A new research published in the Lancet Neurology has recently found that a deadly combination of two mosquito-borne viruses may be a trigger for stroke.
The study shows stroke could be caused by either virus alone, was more likely to occur in patients infected with the two viruses together.
Stroke occurs when one of the arteries supplying blood to the brain becomes blocked. The risk of stroke is known to be increased after some types of viral infection, like varicella zoster virus, which causes chickenpox and shingles, and HIV.
Stroke is also being recognised increasingly as a complication of COVID-19. This has important implications for the investigation and management of patients with viral infection, as well as for understanding the mechanisms of disease.a
In total 1410 patients were screened and 201 recruited over a two-year period at Hospital da Restauração in Recife, Brazil. Comprehensive PCR and antibody testing for viruses was carried out in Fiocruz laboratories.
Of the 201 patients admitted with suspected neurological disease linked to Zika, chikungunya or both, 148 had confirmation of infection on laboratory testing, around a third of whom had infection with more than one virus.
The median age of patients was 48, and just over half the patients were female. Only around 10 per cent had fully recovered at discharge, with many having ongoing issues like weakness, seizures, and problems in brain function.
Of the stroke patients, who were aged 67 on average, around two thirds had infection with more than one virus. Many of the people who had a stroke had other stroke risk factors, such as high blood pressure, indicating that stroke following Zika and chikungunya viral infection may most often be seen in those who are already high risk.
Dr Maria Lúcia Brito Ferreira, neurologist and head of department at Hospital da Restauração, leading the Brazilian team said: “Zika infection most often causes a syndrome of rash and fever without many long-term consequences, but these neurological complications—although rare—can require intensive care support in hospital, often result in disability, and may cause death.”
Dr Suzannah Lant, a Clinical Research Fellow at the University of Liverpool, who worked on the study explained: “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.”
Senior author Professor Tom Solomon, Director of the National Institute for Health Research Health Protection Research Unit in Emerging and Zoonotic Infections at the University of Liverpool said: “Although the world's attention is currently focused on COVID-19, other viruses that recently emerged, such as Zika and chikungunya, are continuing to circulate and cause problems. We need to understand more about why some viruses trigger stroke, so that we can try and prevent this happening in the future.”
