PREVALENCE OF COVID 19 AMONG RETURNING PILGRIMS AT ISLAMABAD INTERNATIONAL AIRPORT, PAKISTAN; A RETROSPECTIVE COHORT STUDY

INTRO: Mass gathering events (MGEs) are associated with the transmission of COVID-19. The world's largest mass gathering hajj pilgrimage 2022 was held after two years of major disruption caused by the COVID pandemic, with one million pilgrims of different ages, health statuses, hygiene sophistication and close contact. This study aimed to estimate the Prevalence of COVID-19 among returning Pakistani pilgrims at Islamabad International Airport, its association with these MGEs and to quantify the potential risk factors associated. METHODS: A retrospective cohort study was carried out at Islamabad International Airport from 14th July to 13th August 2022. A representative sample of 1100 people with potential exposure at Hajj 2022 was surveyed by a questionnaire to obtain information about attendance at hajj and COVID-19 disease. In addition, Rapid antigen testing (RAT) against SARS-Cov-2 was implemented. Statistical analysis was done using Epi info version 7. FINDINGS: A total of 1100 subjects participated in the questionnaire survey and underwent rapid antigen testing. The mean age was 49.7±10.4. Almost 17.9% of the respondents experienced Covid-like symptoms with sore throat and fever as the most frequent symptoms. Three cases were detected by RAT with an attack rate (AR) of 0.3%; 79.7% were female. Considering MGE exposure, AR was 0.2 %. All participants were fully vaccinated with 86.5% boosted with one dose. A dose- response relationship was found between MGE attendance and the disease, (adjusted relative risk [ARR] = 3.4- 5% confidence interval [CI] 2.25–3.5). Associated risk factors with the incidence were co-morbidity (RR=5.2) and non- use of face masks (RR=9). CONCLUSION: The study highlights the significance of MGEs in COVID-19 transmission. Vaccination and booster shots significantly reduced the risk of Covid-19 transmission among the returning pilgrims. With surveillance, screening and Rapid antigen testing at Points of entry, risk of future pandemics is significantly reduced.