Evolução clínica de pacientes com febre amarela: avaliação de fatores de risco relacionados a mortalidade e indicação de tratamentos alternativos

Abstract

Yellow fever (YF) is a disease caused by an RNA virus belonging to the Flaviviridae family. In Brazil, the virus is naturally present in the environment, in a cycle that involves mosquitoes of the genera Haemagogus and Sabethes infecting different primates including humans. (MINAS GERAIS, 2017a). The epicenter of the largest epidemic ever recorded in the country was between 2016 and 2019, in the South East region, particularly the states of Minas Gerais and São Paulo, when 3,242 cases of YF were reported in Minas Gerais (TABNET, 2022). There is still a lack of knowledge about the risk factors that can lead to death, despite the existence of a few publications on the matter. Elevation of transaminases is classically associated with higher mortality, however, recent studies indicate that age, bilirubin, creatinine and INR may be markers of severity (TUBOI et al., 2007; ÁVILA et al., 2020; RIBEIRO et al., 2019). The aim of this study is to characterize the clinical-epidemiological profile of patients with YF admitted to the referral hospital during de YF outbreak in 2017 and 2018. In addition, it also aims to determine the risk factors associated with fulminant hepatitis and mortality in these patients. This study analyzed the clinical profiles and laboratory data of 229 patients who were diagnosed with yellow fever, admitted to a reference hospital. Of this total, 197 (86%) were male, and their ages were about 46. The median time between the onset of symptoms and hospitalization was four days, and the median hospital stay length was six days. Overall mortality was 20.5% (n=47). Despite a significant increase in liver enzymes, with ALT and AST levels of 1,167 and 1,138 IU/L, respectively, parameters such as total bilirubin showed a slight increase (1.2 mg/dL). In the multivariate analysis, changes in lactate dehydrogenase (LDH) and lactate values in the first 24 hours of hospitalization, and leukocytes and AST evaluated after 36 to 48 hours are associated with a higher death risk. These laboratory markers were used in a mathematical model, and it was possible to calculate the percentage probability of the death of a patient, during the manifestation of the disease. Thus, it is concluded that these markers can be helpful in the selection of patients for allocation to the Intensive Care Unit (ICU) and other interventions such as plasmapheresis. Finally, establishing severity criteria could be useful in selecting patients undergoing fulminant hepatitis who may benefit from liver transplantation as a lifesaving measure.