Staging liver fibrosis after severe yellow fever with ultrasound elastography in Brazil: A six-month follow-up study

BACKGROUND: Yellow fever (YF) is a hemorrhagic disease caused by an arbovirus endemic in South America, with recent outbreaks in the last years. Severe cases exhibit fulminant hepatitis, but there are no studies regarding its late-term effects on liver parenchyma. Thus, the aim of this study was to determine the frequency and grade of liver fibrosis in patients who recovered from severe YF and to point out potential predictors of this outcome. METHODOLOGY/PRINCIPAL FINDINGS: We followed-up 18 patients who survived severe YF during a recent outbreak (January-April 2018) in Brazil using ultrasound (US) with shear-wave elastography (SWE) at 6 months after symptoms onset. No patient had previous history of liver disease. Median liver stiffness (LS) was 5.3 (4.6–6.4) kPa. 2 (11.1%) patients were classified as Metavir F2, 1 (8.3%) as F3 and 1 (8.3%) as F4; these two last patients had features of cardiogenic liver congestion on Doppler analysis. Age and cardiac failure were associated with increased LS (p = 0.036 and p = 0.024, respectively). SAPS-3 at ICU admission showed a tendency of association with significant fibrosis (≥ F2; p = 0.053). 7 patients used sofosbuvir in a research protocol, of which none showed liver fibrosis (p = 0.119). CONCLUSIONS/SIGNIFICANCE: We found a low frequency of liver fibrosis in severe YF survivors. US with SWE may have a role in the follow up of patients of age and / or with comorbidities after hospital discharge in severe YF, a rare but reemergent disease.