Detection of encephalitis-causing viruses reveals predominance of chikungunya virus in the state of Bahia, Brazil.

OBJECTIVES: Encephalitis is a severe neurological syndrome for which herpesvirus and enteroviruses are the most common etiological agents. Arboviruses, a wildly diverse group of pathogens, are also critical epidemiological agents associated with encephalitis. In Brazil, little is known about the causative agents of encephalitis. METHODS: We conducted a hospital surveillance for encephalitis between 2020 and 2022. Molecular (RT-PCR and qPCR) and serological (virus-specific IgM and viral antigens) techniques were performed in cerebrospinal fluid and serum samples obtained from study participants. RESULTS: In the 43 participants evaluated, the etiologic agent or the presence of IgM was detected in 16 (37.2%). Nine (20.9%) cases were positive for chikungunya virus (CHIKV), three (7.0%) for dengue virus, two (4.7%) for human adenovirus, one (2.3%) for varicella-zoster virus, and one (2.3%) for enterovirus. Whole-genome sequencing revealed that the CHIKV identified belongs to the East/Central/South African lineage. CONCLUSION: Herein, CHIKV is a common pathogen identified in encephalitis cases. Our results reinforce previous evidence that chikungunya represents a significant cause of encephalitis during CHIKV outbreaks and epidemics and add to existing information on the epidemiology of encephalitis in Brazil.

Guillain-Barré Syndrome and Miller Fisher Syndrome in Association With an Arboviral Outbreak: A Brazilian Case Series.

Introduction: Guillain-Barré syndrome (GBS) in association with arboviruses, such as Zika, chikungunya, and dengue, has been previously documented; however, Miller-Fisher Syndrome (MFS) and other GBS subtypes are rarely reported. Methods: We identified a series of GBS and MFS cases that were followed during the Zika virus outbreak in Salvador, Brazil (2015-2016). Blood and CSF samples were collected for virus diagnosis. In addition, serological studies to verify previous arboviral infection and electromyography (EMG) were performed. Results: Of the 14 patients enrolled, 10 were diagnosed with GBS, including three GBS subtypes (two cases of bifacial weakness with paresthesia and one case of paraparetic GBS), and four as MFS. IgM antibodies against one or more of three arboviruses were present in 11 (78.6%) patients: anti-zika IgM positivity in eight (57%), anti-Chikungunya IgM in three (21%), and anti-Dengue in one (7%) individual. A single case was positive for both anti-Dengue IgM and anti-Chikungunya IgM, suggesting co-infection. EMG revealed an AIDP pattern in all nine patients analyzed. Conclusion: The current case series contributes to our knowledge on the clinical presentation of arbovirus-associated GBS and its subtypes, including MFS, and serves as an alert to clinicians and other healthcare professionals in regions affected by arbovirus outbreaks. We highlight the importance of recognizing arboviruses in diagnosing GBS and its subtypes.

Biliary ascariasis and severe bacterial outcomes: Report of three cases from a paediatric hospital in Brazil.

INTRODUCTION: Biliary ascariasis, although uncommon, can lead to infectious complications and severe outcomes. This study reported three patients with biliary ascariasis and who were admitted to a paediatric hospital in Salvador, Brazil. CASE REPORTS: Case 1: A 1-year-old boy, with HIV, hospitalised with diarrhoea, fever, pain, and abdominal distension. He underwent an exploratory laparotomy, which showed peritonitis secondary to a perforation of the hepatic duct by ascaris. Case 2: A 3-year-old boy admitted with fever, abdominal pain and jaundice. Imaging examination was suggestive of ascaris in the intrahepatic biliary tract and a hepatic abscess. Case 3: A 7-year-old boy who was hospitalised with a history of abdominal colic, jaundice and fever, with a suggestive image of ascaris in the biliary tract and evolution to sepsis. DISCUSSION: Three cases of biliary ascariasis were reported with severe infectious complications involving peritonitis, hepatic abscess and sepsis. CONCLUSION: In endemic regions, biliary ascariasis should be considered in cases with jaundice, abdominal pain and fever, due to its morbidity and risk of complications.

Anti-ganglioside antibodies in patients with Zika virus infection-associated Guillain-Barré Syndrome in Brazil.

Zika virus infection is associated with the development of Guillain-Barré syndrome (GBS), a neurological autoimmune disorder caused by immune recognition of gangliosides and other components at nerve membranes. Using a high-throughput ELISA, we have analyzed the anti-glycolipid antibody profile, including gangliosides, of plasma samples from patients with Zika infections associated or not with GBS in Salvador, Brazil. We have observed that Zika patients that develop GBS present higher levels of anti-ganglioside antibodies when compared to Zika patients without GBS. We also observed that a broad repertoire of gangliosides was targeted by both IgM and IgG anti-self antibodies in these patients. Since Zika virus infects neurons, which contain membrane gangliosides, antigen presentation of these infected cells may trigger the observed autoimmune anti-ganglioside antibodies suggesting direct infection-induced autoantibodies as a cause leading to GBS development. Collectively, our results establish a link between anti-ganglioside antibodies and Zika-associated GBS in patients.

Opsoclonus-myoclonus-ataxia syndrome associated with chikungunya and dengue virus co-infection.

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare neurological disorder characterized by irregular multidirectional eye movements, myoclonus, cerebellar ataxia, sleep disturbances, and cognitive dysfunction. Although most commonly related to paraneoplastic syndrome, this condition has occasionally been described following infectious illnesses. This article reports the first case of OMAS in association with chikungunya and dengue virus co-infection. The genetic analysis identified chikungunya virus of East/Central/South African genotype and dengue serotype 4 virus of genotype II. This report represents an unusual clinical syndrome associated with viral co-infection and reinforces the need for clinical vigilance with regard to neurological syndromes in the context of emergent arboviruses.

Guillain-Barré Syndrome After Zika Virus Infection in Brazil.

Zika virus (ZIKV) is an emerging flavivirus, which has caused a widespread outbreak in the Americas. Shortly after its introduction in 2015, a cluster of cases with Guillain-Barré syndrome was detected in Brazil. Herein, we describe two cases from the city of Salvador, who developed ascending paresis after an acute exanthematous illness. The patients were admitted to the intensive care unit with tetraparesis and cranial nerve palsy, which resolved after intravenous administration of human immunoglobulin. Serological evaluation detected IgM-specific ZIKV antibodies. In regions of Zika virus transmission, health-care workers must be aware of the potential severe neurological complications associated with ZIKV infection and be prepared to provide prompt diagnosis, treatment, and supportive care.

Zika virus complete genome from Salvador, Bahia, Brazil.

In May 2015 the first autochthonous Zika virus infection was reported in Brazil. Rapid and urgent measures are needed to contain the ongoing outbreak. Here we report the full-length ZIKV coding sequence from Bahia. Genetic analysis of outbreak sequences will be essential for characterizing the diversity of circulating strains, identifying hotspots of virus transmission and guiding public health control. Rapid and urgent measures are needed to contain the ongoing outbreak.