Lower seroprevalence for SARS-CoV-2-specific antibodies among kidney transplant recipients compared to the general population in the city of Sao Paulo, Brazil.

BACKGROUND: Kidney transplant recipients have higher COVID-19 associated mortality compared to the general population. However, as only symptomatic patients seek medical attention, the current level of exposure, the main sources of acquisition, and the behavior of humoral immunity over time are poorly understood. METHODS: This cross-sectional prospective single-center study recruited kidney transplant recipients of any age living in Sao Paulo. A sample size of 401 patients was calculated considering the 17.2% seroprevalence in the municipality population from a published survey, a 95% confidence interval and an absolute error of 2%. RESULTS: Of the 2636 eligible patients, 416 were included. The seroprevalence for IgG anti-SARS-CoV-2 was 8.2%. Seroconversion rate decreased with increasing age, from 15.7% (18-35 years) to 8.3% (36-60 years) and 4.2% (>60 years, p = 0.042). Seropositivity among previously confirmed COVID-19 patients was 68.4%, followed by 9.4% in those with flu-like symptoms and only 4.6% among asymptomatic patients (p < 0.0001). Seroprevalence was significantly higher among patients reporting household contact (p = 0.018). Twenty-seven from the 34 IgG+ patients had a second test after 59 (IQR 50-63) days, and, in 33%, the IgG index became below the positivity threshold. CONCLUSIONS: In this cohort of kidney transplant recipients, the seroprevalence for IgG anti-SARS-CoV-2 was lower than that of the general population, decreased with ageing, and was associated with household contacts. In a considerable proportion of the patients, there was a significant decay in the IgG levels in a short period of time. Therefore, preventive strategies, such as prioritization for vaccination, should be urgently considered.

Donor-Derived Transmission of Cryptococcus gattii sensu lato in Kidney Transplant Recipients.

We describe cases of donor-derived transmission of Cryptococcus deuterogattii in 2 kidney transplant recipients in Brazil and published information on other cases. Prompt reduction of immunosuppression and initiation of antifungal therapy was required to successfully control the fungal infections and preserve engraftment.

Species diversity, antifungal susceptibility and phenotypic and genotypic characterisation of Exophiala spp. infecting patients in different medical centres in Brazil.

The Exophiala genus is responsible for many superficial and invasive infections resulting from black fungi. Identification of Exophiala at the species level is based on morphological observations complemented by molecular tests. The aim of this study was to identify 23 clinical isolates of Exophiala spp. and evaluate the antifungal susceptibility to seven different agents. Molecular identification was based on an analysis of ITS region of rDNA using genomic databases. The micromorphology was evaluated by microculture and scanning electron microscopy. The susceptibility tests were performed using the antifungal agents 5-fluorocytosine (5-FC), amphotericin B (AMB), itraconazole (ITC), voriconazole (VRC), posaconazole (PSC), caspofungin (CFG) and terbinafine (TRB). The ITS analysis identified 100% of the following isolates as: E. dermatitidis (8), E. xenobiotica (6), E. bergeri (4), E. oligosperma (3), E. spinifera (1) and E. mesophila (1). The antifungal susceptibility tests showed that the triazoles compounds were in vitro the most active agents against Exophiala. ITS sequencing enabled the accurate identification of the 23 tested isolates. The triazoles, particularly itraconazole and posaconazole, exhibited MIC values lower than AMB, CAS and 5-FC. Although the guidelines do not indicate AMB for treatment against Exophiala spp., this study showed activity for all of the tested species, except E. mesophila.

Squamous cell carcinoma derived from chronic chromoblastomycosis in Brazil.

BACKGROUND: Chromoblastomycosis (CBM) is a chronic fungal infection caused mainly by the melanized fungi Fonsecaea species. The chronic lesions may be predisposed to develop into cancer, the most serious complication of the disease. METHODS: In this report, 7 cases of squamous cell carcinoma (SCC) resulting from chronic CBM in patients from Maranhão in the Brazilian Amazon are described. RESULTS: The 7 patients presented with SCC that resulted from chronic CBM, caused by Fonsecaea species >10 years' duration. The malignant lesions occurred independent of the antifungal therapy and all patients underwent curative amputation, except for 1 patient who developed metastases in the inguinal and intra-abdominal lymph nodes and thigh muscles. A majority of previous reports have focused on the malignant transformation of CBM described in only 1 patient each. This is a first report describing a group of patients from a single Brazilian state. CONCLUSIONS: Here, we provide new epidemiologic data on malignant CBM lesions, an endemic disease that is seemingly neglected worldwide. We reinforce the idea that typically chronic lesions may be predisposed to turn malignant.

Fonsecaea pugnacius, a Novel Agent of Disseminated Chromoblastomycosis.

