Could parasitic infection protect against multiple sclerosis development?

Having toxoplasmosis, which is an infection by the parasite toxoplasma gondii, may help to protect against developing multiple sclerosis (MS), according to a new review study.

Toxoplasmosis occurs when a person ingests undercooked meat that’s contaminated with the parasite or comes into contact with infected cat feaces. It’s usually relatively harmless and easily treated. It has previously been shown to promote anti-inflammatory, immunosuppressive results in animal studies.

Researchers looked at eight studies, which featured 752 people with MS, and 1,282 people without the condition, who were in control groups. Two of the studies took place in Europe, three in Asia and one in the US.

Researchers found that people who had had toxoplasmosis were 32% less likely to develop MS than those who had never been infected. They said that while the findings support the theory that this type of infection is a protective factor against MS, more studies are needed to confirm it, to discover if it also helps with disease progression, and to understand the mechanisms behind the effects. Such information could help develop new therapies for people with MS, the researchers believe.