According to this article, it seems that a group of viruses known for their circular genome found in a few severe cases in Vietnam and Malawi could be linked to neurological diseases such as brain inflammation. This group of viruses is referred to as cycloviruses. More studies would need to be done to prove the connection between the two.

For the cases in Vietnam, vexed researchers kept coming up short with answers for patients with infected central nervous systems. After considerable diagnostic tests, half of the patients with these types of infections were found with pathogens in them. H. Rogier van Doorn, a clinical virologist, with the help of some fellow workers decided to use next-generation sequencing to hopefully uncover unknown pathogens. After using this latest technique on samples of cerebrospinal fluid from one hundred plus patients, one sample result returned with an interesting clue. A viral sequence from the Circoviridae family, from which cycloviruses are found, was discovered. The researchers went back to the original samples and specifically tested for Circoviridae and uncovered two samples with it. Then, they tested an additional six hundred and forty-two patients with central nervous system infections. The results yielded that about four percent of the patients had this viral sequence in them. Scientists have termed this virus cyclovirus-Vietnam, or CyCV-VN.

As for the cases in Malawi located in southeast Africa, a team at Erasmus MC in the Netherlands has found a similar situation. After trying to learn the cause or causes of paraplegia in a few cases, they discovered a new form of cyclovirus. With these results prompting them, the scientists assessed fifty-eight new paraplegia patients and learned that this virus was in fifteen percent of a fifty-four serum sample. It was also in ten percent of forty cerebrospinal fluid samples.

Even with the results of both of these studies, it is not enough to conclude that cycloviruses are the cause of these diseases. Eric Delwart from the Blood Systems Research Institute in San Francisco states that the virus could actually be making the original infections worse instead of causing them. The next step in figuring this out would be to grow them and test on animals.