Mycobacterium abscessus: a rare cause of vascular graft infection.

Prosthetic vascular graft infection (PVGI) following vascular reconstructive surgery is an uncommon but serious complication and is associated with high morbidity as well as mortality rate. Staphylococcal species are the most common organisms causing PVGI. Mycobacterium abscessus is a very rare cause of PVGI and poses a significant diagnostic and management dilemma. To the best of our knowledge, we report the third documented case of M. abscessus vascular graft infection that was diagnosed with 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scan and treated successfully.

Atovaquone for treatment of COVID-19: A prospective randomized, double-blind, placebo-controlled clinical trial.

Background: An in silico screen was performed to identify FDA approved drugs that inhibit SARS-CoV-2 main protease (Mpro), followed by in vitro viral replication assays, and in vivo pharmacokinetic studies in mice. These studies identified atovaquone as a promising candidate for inhibiting viral replication. Methods: A 2-center, randomized, double-blind, placebo-controlled trial was performed among patients hospitalized with COVID-19 infection. Enrolled patients were randomized 2:1 to atovaquone 1500 mg BID versus matched placebo. Patients received standard of care treatment including remdesivir, dexamethasone, or convalescent plasma as deemed necessary by the treating team. Saliva was collected at baseline and twice per day for up to 10 days for RNA extraction for SARS-CoV-2 viral load measurement by quantitative reverse-transcriptase PCR. The primary outcome was the between group difference in log-transformed viral load (copies/mL) using a generalized linear mixed-effect models of repeated measures from all samples. Results: Of the 61 patients enrolled; 41 received atovaquone and 19 received placebo. Overall, the population was predominately male (63%) and Hispanic (70%), with a mean age of 51 years, enrolled a mean of 5 days from symptom onset. The log10 viral load was 5.25 copies/mL vs. 4.79 copies/mL at baseline in the atovaquone vs. placebo group. Change in viral load did not differ over time between the atovaquone plus standard of care arm versus the placebo plus standard of care arm. Pharmacokinetic (PK) studies of atovaquone plasma concentration demonstrated a wide variation in atovaquone levels, with an inverse correlation between BMI and atovaquone levels, (Rho -0.45, p = 0.02). In post hoc analysis, an inverse correlation was observed between atovaquone levels and viral load (Rho -0.54, p = 0.005). Conclusion: In this prospective, randomized, placebo-controlled trial, atovaquone did not demonstrate evidence of enhanced SARS-CoV-2 viral clearance compared with placebo. However, based on the observed inverse correlation between atovaquone levels and viral load, additional PK-guided studies may be warranted to examine the antiviral effect of atovaquone in COVID-19 patients.

Efficacy of interferon beta-1a plus remdesivir compared with remdesivir alone in hospitalised adults with COVID-19: a double-bind, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Functional impairment of interferon, a natural antiviral component of the immune system, is associated with the pathogenesis and severity of COVID-19. We aimed to compare the efficacy of interferon beta-1a in combination with remdesivir compared with remdesivir alone in hospitalised patients with COVID-19. METHODS: We did a double-blind, randomised, placebo-controlled trial at 63 hospitals across five countries (Japan, Mexico, Singapore, South Korea, and the USA). Eligible patients were hospitalised adults (aged ≥18 years) with SARS-CoV-2 infection, as confirmed by a positive RT-PCR test, and who met one of the following criteria suggestive of lower respiratory tract infection: the presence of radiographic infiltrates on imaging, a peripheral oxygen saturation on room air of 94% or less, or requiring supplemental oxygen. Patients were excluded if they had either an alanine aminotransferase or an aspartate aminotransferase concentration more than five times the upper limit of normal; had impaired renal function; were allergic to the study product; were pregnant or breast feeding; were already on mechanical ventilation; or were anticipating discharge from the hospital or transfer to another hospital within 72 h of enrolment. Patients were randomly assigned (1:1) to receive intravenous remdesivir as a 200 mg loading dose on day 1 followed by a 100 mg maintenance dose administered daily for up to 9 days and up to four doses of either 44 µg interferon beta-1a (interferon beta-1a group plus remdesivir group) or placebo (placebo plus remdesivir group) administered subcutaneously every other day. Randomisation was stratified by study site and disease severity at enrolment. Patients, investigators, and site staff were masked to interferon beta-1a and placebo treatment; remdesivir treatment was given to all patients without masking. The primary outcome was time to recovery, defined as the first day that a patient attained a category 1, 2, or 3 score on the eight-category ordinal scale within 28 days, assessed in the modified intention-to-treat population, defined as all randomised patients who were classified according to actual clinical severity. Safety was assessed in the as-treated population, defined as all patients who received at least one dose of the assigned treatment. This trial is registered with ClinicalTrials.gov, NCT04492475. FINDINGS: Between Aug 5, 2020, and Nov 11, 2020, 969 patients were enrolled and randomly assigned to the interferon beta-1a plus remdesivir group (n=487) or to the placebo plus remdesivir group (n=482). The mean duration of symptoms before enrolment was 8·7 days (SD 4·4) in the interferon beta-1a plus remdesivir group and 8·5 days (SD 4·3) days in the placebo plus remdesivir group. Patients in both groups had a time to recovery of 5 days (95% CI not estimable) (rate ratio of interferon beta-1a plus remdesivir group vs placebo plus remdesivir 0·99 [95% CI 0·87-1·13]; p=0·88). The Kaplan-Meier estimate of mortality at 28 days was 5% (95% CI 3-7%) in the interferon beta-1a plus remdesivir group and 3% (2-6%) in the placebo plus remdesivir group (hazard ratio 1·33 [95% CI 0·69-2·55]; p=0·39). Patients who did not require high-flow oxygen at baseline were more likely to have at least one related adverse event in the interferon beta-1a plus remdesivir group (33 [7%] of 442 patients) than in the placebo plus remdesivir group (15 [3%] of 435). In patients who required high-flow oxygen at baseline, 24 (69%) of 35 had an adverse event and 21 (60%) had a serious adverse event in the interferon beta-1a plus remdesivir group compared with 13 (39%) of 33 who had an adverse event and eight (24%) who had a serious adverse event in the placebo plus remdesivir group. INTERPRETATION: Interferon beta-1a plus remdesivir was not superior to remdesivir alone in hospitalised patients with COVID-19 pneumonia. Patients who required high-flow oxygen at baseline had worse outcomes after treatment with interferon beta-1a compared with those given placebo. FUNDING: The National Institute of Allergy and Infectious Diseases (USA).

