Common Infections Tied to Increased Stroke Risk in Children
Several new studies have concluded that common infections, such as the cold or chickenpox, could increase a child's risk of stroke. These findings suggest that vaccines could be more important in protecting young children than previously believed. However, the studies' researchers stated that strokes are very rare in children and that the results are preliminary.
"Clearly, infections are very common and stroke is very rare in children. What's going on is that infections are acting as a trigger for stroke in children who are likely predisposed to stroke," Dr. Heather Fullerton, an author involved with the three studies, stated.
The findings were the results of three studies that were all a part the Vascular Effects of Infection in Pediatric Stroke (VIPS) study. The studies included 310 children in the stroke group and 289 children in the control group. The children averaged around 7.5 to eight years old. VIPS is the largest study on pediatric stroke to be funded by the National Institutes of Health (NIH). It includes 40 centers located on five continents.
In the first study, the researchers reported that children who had an infection less than one week before they suffered from a stroke had a 6.5 times increased risk of stroke. For this sample set, the most common type of infection was an upper respiratory infection. The researchers also reported that for children who received a few or none of the commonly recommended vaccines had a 6.7 times increased risk of stroke. This study found that the vaccines for measles-mumps-rubella (MMR), polio or pneumococcus were particularly protective against stroke.
"Children who'd had a stroke were most likely to have had a recent infection compared to controls [children without stroke]," Fullerton, who is a director of the Pediatric Stroke and Cerebrovascular Disease Center at the University of California, San Francisco, said according to Philly. "There was a particularly strong association for an infection in the week before a stroke, almost a sevenfold increase in the risk of stroke."
In the second study, the researchers tested various viruses that included herpes simplex virus 1 and 2, cytomegalovirus, Epstein-Barr virus, and varicella zoster virus (chickenpox). The researchers discovered that 41 percent of the children who had a stroke also had evidence of acute herpes virus. In the third study, the researchers reported that 10 out of the 162 children in the stroke group had parvovirus B-19. This infection was not apparent at all in the group of children who did not suffer from a stroke.
"It was a surprise to find so many parvovirus infections in the stroke group. We will be following up on this study," Fullerton commented.
"These were case-controlled studies looking at people with stroke versus controls -- you're not dealing with the general population. So, it should be noted that although there are strong associations, stroke in children is still a very uncommon thing," added Dr. Kenneth Bromberg, director of the Vaccine Research Center and chairman of the department of pediatrics at the Brooklyn Hospital Center, in New York City. "The point of these studies is to better understand stroke, not to alarm the public."
The findings are set to be presented at the American Stroke Association's International Stroke Conference 2014.