Characterization and Investigation of Risk Factors for Late-Relapsing Hepatitis After Yellow Fever.

BACKGROUND: Late-relapsing hepatitis after yellow fever (LHep-YF) during the convalescent phase of the disease has been described during recent yellow fever (YF) outbreaks in Brazil. LHep-YF is marked by a rebound in liver enzymes and nonspecific clinical manifestations around 46-60 days after YF symptom onset. METHODS: Here we have characterized the clinical course and risk factors for LHep-YF using data from a representative cohort of patients who survived YF in Brazil, 2017-2018. A total of 221 YF-positive patients were discharged from the infectious disease reference hospital in Minas Gerais and were followed up at 30, 45, and 60 days post-symptom onset. RESULTS: From 46 to 60 days post-symptom onset, 16% of YF patients (n = 36/221) exhibited a rebound of aminotransferases (aspartate aminotransferase or alanine aminotransferase >500 IU/L), alkaline phosphatase, and total bilirubin levels. Other etiologies of liver inflammation such as infectious hepatitis, autoimmune hepatitis, and metabolic liver disease were ruled out. Jaundice, fatigue, headache, and low platelet levels were associated with LHep-YF. Demographic factors, clinical manifestations, laboratory tests, ultrasound findings, and viral load during the acute phase of YF were not associated with the occurrence of LHep-YF. CONCLUSIONS: These findings provide new data on the clinical course of Late-relapsing hepatitis during the convalescent phase of YF and highlight the need for extended patient follow-up after acute YF.

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.

Consumptive coagulopathy of severe yellow fever occurs independently of hepatocellular tropism and massive hepatic injury.

Yellow fever (YF) is a mosquito-transmitted viral disease that causes tens of thousands of deaths each year despite the long-standing deployment of an effective vaccine. In its most severe form, YF manifests as a hemorrhagic fever that causes severe damage to visceral organs. Although coagulopathy is a defining feature of severe YF in humans, the mechanism by which it develops remains uncertain. Hepatocytes are a major target of yellow fever virus (YFV) infection, and the coagulopathy in severe YF has long been attributed to massive hepatocyte infection and destruction that results in a defect in clotting factor synthesis. However, when we analyzed blood from Brazilian patients with severe YF, we found high concentrations of plasma D-dimer, a fibrin split product, suggestive of a concurrent consumptive process. To define the relationship between coagulopathy and hepatocellular tropism, we compared infection and disease in Fah-/-, Rag2-/-, and Il2rɣ-/- mice engrafted with human hepatocytes (hFRG mice) and rhesus macaques using a highly pathogenic African YFV strain. YFV infection of macaques and hFRG mice caused substantial hepatocyte infection, liver damage, and coagulopathy as defined by virological, clinical, and pathological criteria. However, only macaques developed a consumptive coagulopathy whereas YFV-infected hFRG mice did not. Thus, infection of cell types other than hepatocytes likely contributes to the consumptive coagulopathy associated with severe YF in primates and humans. These findings expand our understanding of viral hemorrhagic disease and associated coagulopathy and suggest directions for clinical management of severe YF cases.

Thromboelastometry identifies coagulopathy associated with liver failure and disseminated intravascular coagulation caused by yellow fever, guiding specific hemostatic therapy: a case report. / A tromboelastometria identifica coagulopatia associada à insuficiência hepática e coagulação intravascular disseminada causadas por febre amarela, orientando a terapia hemostática específica: um relato de caso.

This case report a severe case of yellow fever complicated by liver failure and disseminated intravascular coagulation. Thromboelastometry was capable of identifying clotting disorders and guiding hemostatic therapy. We report the case of a 23-year-old male admitted to the Intensive Care Unit with sudden onset of fever, generalized muscle pain associated with liver failure, and disseminated intravascular coagulation. The results of conventional laboratory tests showed thrombocytopenia, whereas thromboelastometry suggested coagulopathy with slight hypofibrinogenemia, clotting factor consumption, and, consequently, an increased risk of bleeding. Unlike conventional laboratory tests, thromboelastometry identified the specific coagulation disorder and thereby guided hemostatic therapy. Both fibrinogen concentrates and vitamin K were administered, and no blood component transfusion was required, even in the presence of thrombocytopenia. Administration of hemostatic drugs, including fibrinogen concentrate and vitamin K, improved thromboelastometric parameters, correcting the complex coagulation disorder. Blood component transfusion was not performed, and there was no bleeding.