Central nervous system histoplasmosis: Multicenter retrospective study on clinical features, diagnostic approach and outcome of treatment.

Central nervous system (CNS) involvement occurs in 5 to 10% of individuals with disseminated histoplasmosis. Most experience has been derived from small single center case series, or case report literature reviews. Therefore, a larger study of central nervous system (CNS) histoplasmosis is needed in order to guide the approach to diagnosis, and treatment.A convenience sample of 77 patients with histoplasmosis infection of the CNS was evaluated. Data was collected that focused on recognition of infection, diagnostic techniques, and outcomes of treatment.Twenty nine percent of patients were not immunosuppressed. Histoplasma antigen, or anti-Histoplasma antibodies were detected in the cerebrospinal fluid (CSF) in 75% of patients. One year survival was 75% among patients treated initially with amphotericin B, and was highest with liposomal, or deoxycholate formulations. Mortality was higher in immunocompromised patients, and patients 54 years of age, or older. Six percent of patients relapsed, all of whom had the acquired immunodeficiency syndrome (AIDS), and were poorly adherent with treatment.While CNS histoplasmosis occurred most often in immunocompromised individuals, a significant proportion of patients were previously, healthy. The diagnosis can be established by antigen, and antibody testing of the CSF, and serum, and antigen testing of the urine in most patients. Treatment with liposomal amphotericin B (AMB-L) for at least 1 month; followed by itraconazole for at least 1 year, results in survival among the majority of individuals. Patients should be followed for relapse for at least 1 year, after stopping therapy.

Disseminated Nocardiosis Associated with Treatment with Infliximab in a Patient with Ulcerative Colitis.

BACKGROUND Opportunistic infections may occur when patients with inflammatory bowel disease (IBD) are treated with tumor necrosis factor (TNF)-alpha inhibitors. With the increasing use of new immunosuppressant drugs, the incidence of opportunistic or atypical infections is also increasing, including with Nocardia spp. A high level of awareness of atypical infections is warranted in immunosuppressed patients. CASE REPORT A 57-year-old female African American, with a past medical history of ulcerative colitis (UC) and arthritis, was treated with infliximab and prednisone. She presented to the emergency department with acute onset of chest pain, shortness of breath, and a two-week history of a productive cough. Examination showed hypoxia, tachypnea, decreased and coarse bilateral breath sounds, and fluctuant, tender, erythematous masses on her trunk and groin. Laboratory investigations showed a leukocytosis with a left shift. She was initially treated for presumed community-acquired pneumonia (CAP). However, blood cultures grew Nocardia farcinica and treatment with trimethoprim-sulfamethoxazole (TMP-SMX) was begun, which was complicated by severe symptomatic hyponatremia. Following recovery from infection and resolution of the hyponatremia, the patient was discharged to a senior care facility, but with continued treatment with TMP-SMX. CONCLUSIONS To our knowledge, this is the first case of disseminated nocardiosis associated with infliximab treatment in a patient with ulcerative colitis. As with other forms of immunosuppressive therapy, patients who are treated with infliximab should be followed closely due to the increased risk of atypical infections. When initiating antibiotic therapy, careful monitoring of possible side effects should be done.

Cellular immune response in HIV-infected patients with histoplasmosis.

The relationship of immunity to Histoplasma capsulatum and CD4 count in HIV-1-infected patients is unknown. Samples of blood from people with HIV infection and from HIV-negative volunteers were assessed for immune responsiveness to the histoplasmin antigen using proliferation and interferon-gamma production as indicators of immunity. Results of histoplasmin skin tests, lymphoproliferative responses (LPR), and interferon-gamma production were positive in 9 of 20 (45%) HIV-negative controls, and in vitro measurements agreed highly with skin test reactivity. Among HIV-1-infected patients with recent histoplasmosis, skin test results were positive in none, LPR results were positive in 14%, and interferon-gamma production in 18%. Among HIV-1-infected patients with CD4 counts between 200 and 500 cells/mm(3), LPR was positive in 8% and interferon-gamma production in 33%, and among those with CD4 counts >500 cells/mm(3), LPR was positive in 31% and interferon-gamma production in 46%. In conclusion, immune responsiveness to H. capsulatum was depressed in HIV-1-infected persons with CD4 counts between 200 and 500 cells/mm(3), but approached normal in those with CD4 counts >500 cells/mm(3).