Emergence of zoonotic sporotrichosis in Brazil: a genomic epidemiology study.

BACKGROUND: Zoonotic sporotrichosis is a neglected fungal disease, whereby outbreaks are primarily driven by Sporothrix brasiliensis and linked to cat-to-human transmission. To understand the emergence and spread of sporotrichosis in Brazil, the epicentre of the current epidemic in South America, we aimed to conduct whole-genome sequencing (WGS) to describe the genomic epidemiology. METHODS: In this genomic epidemiology study, we included Sporothrix spp isolates from sporotrichosis cases from Brazil, Colombia, and the USA. We conducted WGS using Illumina NovaSeq on isolates collected by three laboratories in Brazil from humans and cats with sporotrichosis between 2013 and 2022. All isolates that were confirmed to be Sporothrix genus by internal transcribed spacer or beta-tubulin PCR sequencing were included in this study. We downloaded eight Sporothrix genome sequences from the National Center for Biotechnology Information (six from Brazil, two from Colombia). Three Sporothrix spp genome sequences from the USA were generated by the US Centers for Disease Control and Prevention as part of this study. We did phylogenetic analyses and correlated geographical and temporal case distribution with genotypic features of Sporothrix spp isolates. FINDINGS: 72 Sporothrix spp isolates from 55 human and 17 animal sporotrichosis cases were included: 67 (93%) were from Brazil, two (3%) from Colombia, and three (4%) from the USA. Cases spanned from 1999 to 2022. Most (61 [85%]) isolates were S brasiliensis, and all were reported from Brazil. Ten (14%) were Sporothrix schenckii and were reported from Brazil, USA, and Colombia. For S schenckii isolates, two distinct clades were observed wherein isolates clustered by geography. For S brasiliensis isolates, five clades separated by more than 100 000 single-nucleotide polymorphisms were observed. Among the five S brasiliensis clades, clades A and C contained isolates from both human and cat cases, and clade A contained isolates from six different states in Brazil. Compared with S brasiliensis isolates, larger genetic diversity was observed among S schenckii isolates from animal and human cases within a clade. INTERPRETATION: Our results suggest that the ongoing epidemic driven by S brasiliensis in Brazil represents several, independent emergence events followed by animal-to-animal and animal-to human transmission within and between Brazilian states. These results describe how S brasiliensis can emerge and spread within a country. FUNDING: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil; the São Paulo Research Foundation; Productivity in Research fellowships by the National Council for Scientific and Technological Development, and Ministry of Science and Technology of Brazil.

Is positron emission tomography/magnetic resonance imaging a reliable tool for detecting vascular activity in treated childhood-onset Takayasu's arteritis? A multicentre study.

OBJECTIVES: Toassess whether 18F-fluordeoxiglucose (18F-FDG) PET/MRI) with angiographic sequences can contribute to detecting vessel wall inflammation in patients with childhood-onset Takayasu's arteritis (c-TA) under immunosuppressive therapy. METHODS: A three-centre cross-sectional study was conducted. 18F-FDG PET/MRI scans were performed in c-TA patients and in oncologic patients, who served as the control group. Clinical and laboratory characteristics were also analysed. RESULTS: Seventeen c-TA patients (65% females) between the ages of 6 and 21 years with a mean disease duration of 9.4 years were recruited. Only one patient presented clinical disease activity and six (35.6%) had increased ESR and/or CRP levels. The most frequent magnetic resonance angiography (MRA) findings were stenosis and thickening, observed in 82.4 and 70.6% of c-TA patients, respectively. 18F-FDG PET revealed 18F-FDG uptake greater than the liver in at least one arterial segment in 15 (88.2%) patients in a qualitative analysis and a median maximum standardized uptake value (SUVmax) of 3.22 (interquartile range 2.76-3.69) in a semi-quantitative analysis. c-TA patients presented significantly higher SUVmax values than oncologic patients (P < 0.001). A positive correlation between SUVmax and CRP levels (ρ = 0.528, P = 0.029) was seen. CONCLUSION: A state-of-the-art imaging modality was used in c-TA patients and revealed a strong arterial FDG uptake even in patients in apparent remission. We suppose that this finding may represent silent activity in the vessel wall; however, we cannot exclude the possibility of arterial remodelling. Importantly, a negative imaging scan may help in immunosuppression withdrawal in daily clinical practice.