Este relato de caso detalha um caso grave de febre amarela complicada por insuficiência hepática e coagulação intravascular disseminada. A tromboelastometria foi capaz de identificar os distúrbios da coagulação e orientar o tratamento hemostático. Relatamos o caso de um homem com 23 anos de idade admitido na unidade de terapia intensiva com quadro com início abrupto de febre e dor muscular generalizada associados a insuficiência hepática e coagulação intravascular disseminada. Os resultados dos exames laboratoriais convencionais revelaram trombocitopenia, enquanto a tromboelastometria sugeriu coagulopatia com discreta hipofibrinogenemia, consumo de fatores de coagulação e, consequentemente, aumento do risco de sangramento. Diferentemente dos exames laboratoriais convencionais, a tromboelastometria identificou o distúrbio de coagulação específico e, assim, orientou o tratamento hemostático. Administraram-se concentrados de fibrinogênio e vitamina K, não sendo necessária a transfusão de qualquer componente do sangue, mesmo na presença de trombocitopenia. A tromboelastometria permitiu a identificação precoce da coagulopatia e ajudou a orientar a terapêutica hemostática. A administração de fármacos hemostáticos, incluindo concentrados de fibrinogênio e vitamina K, melhorou os parâmetros tromboelastométricos, com correção do transtorno da coagulação. Não se realizou transfusão de hemocomponentes, e não ocorreu qualquer sangramento.

A tromboelastometria identifica coagulopatia associada à insuficiência hepática e coagulação intravascular disseminada causadas por febre amarela, orientando a terapia hemostática específica: um relato de caso / Thromboelastometry identifies coagulopathy associated with liver failure and disseminated intravascular coagulation caused by yellow fever, guiding specific hemostatic therapy: a case report

RESUMO Este relato de caso detalha um caso grave de febre amarela complicada por insuficiência hepática e coagulação intravascular disseminada. A tromboelastometria foi capaz de identificar os distúrbios da coagulação e orientar o tratamento hemostático. Relatamos o caso de um homem com 23 anos de idade admitido na unidade de terapia intensiva com quadro com início abrupto de febre e dor muscular generalizada associados a insuficiência hepática e coagulação intravascular disseminada. Os resultados dos exames laboratoriais convencionais revelaram trombocitopenia, enquanto a tromboelastometria sugeriu coagulopatia com discreta hipofibrinogenemia, consumo de fatores de coagulação e, consequentemente, aumento do risco de sangramento. Diferentemente dos exames laboratoriais convencionais, a tromboelastometria identificou o distúrbio de coagulação específico e, assim, orientou o tratamento hemostático. Administraram-se concentrados de fibrinogênio e vitamina K, não sendo necessária a transfusão de qualquer componente do sangue, mesmo na presença de trombocitopenia. A tromboelastometria permitiu a identificação precoce da coagulopatia e ajudou a orientar a terapêutica hemostática. A administração de fármacos hemostáticos, incluindo concentrados de fibrinogênio e vitamina K, melhorou os parâmetros tromboelastométricos, com correção do transtorno da coagulação. Não se realizou transfusão de hemocomponentes, e não ocorreu qualquer sangramento.

Abstract This case report a severe case of yellow fever complicated by liver failure and disseminated intravascular coagulation. Thromboelastometry was capable of identifying clotting disorders and guiding hemostatic therapy. We report the case of a 23-year-old male admitted to the Intensive Care Unit with sudden onset of fever, generalized muscle pain associated with liver failure, and disseminated intravascular coagulation. The results of conventional laboratory tests showed thrombocytopenia, whereas thromboelastometry suggested coagulopathy with slight hypofibrinogenemia, clotting factor consumption, and, consequently, an increased risk of bleeding. Unlike conventional laboratory tests, thromboelastometry identified the specific coagulation disorder and thereby guided hemostatic therapy. Both fibrinogen concentrates and vitamin K were administered, and no blood component transfusion was required, even in the presence of thrombocytopenia. Administration of hemostatic drugs, including fibrinogen concentrate and vitamin K, improved thromboelastometric parameters, correcting the complex coagulation disorder. Blood component transfusion was not performed, and there was no bleeding.

Hepatitis Relapse after Yellow Fever Infection: Is There Another Wave?

During the yellow fever (YF) outbreak in Brazil, many cases of fulminant hepatitis were seen, although mild to moderate hepatitis was mostly observed with complete recovery. This report presents a case of late-onset hepatitis due to YF relapse. The patient sought medical attention after jaundice recurrence 40 days after the first YF hepatitis episode. This case highlights the importance of patient follow-up after the complete resolution of YF symptoms and discharge.

Late-Relapsing Hepatitis after Yellow Fever.

