ABSTRACT
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect many wild and domestic animal species. Farmed American mink (Neovison vison) are particularly susceptible to infection. Outbreaks of SARS-CoV-2 were detected in farmed mink on three mink farms in British Columbia (BC), Canada between December 2020 and May 2021. In BC, mink farm density and proximity to wildlife habitats increase transmission risks from infected farmed mink. The objective of this study is to investigate the risk of SARS-CoV-2 spreading to and from wildlife in the area surrounding infected mink farms in BC, Canada, as well as to compare the effectiveness of physical and camera trapping surveillance methodologies. Methods: A combination of physical and camera trapping was used on and around three BC mink farms with active SARS-CoV-2 infections between January 22, 2021, and July 10, 2021. Samples from trapped animals, including escaped farmed mink, were tested for SARS-CoV-2. Camera images from one mink farm were reviewed to determine species and proximity to the mink barn. Results: Seventy-one animals of nine species were captured and sampled. Three captured mink tested positive for SARS-CoV-2 by polymerase chain reaction and serology; the remaining samples were negative for SARS-CoV-2. Genotyping of the three positive mink indicated these were domestic (vs. wild) mink. A total of 440 animals of 16 species were photographed at the one farm where cameras were deployed. Conclusion: Detection of SARS-CoV-2 in escaped farmed mink is concerning and demonstrates the potential for transmission from farmed mink to wildlife, particularly given the observation of wildlife known to be susceptible to SARS-CoV-2 near infected mink farms. Combined use of physical and camera trapping contributed to the breadth of the results and is strongly recommended for future surveillance.
ABSTRACT
BACKGROUND: Cervical cancer, a preventable disease associated with the human papillomavirus, is responsible for significant morbidity and mortality globally. Primary human papillomavirus testing is more sensitive in detecting precancerous cervical lesions than cytologic screening and can be conducted using either DNA- or RNA-based assays. Screening programs must select the most appropriate assay from several available assays for their population. It is not yet known whether these assays perform equivalently in the long term, particularly among women with a negative human papillomavirus test result. This study aims to compare long-term safety after a negative human papillomavirus test result across both DNA- and RNA-based testing assays. OBJECTIVE: This study aimed to compare long-term high-grade cervical intraepithelial neoplasia (grade 2 or higher and grade 3 or higher) outcomes of 2 DNA-based assays (Digene Hybrid Capture 2 High-Risk HPV DNA Test and cobas 4800 HPV Test) and 1 messenger RNA-based assay (Aptima HPV Assay) using data from the Human Papillomavirus For Cervical Cancer Trial-DECADEl (FOCAL-DECADE) cohort, by first comparing the positive and negative rates between the assays and then investigating the cumulative incidence of cervical intraepithelial neoplasia grade 2 and higher and grade 3 or higher detection among participants in the FOCAL DECADE cohort over follow-up according to human papillomavirus testing assays. STUDY DESIGN: The FOCAL Trial was a randomized controlled trial that evaluated human papillomavirus testing for primary cervical cancer screening. The FOCAL-DECADE cohort subsequently followed FOCAL Trial participants passively through the British Columbia Cervix Screening Program Database for approximately 10 years after the FOCAL Trial study exit to examine the rates of cervical intraepithelial neoplasia grade 2 or higher and grade 3 or higher. For this study, eligible participants had baseline human papillomavirus-negative results from at least 1 assay and had 1 or more cytologic screens after baseline (9509 participants for DNA-based and 3473 participants for DNA- vs RNA-based assay comparisons). We constructed cumulative incidence curves and compared the hazard ratios for cervical intraepithelial neoplasia grade 2 or higher and grade 3 or higher detection according to the assays. RESULTS: Over 10 years of follow-up, the cumulative incidence of cervical intraepithelial neoplasia grade 2 or higher and grade 3 or higher did not significantly differ between the DNA-based assays (hazard ratio, 0.95; 95% confidence interval, 0.84-1.06; P=.35 and hazard ratio, 0.82; 95% confidence interval, 0.66-1.01; P=.06 for cervical intraepithelial neoplasia grade 2 or higher and cervical intraepithelial neoplasia grade 3 or higher, respectively) or between the DNA- and RNA-based assays (hazard ratio, 0.97; 95% confidence interval, 0.87-1.06; P=.48 and hazard ratio, 0.94; 95% confidence interval, 0.79-1.13; P=.52 for cervical intraepithelial neoplasia grade 2 or higher and cervical intraepithelial neoplasia grade 3 or higher, respectively). CONCLUSION: Among participants who tested negative for human papillomavirus at baseline, the long-term risk of cervical intraepithelial neoplasia grade 2 or higher and grade 3 or higher did not significantly differ regardless of whether DNA- or RNA-based human papillomavirus testing assays were used. Screening program decision makers can be confident that for women who test negative for human papillomavirus, DNA- and RNA-based assays exhibit similar cervical intraepithelial neoplasia grade 2 or higher outcomes over several years.