Assessment of Anti-SARS-CoV-2 antibody levels among university students vaccinated with different COVID-19 primary and booster doses - fall 2021, Wisconsin.

BACKGROUND: University students commonly received COVID-19 vaccinations before returning to U.S. campuses in the Fall of 2021. Given likely immunologic variation among students based on differences in type of primary series and/or booster dose vaccine received, we conducted serologic investigations in September and December 2021 on a large university campus in Wisconsin to assess anti-SARS-CoV-2 antibody levels. METHODS: We collected blood samples, demographic information, and COVID-19 illness and vaccination history from a convenience sample of students. Sera were analyzed for both anti-spike (anti-S) and anti-nucleocapsid (anti-N) antibody levels using World Health Organization standardized binding antibody units per milliliter (BAU/mL). Levels were compared across categorical primary COVID-19 vaccine series received and binary COVID-19 mRNA booster status. The association between anti-S levels and time since most recent vaccination dose was estimated by mixed-effects linear regression. RESULTS: In total, 356 students participated, of whom 219 (61.5%) had received a primary vaccine series of Pfizer-BioNTech or Moderna mRNA vaccines and 85 (23.9%) had received vaccines from Sinovac or Sinopharm. Median anti-S levels were significantly higher for mRNA primary vaccine series recipients (2.90 and 2.86 log [BAU/mL], respectively), compared with those who received Sinopharm or Sinovac vaccines (1.63 and 1.95 log [BAU/mL], respectively). Sinopharm and Sinovac vaccine recipients were associated with a significantly faster anti-S decline over time, compared with mRNA vaccine recipients (P <.001). By December, 48/172 (27.9%) participants reported receiving an mRNA COVID-19 vaccine booster, which reduced the anti-S antibody discrepancies between primary series vaccine types. CONCLUSIONS: Our work supports the benefit of heterologous boosting against COVID-19. COVID-19 mRNA vaccine booster doses were associated with increases in anti-SARS-CoV-2 antibody levels; following an mRNA booster dose, students with both mRNA and non-mRNA primary series receipt were associated with comparable levels of anti-S IgG.

The Role of Isavuconazonium Sulphate for the Treatment of Blastomycosis: A Case Series and Antifungal Susceptibility.

Background: Blastomyces spp, the etiologic agents of blastomycosis, are endemic dimorphic fungi that require prolonged antifungal therapy, which can be complicated by adverse drug effects. Isavuconazonium sulphate (ISA) is a triazole with in vitro and in vivo activity against Blastomyces spp, but there is a paucity of clinical data supporting its use for treatment of blastomycosis. Methods: This retrospective case series identified 14 patients with blastomycosis at least partially treated with ISA at the University of Wisconsin between 2015 and 2019. Treatment duration and outcomes were documented. In addition, 29 clinical isolates of Blastomyces spp between 2004 and 2017 were tested for minimum inhibitory concentrations against ISA and other antifungals. Results: Fourteen patients were treated with a median of 255 days of ISA accounting for 68% of total therapy. Half (7 of 14) of the patients were immunocompromised, 11 of 14 (79%) were proven cases of blastomycosis, 7 of 14 (50%) had central nervous system (CNS) involvement, and 11 of 14 (79%) were cured. Antifungal susceptibility testing showed a consistently low minimum inhibitory concentration to ISA ≤ 0.015 mcg/mL. Conclusions: This case series supports the efficacy and safety for ISA in the treatment of blastomycosis with or without CNS disseminated, especially when alternative triazoles cannot be used.

A cohort study measuring SARS-CoV-2 seroconversion and serial viral testing in university students.

