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During August 7-16, 2020, a motorcycle rally was held in western South Dakota that attracted approximately 460,000 persons from across the United States to numerous indoor and outdoor events over a 10-day period. During August-September 2020, the Minnesota Department of Health (MDH) investigated a coronavirus disease 2019 (COVID-19) outbreak associated with the rally in Minnesota residents. Fifty-one primary event-associated cases were identified, and 35 secondary or tertiary cases occurred among household, social, and workplace contacts, for a total of 86 cases; four patients were hospitalized, and one died. Approximately one third (34%) of 87 counties in Minnesota had at least one primary, secondary, or tertiary case associated with this rally. Genomic sequencing supported the associations with the motorcycle rally. These findings support current recommendations for mask use, physical distancing, reducing the number of attendees at gatherings, isolation for patients with COVID-19, and quarantine for close contacts to slow the spread of SARS-CoV-2 (1). Furthermore, although these findings did not capture the impact of the motorcycle rally on residents of other states, they demonstrate the rationale for consistent mitigation measures across states.

Background The distribution of Clostridioides difficile strains and transmission dynamics in the United States are not well defined. Whole-genome sequencing across 2 Centers for Disease Control and Prevention Emerging Infections Program C. difficile infection (CDI) surveillance regions (Minnesota and New York) was performed to identify predominant multilocus sequence types (MLSTs) in community-associated (CA) and healthcare-associated (HCA) disease and assess transmission. Methods Whole-genome sequencing was performed on C. difficile isolates from patients with CDI over 3 months between 2016 and 2017. Patients were residents of the catchment area without a positive C. difficile test in the preceding 8 weeks. CDI cases were epidemiologically classified as HCA or CA. Results Of 422 isolates, 212 (50.2%) were HCA and 203 (48.1%) were CA. Predominant MLSTs were sequence type (ST) 42 (9.3%), ST8 (7.8%), and ST2 (8.1%). MLSTs associated with HCA-CDI included ST1 (76%), ST53 (83.3%), and ST43 (80.0%), while those associated with CA-CDI included ST3 (76.9%) and ST41 (77.8%). ST1 was more frequent in New York than in Minnesota (10.8% vs 3.1%). Thirty-three pairs were closely related genomically, 14 of which had potential patient-to-patient transmission supported by record review. Conclusions The genomic epidemiology of C. difficile across 2 regions of the United States indicates the presence of a diverse strain profile and limited direct transmission.

Congregate settings and high-density workplaces have endured a disproportionate impact from COVID-19. In order to provide further understanding of the transmission patterns of SARS-CoV-2 in these settings, whole genome sequencing (WGS) was performed on samples obtained from 8 selected outbreaks in Minnesota from March – June, 2020. WGS and phylogenetic analysis was conducted on 319 samples, constituting 14.4% of the 2,222 total SARS-CoV-2-positive individuals associated with these outbreaks. Among the sequenced specimens, three LTCFs and both correctional facilities had spread associated with a single genetic sequence. A fourth LTCF had outbreak cases associated with two distinct sequences. In contrast, cases associated with outbreaks in the two meat processing plants represented multiple SARS-CoV-2 sequences. These results suggest that a single introduction of SARS-CoV-2 into a facility can result in a widespread outbreak, and early identification and cohorting of cases, along with continued vigilance with infection prevention and control measures is imperative.

Background Clostridium difficile infection (CDI) incidence has increased dramatically in the past decade, making CDI one of the most common causes of infectious diarrhea and an urgent public health threat. Understanding the biological features and spread of C. difficile strains can help target control efforts. PCR-ribotyping, the current method of choice for C. difficile typing, remains subjective and challenging for interlaboratory comparisons. Multilocus sequence typing (MLST), based on the alleles of seven housekeeping genes, represents a more robust tool that would enhance interlaboratory reproducibility. However, a comprehensive translation system to ribotyping is a prerequisite. Here, we describe the concordance between MLST and PCR-ribotyping. Methods The Centers for Disease Control and Prevention’s (CDC) Emerging Infections Program (EIP) conducts CDI surveillance in 10 US sites. C. difficile isolates cultured from a subset of cases underwent capillary-based PCR-ribotyping at CDC. A representative sample, selected from the top 30 ribotypes (RTs), underwent whole genome sequencing (WGS) at Minnesota Department of Health. An additional subset of isolates, representing the top 10 RTs, underwent WGS at CDC. At both laboratories, the Illumina MiSeq platform was used to obtain 250 bp paired-end sequencing reads. MLST analyses were done using the pubMLST C. difficile scheme. Results A total of 479 C. difficile isolates, including at least 10 isolates for each RT, were analyzed by WGS. Among the 30 RTs represented, 35 different MLST sequence types (STs) were identified. Twenty-two of the RTs (including 027) were each associated with a single unique ST, while 8 RTs (020, 014, 015, 076, 046, 153–251, A27, and 075) presented more genetic diversity with single-locus or double-locus variants, resulting in multiple STs within one ribotype. There were two instances of two different RTs sharing the same ST. Conclusion Multilocus sequence typing and PCR-Ribotyping showed comparable discriminatory abilities. However, the ST is not always predictive of the RT and vice versa. This represents the first step toward a transition to using WGS for standard C. difficile typing. Disclosures All authors: No reported disclosures.