ABSTRACT

Nearly all mass gathering events worldwide were banned at the beginning of the COVID-19 pandemic, as they were suspected of presenting a considerable risk for the transmission of SARS-CoV-2. We investigated the risk of transmitting SARS-CoV-2 by droplets and aerosols during an experimental indoor mass gathering event under three different hygiene practices, and used the data in a simulation study to estimate the resulting burden of disease under conditions of controlled epidemics. Our results show that the mean number of measured direct contacts per visitor was nine persons and this can be reduced substantially by appropriate hygiene practices. A comparison of two versions of ventilation with different air exchange rates and different airflows found that the system which performed worst allowed a ten-fold increase in the number of individuals exposed to infectious aerosols. The overall burden of infections resulting from indoor mass gatherings depends largely on the quality of the ventilation system and the hygiene practices. Presuming an effective ventilation system, indoor mass gathering events with suitable hygiene practices have a very small, if any, effect on epidemic spread.

Nearly all mass gathering events (MGEs) worldwide have been banned since the outbreak of SARS-CoV-2 as they are supposed to pose a considerable risk for transmission of COVID-19. We investigated transmission risk of SARS-CoV-2 by droplets and aerosols during an experimental indoor MGE (using N95 masks and contact tracing devices) and conducted a simulation study to estimate the resulting burden of disease under conditions of controlled epidemics. The number of exposed contacts was <10 for scenarios with hygiene concept and good ventilation, but substantially higher otherwise. Of subsequent cases, 0%-23% were attributable to MGEs. Overall, the expected additional effect of indoor MGEs on burden of infections is low if hygiene concepts are applied and adequate ventilation exists.

BACKGROUND: Obstetric anal sphincter injury is the primary modifiable risk factor for anal incontinence in women. Currently, endoanal ultrasound is most commonly used to detect residual anal sphincter defects after childbirth. Translabial ultrasound has recently been introduced as a noninvasive alternative. OBJECTIVES: This study aimed to determine medium- to long-term outcomes in women after obstetric anal sphincter injuries diagnosed and repaired at delivery. DESIGN: This is a cross-sectional study. SETTINGS: This study was performed in a tertiary obstetric unit. PATIENTS: Between 2005 and 2015, 707 women were diagnosed with obstetric anal sphincter injuries; 146 followed an invitation for follow-up. INTERVENTIONS: Clinical examination, anal manometry, and translabial ultrasound were performed. MAIN OUTCOME MEASURES: The primary outcomes measured were the St Mark incontinence score and the evidence of sphincter disruption on translabial ultrasound. RESULTS: Of 372 contactable patients, 146 attended at a mean follow-up of 6.6 years (1.7–11.9), of which 75 (51%) reported symptoms of anal incontinence with a median “bother score” of 6 (interquartile range, 3–8). Median St Mark score was 3 (interquartile range, 2–5). Twenty-four (16%) had a score of ≥5. Women who had been diagnosed with a 3c/4th degree tear had more symptoms (58% vs 44%), significantly lower mean maximal resting pressure (p < 0.001), maximal squeeze pressure (p < 0.001), and more residual external (p < 0.001) and internal (p = 0.012) sphincter defects in comparison with those who had a 3a/3b tear. Women with residual external sphincter defects had lower mean maximal squeeze pressure (p = 0.02). Residual internal sphincter defects (p = 0.001) and levator avulsion (p = 0.048) are independent risk factors for anal incontinence on multivariate modeling. LIMITATIONS: This study was limited by the lack of predelivery data of bowel symptoms and BMI and incomplete intrapartum documentation of tear grade. CONCLUSIONS: Symptoms of anal incontinence were highly prevalent (51%), with a high bother score of 6. St Mark scores were associated with residual internal anal sphincter defects and levator avulsion. Women who had a higher tear grade showed a higher incidence of residual sphincter defects and lower manometry pressures. See Video Abstract at http://links.lww.com/DCR/A824.