BACKGROUND: To improve understanding of the antibody response to SARS-CoV-2 infection, we examined seroprevalence, incidence of infection, and seroconversion among a cohort of young adults living on university campuses during the fall of 2020. METHODS: At the beginning (semester start) and end (semester end) of an 11-week period, serum collected from 107 students was tested using the qualitative Abbott Architect SARS-CoV-2 IgG and AdviseDx SARS-CoV-2 IgG II assays. Results were matched to interim weekly surveillance viral testing and symptom data. RESULTS: With the SARS-CoV-2 IgG assay, 15 (14.0%) students were seropositive at semester start; 29 (27.1%) students were seropositive at semester end; 10 (9.3%) were seropositive at both times. With the AdviseDx SARS-CoV-2 IgG II assay, 17 (16.3%) students were seropositive at semester start, 37 (35.6%) were seropositive at semester end, and 16 (15.3%) were seropositive at both times. Overall, 23 students (21.5%) had positive viral tests during the semester. Infection was identified by serial testing in a large majority of individuals who seroconverted using both assays. Those seropositive at semester end more frequently reported symptomatic infections (56.5%) than asymptomatic infections (30.4%). CONCLUSION: Differences between antibody targets were observed, with more declines in antibody index values below the threshold of positivity with the anti-nucleocapsid assay compared to the anti-spike assay. Serology testing, combined with serial viral testing, can detect seroconversions, and help understand the potential correlates of protection provided by antibodies to SARS-CoV-2.

Performance of Repeat BinaxNOW Severe Acute Respiratory Syndrome Coronavirus 2 Antigen Testing in a Community Setting, Wisconsin, November 2020-December 2020.

Repeating the BinaxNOW antigen test for severe acute respiratory syndrome coronavirus 2 using 2 groups of readers within 30 minutes resulted in high concordance (98.9%) in 2110 encounters. Same-day repeat antigen testing did not significantly improve test sensitivity (77.2% to 81.4%) while specificity remained high (99.6%).

Clinical Manifestations and Outcomes in Immunocompetent and Immunocompromised Patients With Blastomycosis.

BACKGROUND: Blastomyces is a dimorphic fungus that infects persons with or without underlying immunocompromise. To date, no study has compared the clinical features and outcomes of blastomycosis between immunocompromised and immunocompetent persons. METHODS: A retrospective study of adult patients with proven blastomycosis from 2004-2016 was conducted at the University of Wisconsin. Epidemiology, clinical features, and outcomes were analyzed among solid-organ transplantation (SOT) recipients, persons with non-SOT immunocompromise (non-SOT IC), and persons with no immunocompromise (NIC). RESULTS: A total of 106 cases met the inclusion criteria including 74 NIC, 19 SOT, and 13 non-SOT IC (malignancy, HIV/AIDS, idiopathic CD4+ lymphopenia). The majority of patients (61.3%) had at least 1 epidemiologic risk factor for acquisition of Blastomyces. Pneumonia was the most common manifestation in all groups; however, immunocompromised patients had higher rates of acute pulmonary disease (P = .03), more severe infection (P = .007), respiratory failure (P = .010), and increased mortality (P = .02). Receipt of SOT primarily accounted for increased severity, respiratory failure, and mortality in immunosuppressed patients. SOT recipients had an 18-fold higher annual incidence of blastomycosis than the general population. The rate of disseminated blastomycosis was similar among NIC, SOT, and non-SOT IC. Relapse rates were low (5.3-7.7%). CONCLUSIONS: Immunosuppression had implications regarding the acuity, severity, and respiratory failure. The rate of dissemination was similar across the immunologic spectrum, which is in sharp contrast to other endemic fungi. This suggests that pathogen-related factors have a greater influence on dissemination for blastomycosis than immune defense.

Attempted Isolation of Cryptococcus Species and Incidental Isolation of Exophiala dermatitidis from Human Oral Cavities.

Recent molecular studies suggest that Cryptococcus may inhabit the normal human mouth. We attempted to isolate Cryptococcus from 21 adult non-acutely ill patients and 40 volunteer medical and non-medical staff in Southeastern Wisconsin, USA. An upper lip sulcus culture and an oral rinse specimen were inoculated separately onto Staib (birdseed) agar containing chloramphenicol and incubated in gas impermeable zip lock bags at 35 °C. No cryptococci were grown from any of the 122 samples from the 61 subjects. Both specimens from a woman with no risk factors for fungal disease yielded a black yeast at 4 days on Staib agar. This isolate was shown to be Exophiala dermatitidis by colony and microscopic morphology, analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and sequencing through the internal transcribed spacer ribosomal RNA gene. This appears to be a novel isolation of E. dermatitidis from the oral cavity of a generally healthy human.

