While the world focuses on COVID-19 and its many debilitating complications, UK researchers and Brazilian collaborators have found that an infection from mosquito-borne viruses, namely the Zika and chikungunya viruses can cause stroke and extensive problems in brain function.These viruses mostly circulate in the tropics and are known to cause large outbreaks of rash and fever; however a stroke was more likely to occur in patients infected with the two viruses together.

At Hospital da Restauração in Recife, Brazil, around 200 patients were admitted with suspected neurological disease linked to Zika, chikungunya or both; of these, 148 had confirmation of viral infection on laboratory testing, around a third of whom had infection with more than one virus.

Most stroke patients admitted to the hospital (two thirds) were also found to be infected with more than one virus and had other stroke risk factors as well, including irregular and high blood pressure. This indicated that a stroke following Zika and chikungunya viral infection may most often be seen in those who are already at high risk.

“Our study highlights the potential effects of viral infection on the brain, with complications like stroke. This is relevant to Zika and chikungunya, but also to our understanding of other viruses, such as COVID-19, which is increasingly being linked to neurological complications,” said Dr. Suzannah Lant, a Clinical Research Fellow at the University of Liverpool, UK.

After analysing the new findings, Brazilian neurologist Dr. Maria Lúcia Brito Ferreira thinks the neurological complications from a viral infection – although rare – could require intensive care support in hospital, and still result in disability or even death.