Epidemiological investigation of COVID-19 cluster at a wedding ceremony in March 2021 at Rawat, Pakistan – A Retrospective Cohort Study
On 9th March 2021, 18 people with fever, flu and shortness of breath reported at a local hospital. All attended a wedding ceremony and got positive for COVID-19. We carried out this investigation to determine the epidemiological characteristics and associated risk factors responsible for transmission.
A retrospective cohort study was conducted among 382 wedding attendees. A case was defined as any person positive on Reverse-transcription polymerase-chain-reaction within 14 days of event. Contact were those interacted with positive case <6 feet for ≥15 minutes. All attendees were identified and traced by family head and tested for SARS-CoV-2. Data was collected through pre-tested structured questionnaire. Descriptive analysis was done attack rates were computed. Risk factors were evaluated by applying logistic regression at CI: 95% and p-value <0.05.
Of the 382 attendees, 40 % (n=151) found positive. Median age of the cases was 34 years, male to female ratio was 1:1. The median incubation period was 4 days. Among all positive cases 62% (n=94) were females, 62 % (n = 94) were symptomatic, 36 % (n = 34) of these developed severe symptoms, 11% (n=10) were hospitalized and one death reported. Most affected age group was 11- 20 years with an attack rate of 59 %. Secondary attack rate was 34 %. Indoors sitting (RR = 142, 95 % CI = 109 – 184), unvaccinated (RR = 44, 95 % CI = 30 – 63) and not wearing a mask (RR = 40, 95 % CI = 30 – 53) found statistically significant.
Indoor sitting arrangement was made only for females thus found strongly associated with the transmission of infection among females, whereas risk of getting infection was also high among those who did not use face mask and unvaccinated. It is recommended to implement and monitor both social and personal protective measures.