Urine Antigen Testing is Equally Sensitive to B. dermatitidis and B. gilchristii Infections.

INTRODUCTION: Blastomycosis is endemic in Wisconsin with Blastomyces dermatitidis and B. gilchristii responsible for infections. Urine antigen testing is a non-invasive diagnostic method for blastomycosis with up to 93% test sensitivity. However, the test's sensitivity has not been evaluated with relationship to B. gilchristii infections. METHODS: We aimed to assess physician use of the urine antigen assay and its sensitivity to B. gilchristii and B. dermatitidis infections in a retrospective study. Culture confirmed clinical cases of blastomycosis from 2008-2016 were identified within Marshfield Clinic Health System (MCHS) and UW Hospital and Clinics (UWHC) medical records. Clinical data were abstracted from each medical record and included the following: patient demographics, presence of immune compromising and underlying medical conditions, treatment drugs, presence of isolated pulmonary or disseminated disease, death, urine antigen testing, timeframe of testing, and quantitative test values (EIA units or ng/mL). RESULTS: A total of 140 blastomycosis cases were included in this study, with MCHS contributing 114 cases to the study and UWHC contributing 26 cases. The majority of UWHC cases (n=22; 85%) were caused by B. dermatitidis and the majority of MCHS cases (n=73; 64%) were caused by B. gilchristii. UWHC physicians were significantly more likely to treat with multiple drugs during the course of infection and were more likely to prescribe amphotericin B and voriconazole. Urine antigen testing was more frequently used at UWHC (n=24; 92%) than MCHS (n=51; 45%; P < 0.00001). In this study, the urine antigen assay demonstrated 79% sensitivity. Sensitivity was significantly associated with the timeframe of testing (P < 0.05), with most true positive urine antigen tests (83%) being performed ≤ 7 days from diagnosis. In this study, the urine antigen assay was capable of detecting both B. dermatitidis and B. gilchristii at about equal sensitivity. Urine antigen concentration (ng/mL) trended higher in B. dermatitidis infections. CONCLUSION: This study found that the urine antigen assay is capable of detecting both species of Blastomyces at about the same sensitivity. We recommend continued use of the urine antigen assay for diagnosis of blastomycosis and recommend that the assay be used early in the diagnostic process to minimize the chance of false negative results.

An Unusual Case of Actinomucor elegans: A Challenging Diagnosis.

BACKGROUND Actinomucor elegans is an unusual cause of mucormycosis and can be difficult to identify by conventional methods. Mucormycosis has a very high mortality rate, especially among immunocompromised individuals. Due to the morbid and progressive nature of opportunistic fungal infections, early diagnosis is paramount for effective disease management. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI) and Sanger sequencing are useful methods for rapid diagnosis of unusual fungal pathogens. CASE REPORT We report a fatal case of mucormycosis caused by A. elegans in an immunocompromised man. The pathogen was isolated from a large nasal septal black eschar that developed rapidly during tooth extraction in a patient with myelodysplastic syndrome and diabetes mellitus. After unsuccessful identification by conventional methods, A. elegans was identified using MALDI and Sanger sequencing. CONCLUSIONS Diagnosing fungal organisms poses many difficulties, but amidst the technological evolution in pathogen identification, there are useful methods for rapid identification, including MALDI and sequencing. With these powerful tools, earlier diagnosis will give health professionals an advantage against potentially fatal fungal infections.

Two Cases Illustrating the Diagnostic Challenge of Pediatric Blastomycosis Presenting as Osteomyelitis.

Blastomyces dermatitidis is a dimorphic fungus endemic to the United States and Canada. Although both Histoplasma and Blastomyces are found in similar geographic regions, Blastomyces is many times more likely to cause dissemination in the immunocompetent host, frequently involving the bone. However, given the indolent nature of this fungal infection and more prevalent bacterial etiologies of osteomyelitis, diagnosis and treatment are often significantly delayed. We review 2 pediatric cases that initially presented with isolated orthopedic symptoms without documented fever or pulmonary complaints, although both had signs of pulmonary infection on imaging. These cases demonstrate the importance of a high level of suspicion as well as appropriate diagnostic workup, including surgical pathology with fungal stains, when evaluating osteomyelitis in patients exposed to a Blastomyces-endemic region.

