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Volume 32, Number 4—April 2026
Dispatch
Guillain-Barré Syndrome and Visual Impairment Associated with Emerging Oropouche Virus Lineage, Brazil, 2024
, Fernanda Martins Maia Carvalho, Antonio Silva Lima Neto, Ana Maria Cabral Maia, Matheus Andrighetti Rossi, Milena Sales Pitombeira, Paula Camila Alves de Assis Pereira Matos, Tania Mara Silva Coelho, Lauro Vieira Perdigão Neto, Lívia Mendes de Almeida, Felipe Gomes Naveca, Carla Santos de Oliveira, Fernanda de Bruycker-Nogueira, Ana Maria Bispo de Filippis, Kleber Giovanni Luz, André Ricardo Ribas Freitas, and Luciano Pamplona de Góes Cavalcanti
Table
Results of laboratory screening in study of Guillain-Barré syndrome and visual impairment associated with emerging Oropouche virus lineage, Brazil, 2024*
| Laboratory test | Result | Reference range or detection method |
|---|---|---|
| Hematology and biochemistry | ||
| Hemoglobin | 15.3 g/dL | 11.5–15.0 g/dL |
| Leukocytes | 8,500/µL | 3,600–11,000 cells/µL |
| Platelets | 346,000/µL | 150,000–450,000/µL |
| C-reactive protein | 5 mg/L | <5 mg/L |
| Erythrocyte sedimentation rate | 27 mm/h | 0–20 mm/h |
| Calcium | 10.7 mg/dL | 8.50–10.50 mg/dL |
| Creatinine | 0.72 mg/dL | 0.60–1.10 mg/dL |
| Alanine aminotransferase | 63 U/L | <31 U/L |
| Aspartate aminotransferase | 22 U/L | <32 U/L |
| C3 | 118 mg/dL | 90–180 mg/dL |
| C4 | 43.8 mg/dL | 10–40 mg/dL |
| Rheumatoid factor |
20.7 IU/mL |
0–15 IU/mL |
| Cerebrospinal fluid analysis | ||
| Cell count | 2 cells/µL | 0–4 cells/µL |
| Protein | 156 mg/dL | 15–40 mg/dL |
| Glucose | 135 mg/dL | 40–70 mg/dL |
| Adenosine deaminase |
0.72 U/L |
0–9 U/L |
| Infectious disease markers | ||
| HIV | Nonreactive | Chemiluminescent immunoassay |
| Hepatitis B surface antigen | Nonreactive | Chemiluminescent immunoassay |
| Hepatitis C | Nonreactive | Chemiluminescent immunoassay |
| Ssyphilis/neurosyphilis | Nonreactive | Flocculation (VDRL) |
| Mycobacterium tuberculosis DNA | Nonreactive | Xpert MTB/RIF (Cepheid, https://www.cepheid.com) |
| Zika virus† | Nonreactive | qRT-PCR, ELISA IgM (serum and CSF) |
| Chikungunya virus† | Nonreactive | qRT-PCR, ELISA IgM (serum and CSF) |
| Dengue virus† | Nonreactive | qRT-PCR, ELISA IgM (serum and CSF |
| Oropouche virus† |
Positive |
qRT-PCR (serum) |
| Autoimmune profile | ||
| Antinuclear antibodies‡ | Negative | Indirect immunofluorescence assay on Hep-2 cells |
| Aquaporin-4 antibodies‡ | Negative | Cell-based assay |
| MOG antibodies‡ | Negative | Cell-based assay |
*MOG, myelin oligodendrocyte glycoprotein; qRT-PCR, quantitative reverse transcription PCR; VDRL, Venereal Disease Research Laboratory. †Oropouche virus qRT-PCR and qRT-PCR for dengue, Zika, chikungunya, and Mayaro viruses, as well as serologic testing, were performed using serum collected on August 14, 2024. ‡Autoimmune screening tests, including antinuclear antibody (ANA), and aquaporin 4 and MOG antibodies, were collected during the home visit on February 5, 2025. All other tests were conducted during hospitalization, September 17–October 1, 2024.