One patient presented hyporexia, asthenia, adynamia, and jaundice two months after acute yellow fever (YF) onset; plus laboratory tests indicating hepatic cytolysis and a rebound of alanine and aspartate transaminases, and total and direct bilirubin levels. Laboratory tests discarded autoimmune hepatitis, inflammatory or metabolic liver disease, and new infections caused by hepatotropic agents. Anti-YFV IgM, IgG and neutralizing antibodies were detected in different times, but no viremia. A liver biopsy was collected three months after YF onset and tested positive for YFV antigens and wild-type YFV-RNA (364 RNA-copies/gram/liver). Transaminases and bilirubin levels remained elevated for five months, and the arresting of symptoms persisted for six months after the acute YF onset. Several serum chemokines, cytokines, and growth factors were measured. A similar immune response profile was observed in the earlier phases of the disease, followed by more pronounced changes in the later stages, when transaminases levels returned to normal. The results indicated viral persistence in the liver and continual liver cell damage three months after YF onset and reinforced the need for extended follow-ups of YF patients. Further studies to investigate the role of possible viral persistence and the immune response causing relapsing hepatitis following YF are also necessary.

Burden and etiopathogenesis of acute kidney injury in the tropics.

Acute kidney injury (AKI) is prevalent and is associated with high morbidity and mortality globally. The epidemiology differs remarkably between developing and developed economies. Infections, diarrheal illnesses, obstetric causes and nephrotoxins are very rampant in the tropics. Even though the etiologies are different, the final common pathway in the pathogenesis is similar - tubular damage or necrosis, tubular blockage, and back leak of glomerular filtrate. The mechanism of AKI in infections could be through ischemic insult consequent to hypovolemia and/or hemoglobinuria, as seen in malaria and viral hemorrhagic fevers, interstitial inflammation, or nephrotoxicity. On the contrary, the mechanism of nephrotoxin-induced AKI includes direct toxic effect on the renal tubules, intratubular precipitation of substances like djenkolic and oxalic acids (crystalluria) as well as intratubular obstruction and AKI. Toxicity could also be indirect by interacting with the pharmacokinetic profile of other coadministered medications. Bites and envenomation as well as obstetric complications also induce AKI through hypovolemia, interstitial nephritis, and other unclear mechanisms in eclampsia and preeclampsia. Outcome is variable and dependent on etiology. Prognosis appears to be significantly better in hypovolemic or prerenal and/or obstructive AKI compared to intrarenal or intrinsic AKI.

Hepatitis Relapse after Yellow Fever Infection: Is There Another Wave?

Abstract During the yellow fever (YF) outbreak in Brazil, many cases of fulminant hepatitis were seen, although mild to moderate hepatitis was mostly observed with complete recovery. This report presents a case of late-onset hepatitis due to YF relapse. The patient sought medical attention after jaundice recurrence 40 days after the first YF hepatitis episode. This case highlights the importance of patient follow-up after the complete resolution of YF symptoms and discharge.

Canine visceral leishmaniasis in area with recent Leishmania transmission: prevalence, diagnosis, and molecular identification of the infecting species

Abstract INTRODUCTION: Canine visceral leishmaniasis (CVL) is an endemic disease in Brazil, and integrated control actions have been adopted by the Brazilian Ministry of Health to control its spread. However, the transmission profile is unknown in areas with recent CVL cases, including Itaúna, located in the Brazilian state of Minas Gerais, where the present study was carried out. METHODS: A total of 2,302 dogs from 12 neighborhoods were serologically tested for canine VL using the current diagnostic protocol adopted by the Brazilian Ministry of Health. Test positivity rate (TPR) and CVL prevalence were determined for each neighborhood. The presence of Leishmania was assessed in 60 seropositive dogs which had been recommended for euthanasia. Twenty-two of them (37%) were asymptomatic, and 38 (63%) were symptomatic for CVL. Parasitological (myeloculture and smear/imprint) and molecular (PCR) methods were employed for Leishmania detection in bone marrow, spleen, mesenteric lymph nodes, and ear skin. The infecting Leishmania species was identified by DNA sequencing. RESULTS: CVL prevalence (per 1,000 dogs) varied from 0.0-166.67, depending on the neighborhood, with a mean of 68.96 (SD 51.38). Leishmania DNA was detected in at least one tissue from all seropositive dogs, with comparable TPR among tissues. Leishmania parasites were identified in most (54/60) seropositive dogs, and the infecting parasite was identified as Leishmania infantum in all of these. CONCLUSIONS: Prevalence of CVL is a contributor to the spread of visceral leishmaniasis in Itaúna.

Sofosbuvir inhibits yellow fever virus in vitro and in patients with acute liver failure.