Strengthening Public Health in Wisconsin Through the Wisconsin Clinical Laboratory Network.

The Wisconsin Clinical Laboratory Network (WCLN) at the University of Wisconsin-Madison is a partnership of 138 clinical and public health laboratories (as of February 2019) coordinated by the Wisconsin State Laboratory of Hygiene. This article describes the WCLN, its current activities, and lessons learned through this partnership. A laboratory technical advisory group, which consists of representatives from clinical laboratories, provides clinical laboratory perspective to the WCLN and fosters communication among laboratories. Activities and resources available through the WCLN include annual regional meetings, annual technical workshops, webinars, an email listserv, laboratory informational messages, in-person visits by a WCLN coordinator to clinical laboratories, and laboratory-based surveillance data and summaries distributed by the Wisconsin State Laboratory of Hygiene. One challenge to maintaining the WCLN is securing continual funding for network activities. Key lessons learned from this partnership of more than 20 years include the importance of in-person meetings, the clinical perspective of the laboratory technical advisory group, and providing activities and resources to clinical laboratories to foster sharing of data and clinical specimens for public health surveillance and outbreak response.

The Shock of Strep: Rapid Deaths Due to Group a Streptococcus.

Streptococcus pyogenes, also known as group A beta-hemolytic strep, is a Gram positive coccus responsible for several million infections every year. The types of infections vary widely from pharyngitis to myositis, but all can advance to severe life threatening invasive disease. Of those infected, approximately 1100 to 1600 people die each year due to invasive disease. Why certain individuals contract severe infections is not known, but many strains of Streptococcus pyogenes are known to produce toxins and superantigens. Invasive Streptococcus pyogenes infections have been shown to cause significant morbidity and rapid mortality. In many cases, patients expire before full antemortem testing can be performed, causing physicians and families to look to forensic pathologists for answers. Understanding the pathogenesis of invasive group A strep infections, relevant gross and microscopic findings, and proper culturing techniques is critical for forensic pathologists to diagnosis this condition and assist in the education and protection of the communities they serve.

Serratia marcescens Bacteremia: Nosocomial Cluster Following Narcotic Diversion.

OBJECTIVE To describe the investigation and control of a cluster of Serratia marcescens bacteremia in a 505-bed tertiary-care center. METHODS Cluster cases were defined as all patients with S. marcescens bacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio. RESULTS In total, 6 patients developed S. marcescens bacteremia within 48 hours after admission within the above period. Of these, 5 patients had identical Serratia isolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employee's job was terminated. CONCLUSION Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting. Infect Control Hosp Epidemiol 2017;38:1027-1031.

First described case of prosthetic joint infection with Clostridium disporicum.

An orthopedic hardware infection with Clostridium disporicum is described. C. disporicum is a gram positive anaerobic bacillus which can contain two subterminal spores. C. disporicum had not previously been reported in musculoskeletal infections. Gram stains demonstrating gram positive bacilli with two subterminal spores should alert practitioners to the possibility of C. disporicum infection.

Blastomycosis in Wisconsin: Beyond the Outbreaks.

In the summer of 2015, many individuals visiting the Little Wolf River in Waupaca County were exposed to the pathogenic fungus, Blastomyces. Over time, 59 confirmed and 39 probable cases were reported to the Wisconsin Department of Health Services (W-DHS), making this one of the largest outbreaks in recent state history. Though most instances of blastomycosis are not associated with common source outbreaks, cases such as this highlight the need for vigilance regarding this preventable cause of death. In the state of Wisconsin, an average of 118.6 cases (range, 84-174) of confirmed blastomycosis are diagnosed annually; the majority of these cases are sporadic rather than outbreak-associated. In the current study, we review characteristics of blastomycosis cases diagnosed at our academic medical center, as well as examine statewide W-DHS data, in order to familiarize pathologists with the epidemiologic and histologic characteristics of this disease.

