(CN) - Scientists continue to rack up strong evidence supporting a connection between the Zika virus and a rare nervous system disorder that can result in paralysis.
Researchers from Johns Hopkins School of Medicine reported their findings after analyzing 68 Colombians with symptoms of Guillain-Barre syndrome, a post-infectious immune condition that affects a person's nervous system and causes muscle weakness, sensory deficiencies and paralysis in rare cases. Their findings were published Wednesday in the New England Journal of Medicine.
While the primary concern surrounding Zika has been its connection to birth defects, the new evidence strengthens speculation within the scientific community that an increased number of Guillain-Barre cases is related to the outbreak of the mosquito-borne Zika virus.
"In 2013 and 2014, an increase in the number of cases of the Guillain-Barre syndrome was observed during an outbreak of Zika infection in French Polynesia. Recently, clusters of the Guillain-Barre syndrome and microcephaly have been spatially and temporarily related to the current outbreak of Zika infection in the Americas," the authors write in the study.
The team of Johns Hopkins researchers worked with colleagues in Colombia to evaluate patients with suspected neurological problems associated with Zika. The team tested blood, cerebrospinal fluid and urine samples from 42 of the patients with symptoms of Guillain-Barre, finding after some evaluation that urine is the most reliable fluid for diagnosing Zika infections in patients with Guillain-Barre.
Seventeen patients' urine tested positive for Zika. Another 18 had no evidence of the virus in their urine but showed the immunological footprint of Zika, with virus-specific antibodies in their blood or spinal fluid.
The study participants were mostly adults, 38 men and 30 women. Almost all of the patients displayed two or more clinical symptoms of Zika infection, which can include joint paint, fever, headache and conjunctivitis.
Almost half of the patients complained of neurological symptoms within four days of the onset of Zika symptoms, according to researchers. This is an unusually fast response for people who develop Guillain-Barre symptoms due to other viral infections such as influenza and herpes viruses, the researchers said.
Lead author Carlos Pardo, associate professor of neurology and pathology at Johns Hopkins, said the study is believed to be the largest of its kind to analyze the role of Zika infection in elevated rates of Guillain-Barre so far. However, he also cautioned that while the study demonstrates a viral and biological association between Zika and Guillain-Barre, it does not reveal the biological mechanisms through which the virus might initiate an immune attack on the nervous system.
The team continues to collect clinical data and samples from patients at six Colombian hospitals, but their work is restricted due to the limited availability of resources and the severe and ongoing Zika outbreak in South America.Follow @@SeanDuffyCNS
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