INTRODUCTION AND OBJECTIVES: Direct antiviral agents (DAAs) are very efficient in inhibiting hepatitis C virus and might be used to treat infections caused by other flaviviruses whose worldwide detection has recently increased. The aim of this study was to verify the efficacy of DAAs in inhibiting yellow fever virus (YFV) by using drug repositioning (a methodology applied in the pharmaceutical industry to identify new uses for approved drugs). MATERIALS AND METHODS: Three DAAs were evaluated: daclatasvir, sofosbuvir and ledipasvir or their combinations. For in vitro assays, the drugs were diluted in 100% dimethyl sulfoxide. Vaccine strain 17D and a 17D strain expressing the reporter fluorescent protein were used in the assays. A fast and reliable cell-based screening assay using Vero cells or Huh-7 cells (a hepatocyte-derived carcinoma ell line) was carried out. Two patients who acquired yellow fever virus with acute liver failure were treated with sofosbuvir for one week as a compassionate use. RESULTS: Using a high-content screening assay, we verified that sofosbuvir presented the best antiviral activity against YFV. Moreover, after an off-label treatment with sofosbuvir, the two female patients diagnosed with yellow fever infection displayed a reduction in blood viremia and an improvement in the course of the disease, which was observed in the laboratory medical parameters related to disease evolution. CONCLUSIONS: Sofosbuvir may be used as an option for treatment against YFV until other drugs are identified and approved for human use. These results offer insights into the role of nonstructural protein 5 (NS5) in YFV inhibition and suggest that nonstructural proteins may be explored as drug targets for YFV treatment.

Yellow fever in Brazil threatens successful recovery of endangered golden lion tamarins.

The golden lion tamarin is an endangered primate endemic to Brazil's Atlantic Forest. Centuries of deforestation reduced numbers to a few hundred individuals in isolated forest fragments 80 km from Rio de Janeiro city. Intensive conservation action including reintroduction of zoo-born tamarins into forest fragments 1984-2000, increased numbers to about 3,700 in 2014. Beginning in November 2016, southeastern Brazil experienced the most severe yellow fever epidemic/epizootic in the country in 80 years. In May 2018, we documented the first death of a golden lion tamarin due to yellow fever. We re-evaluated population sizes and compared them to results of a census completed in 2014. Tamarin numbers declined 32%, with ca. 2,516 individuals remaining in situ. Tamarin losses were significantly greater in forest fragments that were larger, had less forest edge and had better forest connectivity, factors that may favor the mosquito vectors of yellow fever. The future of golden lion tamarins depends on the extent of additional mortality, whether some tamarins survive the disease and acquire immunity, and the potential development of a vaccine to protect the species against yellow fever.

Kidney involvement in yellow fever: a review.

Yellow fever is one of the most important mosquito-borne diseases, which still affects a significant number of people every year, mainly in tropical countries. Mortality can be high, even with intensive treatment due to multiple organ failure, including acute kidney injury (AKI). This disease can also be a burden on the health care system in developing countries, without mentioning the number of lives that could be spared with an early diagnosis and adequate monitoring and treatment. The pathophysiology of yellow fever-induced acute kidney injury (AKI) is still to be completely understood, and the best clinical approach has not yet been determined. This manuscript presents the most recent scientific evidence of kidney involvement in yellow fever, since AKI plays an important role in the mortality rate. Recent outbreaks have occurred in Brazil and further studies are required to provide a better clinical control for patients with yellow fever.

Severe Yellow Fever and Extreme Hyperferritinemia Managed with Therapeutic Plasma Exchange.

A 43-year-old man was admitted to the intensive care unit and diagnosed with yellow fever. He presented with refractory bleeding, extreme hyperferritinemia, and multiple organ dysfunction syndrome, requiring renal replacement therapy, mechanical ventilation, and treatment with vasoactive drugs. Because the bleeding did not respond to fresh-frozen plasma administration, the patient received therapeutic plasma exchange, which was accompanied by a marked improvement of the clinical and biochemical parameters, including a significant decline in serum ferritin levels.

Liver Transplantation for Acute Liver Failure due to Yellow Fever: A Case Report.

Yellow fever is a noncontagious disease caused by an arbovirus in the Flaviviridae family. It is an endemic disease in the tropical forests of Africa and South America, with the mosquito as a vector. Approximately half of those infected will be asymptomatic, while 15% will develop the severe/malignant form of the disease that includes renal and hepatic failure, bleeding, and neurological impairment as the principal symptoms. The lethality of the severe form reaches up to 70%. The objective of this study was to report on the case of a patient who was transferred to the hepatobiliary unit of our service due to acute liver failure due to yellow fever. He was treated with liver transplantation. The patient progressed satisfactorily, being discharged from the intensive care unit in 10 days and discharged from the hospital within 19 days after transplantation. Despite the encouraging result of our team, this has not been applied to other centers that have also performed this modality of treatment; therefore, the question remains as to whether and when to recommend liver transplantation for treatment of severe yellow fever.