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

Int J Infect Dis. 2024 Aug:145:107090. doi: 10.1016/j.ijid.2024.107090. Epub 2024 May 16.

Abstract

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.

Keywords: Arbovirus; Brazil; Chikungunya; Encephalitis.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Viral / blood
  • Brazil / epidemiology
  • Chikungunya Fever* / blood
  • Chikungunya Fever* / diagnosis
  • Chikungunya Fever* / epidemiology
  • Chikungunya Fever* / virology
  • Chikungunya virus* / genetics
  • Chikungunya virus* / isolation & purification
  • Child
  • Child, Preschool
  • Dengue Virus / genetics
  • Dengue Virus / isolation & purification
  • Encephalitis, Viral / diagnosis
  • Encephalitis, Viral / epidemiology
  • Encephalitis, Viral / virology
  • Enterovirus / genetics
  • Enterovirus / isolation & purification
  • Female
  • Herpesvirus 3, Human / genetics
  • Herpesvirus 3, Human / isolation & purification
  • Humans
  • Immunoglobulin M / blood
  • Infant
  • Male
  • Middle Aged
  • Phylogeny
  • Whole Genome Sequencing
  • Young Adult

Substances

  • Antibodies, Viral
  • Immunoglobulin M