New Insight Into Zika Infection's Link to Neurological Damage

Virus found in central nervous system weeks after clearance from blood

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BOSTON – A new study led by researchers at Beth Israel Deaconess Medical Center (BIDMC) has found that Zika virus can persist in cerebrospinal fluid (CSF), lymph nodes and colorectal tissues of infected rhesus monkeys weeks after the virus has been cleared from blood, urine and mucosal secretions. The findings, which suggest a mechanism for the neurological damage associated with Zika infection, were published in the journal Cell .

“These data give us important new insights into how Zika virus causes disease and how it damages the central nervous system and other tissues,” says Dan Barouch, MD, PhD, Director of the Center for Virology and Vaccine Research at BIDMC. “The data also raise the possibility that neurologic and lymphoid diseases may occur following the clearance of the virus in the blood and other tissues of Zika-infected individuals.”

Barouch and colleagues infected 20 rhesus monkeys with Zika virus and noted the virus was cleared from peripheral blood within 7-10 days. However, they detected Zika virus in CSF for up to 42 days and in lymph nodes and colorectal biopsies for up to 72 days.

The team also showed that the generation of Zika virus-specific neutralizing antibodies by the monkeys’ immune systems correlated with the rapid control of the virus in plasma. However, these Zika-specific antibodies were not detected in CSF, and Barouch and colleagues speculate that this could be why the virus remained in CSF longer. The researchers also found that viral persistence in CSF correlated with the activation of a certain pathway known to be related to brain tissue development and brain malformations.

The findings suggest that virus remaining in the central nervous system may contribute to the neurological issues associated with Zika virus infection, according to the authors. While Zika virus causes little more than mild flu-like symptoms in most adults, it can cause severe fetal defects, such as microcephaly, if an infected pregnant woman passes the virus to her fetus. The virus has also been associated with the neurologic disorder Guillain-Barré syndrome in adults.

This work was funded by grants from the National Institutes of Health. (OD011095, AI028433, AI078881, AI095985, AI096040, AI100663, AI24377) and the Ragon Institute of MGH, MIT and Harvard.