We report a fatal case of a chromoblastomycosis-like infection caused by a novel species of Fonsecaea in a 52-year-old immunocompetent Caucasian male from an area of chromoblastomycosis endemicity in Brazil. The patient had a 30-year history of slowly evolving, verrucous lesions on the right upper arm which gradually affected the entire arm, the left hemifacial area, and the nose. Subsequent dissemination to the brain was observed, which led to death of the patient. The internal transcribed spacer (ITS) and partial large subunit (LSU), BT2, and CDC42 genes of the isolates recovered from skin and brain were sequenced, confirming the novelty of the species. The species is clinically unique in causing brain abscesses secondary to chromoblastomycosis lesions despite the apparent intact immunity of the patient. Histopathologic appearances were very different, showing muriform cells in skin and hyphae in brain.

Molecular identification of melanised non-sporulating moulds: a useful tool for studying the epidemiology of phaeohyphomycosis.

Subcutaneous infections caused by melanised fungi have been increasingly reported among transplant patients, and these infections have the potential for blood and visceral dissemination. Some moulds, such as Mycelia sterilia, cannot grow and sporulate on different media, making their identification impossible by conventional methods. The fast and accurate identification of melanised fungi at the species level is important because species may have tropism to different organs and different susceptibilities to antifungal agents. Molecular tools have been reported to be helpful for the species identification of non-sporulating moulds. Our goal was to identify the species of M. sterilia isolates obtained from clinical samples of transplant patients using sequences of ITS and the D1/D2 regions of rDNA. Clinical samples were obtained from eight kidney transplant recipients who developed subcutaneous fungal infections. The diagnosis was confirmed by histopathology and conventional culture. Histopathology showed septated, melanised hyphae, and the cultures identified non-sporulating fungi. Therefore, the DNA from the M. sterilia isolates was subjected to PCR amplification and sequencing of the ITS and D1/D2 regions. Genus/species identification was obtained by comparison with gene banks. We obtained the following identifications: Alternaria sp. (2), Cochliobolus lunatus/Curvularia lunata (2), Cochliobolus hawaiiensis/Bipolaris hawaiiensis (1), Ochroconis sp. (1), Medicocopsis romeroi/Pyrenochaeta romeroi (1) and Nigrograna mackinnonii/Pyrenochaeta mackinnonii (1).

The Full Spectrum of COVID-19 Development and Recovery Among Kidney Transplant Recipients.

BACKGROUND: Coronavirus disease 2019 (COVID-19) fatality rate is high among kidney transplant recipients. Among survivors, kidney outcomes, seroconversion, and persistence of viral shedding are unexplored. METHODS: Single-center prospective cohort study including data from kidney transplant recipients with confirmed COVID-19 between March 20, 2020 and July 31, 2020. Outcomes were adjudicated until August 31, 2020 or the date of death. RESULTS: There were 491 patients with COVID-19 among the 11 875 recipients in follow-up. The majority were middle aged with ≥1 comorbidities. Thirty-one percent were treated at home, and 69% required hospitalization. Among the hospitalized, 61% needed intensive care, 75% presented allograft dysfunction, and 46% needed dialysis. The overall 28-day fatality rate was 22% and among hospitalized patients it was 41%. Age (odds ratio, 3.08; 95% confidence interval, 1.86-5.09), diabetes mellitus (odds ratio, 1.69; 95% confidence interval, 1.06-2.72), and cardiac disease (odds ratio, 2.00; 95% confidence interval, 1.09-3.68) were independent factors for death. Among the 351 survivors, 19% sustained renal graft dysfunction, and there were 13 (4%) graft losses. Biopsy (n = 20) findings were diverse but decisive to guide treatment and estimate prognosis. Seroconversion was observed in 79% of the survivors and was associated with disease severity. Persistence of viral shedding was observed in 21% of the patients without detectable clinical implications. CONCLUSIONS: This prospective cohort analysis confirms the high 28-day fatality rate of COVID-19, associated primarily with age and comorbidities. The high incidence of allograft dysfunction was associated with a wide range of specific histologic lesions and high rates of sequelae and graft loss. Seroconversion was high and the persistence of viral shedding deserves further studies.

Molecular Epidemiology of Agents of Human Chromoblastomycosis in Brazil with the Description of Two Novel Species.

The human mutilating disease chromoblastomycosis is caused by melanized members of the order Chaetothyriales. To assess population diversity among 123 clinical strains of agents of the disease in Brazil we applied sequencing of the rDNA internal transcribed spacer region, and partial cell division cycle and ß-tubulin genes. Strains studied were limited to three clusters divided over the single family Herpotrichiellaceae known to comprise agents of the disease. A Fonsecaea cluster contained the most important agents, among which F. pedrosoi was prevalent with 80% of the total set of strains, followed by 13% for F. monophora, 3% for F. nubica, and a single isolate of F. pugnacius. Additional agents, among which two novel species, were located among members of the genus Rhinocladiella and Cyphellophora, with frequencies of 3% and 1%, respectively.