Every new research finding gives us something else to detest about Zika, and this report by CIDRAP's Lisa Schnirring is no exception: Brazilian study sheds new light on Zika neuro complications in adults. Excerpt:
In adults, Zika virus infection can cause a diverse array of serious neurologic complications, according to a case series of patients during Brazil's outbreak who were treated at a neurology referral hospital in Rio de Janeiro.
In other developments, another research group from Brazil reported a reduction in the birth rate in one of the country's biggest cities and the US Food and Drug Administration (FDA) recently issued an emergency use authorization (EUA) for the first test that can simultaneously assess for Zika, all dengue serotypes, chikungunya, and West Nile virus.
Patient series finds diverse problems, unusual features
In the neurologic complication study, researchers reported on 40 adults who were hospitalized with acute-onset neurologic symptoms who were evaluated for Zika infection Dec 5, 2015, and May 10, 2016. The team published its findings today in JAMA Neurology.
Of the 40 patients, 35 had evidence of recent Zika infection in blood or cerebrospinal fluid (CSF). Of those who were positive for Zika virus, 27 had Guillain-Barre syndrome (GBS), 5 had encephalitis, 2 had transverse myelitis, and 1 had chronic inflammatory demyelinating polyneuropathy.
Among the 27 with GBS, 13 had cranial nerve involvement and three had facial numbness or trouble swallowing. Of the patients with encephalitis, two had accompanying neuromuscular findings, seen with other flavivirus neurologic complications.
Serum and CSF were tested for Zika virus using real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) and IgM antibody assays. Researchers also recorded clinical data, radiographic and electrophysiological test findings, and 3-month function outcomes.
Nine of the patients required intensive care unit treatment and five required mechanical ventilation.
The authors found Zika IgM in the CSF of many of the patients, often at significantly higher levels than in blood, which they said is a sign of direct Zika virus penetration. Two patients tested positive for dengue on serum but not CSF samples.
When they compared the number of complications with baseline[MS1] levels in Brazil, they found that the incidences of GBS and encephalitis rose 6-fold and 3.5-fold compared with the period before the outbreak.
They concluded that Zika infection is linked to a diverse array of serious neurologic disorders and that serologic and molecular tests on blood and CSF can be useful as a less expensive and more accessible alternative to plaque reduction neutralization testing in developing countries.