Macrolide and Clindamycin Resistance in Group a Streptococci Isolated From Children With Pharyngitis.

Group A streptococcus (GAS) is responsible for 15%-30% of cases of acute pharyngitis in children. Macrolides such as azithromycin have become popular for treating GAS pharyngitis. We report macrolide resistance rates in a primary care setting in our geographic area over the past 5 years and discuss the implications of resistance in making treatment decisions. Throat swabs were collected from children with pharyngitis from May 2011 to May 2015 in a primary care setting in Madison, Wisconsin. Susceptibility testing was performed for erythromycin and clindamycin using the Kirby-Bauer disk diffusion method. GAS was identified on 143 throat cultures. Overall, 15% of GAS isolates demonstrated nonsusceptibility for both clindamycin and erythromycin. Inducible resistance (positive D-test) was detected in 17 isolates (12%). The rate of detection of nonsusceptibility in each year of the study did not change over time. Azithromycin should only be used for patients with pharyngitis and substantial manifestations of penicillin hypersensitivity and when used, susceptibility testing should always be performed.

Fungal Mimicry of a Mammalian Aminopeptidase Disables Innate Immunity and Promotes Pathogenicity.

Systemic fungal infections trigger marked immune-regulatory disturbances, but the mechanisms are poorly understood. We report that the pathogenic yeast of Blastomyces dermatitidis elaborates dipeptidyl-peptidase IVA (DppIVA), a close mimic of the mammalian ectopeptidase CD26, which modulates critical aspects of hematopoiesis. We show that, like the mammalian enzyme, fungal DppIVA cleaved C-C chemokines and GM-CSF. Yeast producing DppIVA crippled the recruitment and differentiation of monocytes and prevented phagocyte activation and ROS production. Silencing fungal DppIVA gene expression curtailed virulence and restored recruitment of CCR2(+) monocytes, generation of TipDC, and phagocyte killing of yeast. Pharmacological blockade of DppIVA restored leukocyte effector functions and stemmed infection, while addition of recombinant DppIVA to gene-silenced yeast enabled them to evade leukocyte defense. Thus, fungal DppIVA mediates immune-regulatory disturbances that underlie invasive fungal disease. These findings reveal a form of molecular piracy by a broadly conserved aminopeptidase during disease pathogenesis.

Calnexin induces expansion of antigen-specific CD4(+) T cells that confer immunity to fungal ascomycetes via conserved epitopes.

Fungal infections remain a threat due to the lack of broad-spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown but conserved antigen. Using transgenic CD4(+) T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae, and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes, including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats, induces expansion of calnexin-specific CD4(+) T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4(+) T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogenicity and conservation of calnexin make this fungal protein a promising vaccine target.

The unappreciated intracellular lifestyle of Blastomyces dermatitidis.

Blastomyces dermatitidis, a dimorphic fungus and the causative agent of blastomycosis, is widely considered an extracellular pathogen, with little evidence for a facultative intracellular lifestyle. We infected mice with spores, that is, the infectious particle, via the pulmonary route and studied intracellular residence, transition to pathogenic yeast, and replication inside lung cells. Nearly 80% of spores were inside cells at 24 h postinfection with 10(4) spores. Most spores were located inside of alveolar macrophages, with smaller numbers in neutrophils and dendritic cells. Real-time imaging showed rapid uptake of spores into alveolar macrophages, conversion to yeast, and intracellular multiplication during in vitro coculture. The finding of multiple yeast in a macrophage was chiefly due to intracellular replication rather than multiple phagocytic events or fusion of macrophages. Depletion of alveolar macrophages curtailed infection in mice infected with spores and led to a 26-fold reduction in lung CFU by 6 d postinfection versus nondepleted mice. Phase transition of the spores to yeast was delayed in these depleted mice over a time frame that correlated with reduced lung CFU. Spores cultured in vitro converted to yeast faster in the presence of macrophages than in medium alone. Thus, although advanced B. dermatitidis infection may exhibit extracellular residence in tissue, early lung infection with infectious spores reveals its unappreciated facultative intracellular lifestyle.