with 3.6 as average number of contacts per case. We identified a total of 161805 close contacts, 95% were from family members, 71% were not vaccinated and 10 % had prior COVID-19 infection. As for contact testing, 65% had RT-PCR test upon investigation, with 32% positive result. Furthermore, 19205 were referred and tested via field testing, with 25% positivity rate. Of all identified contacts, the reported positive tests reached 56,904 representing 35.2% of all contacts. Conclusion During community transmission and mitigation strategy, contact tracing contributes to increase awareness to the contacts and importance to abide to quarantine measures and thus to slow down the virus circulation. Current close contacts are characterized with new profile of prior infection, vaccination history and testing behavior. There is need to adapt the quarantine measures to close contacts based on their profile, and to ensure easy access to free testing. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Institutional Review Board at Rafik Hariri University Hospital, Bir Hassan/Jnah, Lebanon granted the approval to the research entitled "COVID-19 contact tracing during first wave, Lebanon" I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors