Rates of Zika virus have been increasing in many countries, with infection primarily through mosquito bites. The disease is associated with several ill-health effects. To add to those previously reported, an association with a new autoimmune disorder has been reported.
Zika virus is a member of the Flaviviridae virus family. In most people, the disease is asymptomatic; in around one in four people the disease causes a mild illness known as Zika fever, which lasts for around four to seven days. In addition to fever, the symptoms can include rashes, joint pain, and conjunctivitis.
The disease, discovered back in 1947, is transmitted by daytime-active mosquitoes of the genus Aedes. The possibility of catching the disease rises proportionately with the numbers and distribution of carrier mosquitos.
Outside of the mild fever, the disease poses a risk to pregnant women, where there is a connection with infected women and babies born with abnormally small heads and brain defects, a condition called microcephaly. Furthermore, Zika virus disease could be linked to a form of paralysis called Guillain-Barré syndrome.
Now, it appears, Zika virus could be linked to an autoimmune disorder that attacks the brain’s myelin in a similar fashion to multiple sclerosis. This is based on research undertaken by Dr. Maria Lucia Brito Ferreira who works with Restoration Hospital in Recife, Brazil. Here it was found, in a low number of people that some who become infected with Zika develop specific neurologic symptoms. One condition noted to develop was acute disseminated encephalomyelitis, which attacks the brain and spinal cord where it damages white matter. Although not fatal, those infected took around 6-months to recover. The low level cases matches the few reported cases linking Zika to Guillain-Barré syndrome.
In a research note, Dr. Ferreira states that her findings do not “mean that all people infected with Zika will experience these brain problems. Of those who have nervous system problems, most do not have brain symptoms.” Nonetheless, the findings do raise further concerns about the effects of the virus on the human brain.
The results of the new Zika disease association have yet to be published, although the results of a study are set to be reported to the April 15 meeting of the American Academy of Neurology in Vancouver, Canada.