Table 1. Diagnostic certainty, clinical, epidemiologic, and immunologic investigations for 42 patients with suspected yellow fever vaccine–associated neurologic disease, according to Brighton Collaboration classification criteria, São Paulo, Brazil, 2017–2018*.

Characteristic	Aseptic meningitis, n = 24	Encephalitis, n = 8	Guillain-Barré syndrome, n = 3‡	Myelitis, n = 2‡	ADEM, n = 2‡	Unclassified† n = 3‡
Age, y, median (IQR) [range]	36 (23.75–46.75)	40 (30.25–58.25)	59 (43–73)	33 [25–41]	37 [22–52]	28 [25–50]
Sex, no (%)
F	7 (29)	5 (62)	1 (33)	2 (100)	1 (50)	0
M	17 (71)	3 (38)	2 (67)	0	1 (50)	3 (100)
Vaccine–symptom interval, d, median (IQR) [range]	17 (7.75–20.00)	7 (3.50–17.25)	16 [14–31]	11.5 [0–23]	10 [5–15]	13 [3–29]
No. full/fractional/unknown doses	18/4/2	5/3/0	3/0/0	1/1/0	1/1/0	2/0/1
YF virus IgM in CSF, reactive/total tested	10/17	4/7	0/2	0/1	1/2	0/1
YF virus in CSF detected by PCR, detected/total tested	0/17	0/6	0/2	0/1	0/1	0/1
BC level of diagnostic certainty, no. cases
Level 1	17	0	1	0	2	NA
Level 2	7	8	2	2	0	NA
Brazil MoH/CDC classification, no. cases	Level 1 NRL: 21; level 2 NRT: 1; definite NRT: 1; suspected NRT: 1	Level 1 NRL: 2; level 2 NRT: 3; definite NRT: 2; suspected NRT: 1	Level 2 PNS: 1; probable PNS:2	Level 1 NRL: 2	Probable CNS: 2	Level 1 NRL: 3

*ADEM, acute disseminated encephalomyelitis; BC, Brighton Collaboration; CDC, Centers for Disease Control and Prevention); CNS, autoimmune neurologic disease with central nervous system involvement; CSF, cerebrospinal fluid; IQR, interquartile range; NA, not applicable; NRL, neurologic disease; NRT, neurotropic disease; MoH, Ministry of Health; PNS, autoimmune neurologic disease with peripheral nervous system involvement; YF, yellow fever.
†Includes 1 case of ataxia, 1 of opsoclonus-myoclonus-ataxia, 1 case of optic neuritis.
‡In groups with <5 cases, range is substituted for IQR.