Limited information is available on the natural history of Clostridioides difficile colonization and infection in patients with new acquisition of C. difficile in healthcare settings. In 3 hospitals and affiliated long-term care facilities, we collected serial perirectal cultures from patients with no diarrhea on enrollment to identify new acquisition of toxigenic C. difficile carriage and determined the duration and burden of carriage. Asymptomatic carriage was defined as transient if only 1 culture was positive with negative cultures before and after or persistent if 2 or more cultures were positive. Clearance of carriage was defined as 2 consecutive negative perirectal cultures. Of 1,432 patients with negative initial cultures and at least 1 follow-up culture, 39 (2.7%) developed CDI without prior detection of carriage and 142 (9.9%) acquired asymptomatic carriage with 19 (13.4%) subsequently diagnosed with CDI. Of 82 patients analyzed for persistence of carriage, 50 (61.0%) had transient carriage and 32 (39.0%) had persistent carriage, with an estimated median of 77 days to clearance of colonization (range, 14 to 133 days). Most persistent carriers had a relatively high burden of carriage and maintained the same ribotype over time, whereas most transient carriers had a low burden of carriage detected only using broth enrichment cultures. In 3 healthcare facilities, 9.9% of patients acquired asymptomatic carriage of toxigenic C. difficile, and 13.4% were subsequently diagnosed with CDI. Most carriers had transient rather than persistent carriage and most patients developing CDI did not have prior detection of carriage.

Background: The incubation period for Clostridioides difficile infection (CDI) is generally considered to be less than 1 week, but some recent studies suggest that prolonged carriage prior to disease onset may be common. Objective: To estimate the incubation period for patients developing CDI after initial negative cultures. Methods: In 3 tertiary care medical centers, we conducted a cohort study to identify hospitalized patients and long-term care facility residents with negative initial cultures for C. difficile followed by a diagnosis of CDI with or without prior detection of carriage. Cases were classified as healthcare facility-onset, community-onset, healthcare facility-associated, or community-associated and were further classified as probable, possible, or unlikely CDI. A parametric accelerated failure time model was used to estimate the distribution of the incubation period. Results: Of 4,179 patients with negative enrollment cultures and no prior CDI diagnosis within 56 days, 107 (2.6%) were diagnosed as having CDI, including 19 (17.8%) with and 88 (82.2%) without prior detection of carriage. When the data were censored to only include participants with negative cultures collected within 14 days, the estimated median incubation period was 6 days with 25% and 75% of estimated incubation periods occurring within 3 and 12 days, respectively. The observed estimated incubation period did not differ significantly for patients classified as probable, possible, or unlikely CDI. Conclusion: Our findings are consistent with the previous studies that suggested the incubation period for CDI is typically less than 1 week and is less than 2 weeks in most cases.

Background: Verruconis gallopava is a dematiaceous and environmental commensal that rarely causes infection in humans. Human infections are typically observed in immunocompromised individuals. Clinical presentations range from localized infectious (skin and lung) to disseminated disease with a predilection for the central nervous system. Currently, no standardized guidelines exist for the treatment of V. gallopava . Most mold-active triazoles, except isavuconazole, have demonstrated in vitro antifungal activity against this pathogen. Case Summary: We present a case of an immunocompromised male who underwent heart transplantation with subsequent syndrome of chronic pneumonia. Imaging suggested an atypical pulmonary process prompting empiric initiation of isavuconazonium. Despite treatment, the patient’s condition worsened, and fungal culture from sputum and bronchoalveolar lavage both grew V. gallopava . His symptoms persisted, and he was transitioned to liposomal amphotericin B and eventually oral posaconazole (POS) with clinical and radiographic resolution of his presenting syndrome. Conclusion: This case highlights the limited experience and clinical failure of isavuconazonium as empiric therapy for V. gallopava . Transitioning to POS led to clinical improvement, suggesting its potential as a treatment option. Further experience is needed to establish optimal therapeutic strategies for this rare but serious infection.

Healthcare-facility–onset C.difficile LabID events are defined as positive stool samples collected >3 days after hospitalization. Using a definition of >72 hours, we found that 84 of 1013 cases (8.3%) identified as C. difficile LabID events were collected between 48 and 72 hours after admission.

Background: Medical University of South Carolina Health began vaccinating care team members December 15, 2020, with the Pfizer-BioNTech SARS-CoV-2 mRNA vaccine. We report surveillance data for cases diagnosed following vaccination. Methods: Care team members (CTMs) diagnosed with COVID-19 following SARS-CoV-2 vaccination were self-identified during online electronic contact-tracing surveys. Demographic data, symptoms, and dates of symptoms were recorded. CTMs testing positive at MUSC were linked to viral burden data from nasopharyngeal swabs tested on Abbott PCR platforms. Results: As of January 31, 2021, 111 CTMs tested positive for SARS-CoV-2 following vaccination: 99 and 12 after 1 and 2 doses, respectively, at medians of 10 days (range, 1–22) and 5 days (range, 1–16), respectively, from vaccination to testing. Of 2 cases that tested positive >14 days from dose 2, CTMs had symptom onset at 4 and 12 days from dose 2. Among CTMs reporting symptoms, 104 did so after a median of 7 days (mean 6.3, range −23 to +22) from vaccination to symptom onset, with 8 reporting symptoms before vaccination, 9 on the day of vaccination, and 3 CTMs at 1 day after vaccination, 6 CTMs at 2 days after vaccination, and 11 CTMs at 3 days after vaccination. Overall, 86 (78%) of 111 were female and 95 (86%) of 111 were white. The median age was 44 years (range, 22–71). Clinical job roles were most frequently nurses (n = 31, 28%), physicians or physician extenders (n = 19, 17%), and CTMs with no patient contact (n = 21, 19%). Assessment by the contact-tracing team assigned sources as household clusters (n = 22, 23%), local transmission (n = 21, 22%), occupational acquisition from coworkers (n = 11, 12%), travel related (n = 9, 10%), and unknown (n = 32, 34%). Only 32 (32%) CTMs were compliant with physical distancing. Among 104 CTMs reporting symptoms, cough (75%), headache (71%), rhinorrhea (63%), myalgia (60%), sore throat (48%), anosmia (44%), and subjective fever (40%) were the most commonly reported symptoms. Among 54 symptomatic CTMs with available viral-load data, the median and mean cycle numbers (Cn) were 19.98 and 21.91, respectively, for samples tested a median 3 days from symptom onset. Asymptomatic and symptomatic CTMs had a median Cn of 30.1 vs 20.9, respectively (p 20, with no significant effect seen by vaccine dose (Figure 1). Conclusions: Most COVID-19 cases following vaccination occurred in CTMs with infection incubating prior to vaccination. No significant attenuation of viral load is apparent among vaccinated CTMs with COVID-19, but asymptomatic CTMs diagnosed with COVID-19 following vaccination appear to have resolved infections. Our data reinforce the need to adhere to public health measures by people who have been vaccinated.Funding: NoDisclosures: None