Non-Neurology Providers Detect Most Infections in Multiple Sclerosis

The majority of infections in multiple sclerosis (MS) are reported in non-neurology practices, according to study results presented at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) Congress 2025, held in Barcelona, Spain from September 24 to 26, 2025.

Patients with MS are at increased risk for infections, but little is known about how often symptoms first present to neurology vs non-neurology providers. Researchers compared infection diagnosis rates between neurology and non-neurology practices in patients with MS receiving disease-modifying therapy (DMT).

The researchers used US claims data from 2017 to 2024. Eligible participants were newly diagnosed with MS, aged between 18 and 64 years, and had received DMT for at least 90 days. The index date was defined as the first DMT claim. Infections were identified using diagnostic codes, and serious infections were classified as those requiring hospitalization or intravenous antibiotics.

A total of 69,148 patients with MS (mean age, 44.1 years; 72% women) were included, with 316,497 infection events reported. More than 80% of the cohort began DMT within 1 year of MS diagnosis. Non-neurology providers first reported 98% of these infections. The most common infections were urinary tract infections (UTIs) and COVID-19, reported at neurology (21% and 8%) and non-neurology (31% and 12%) practices, respectively. At neurology practices, herpes zoster, chronic sinusitis, and cystitis followed, while at non-neurology practices, acute sinus infections, upper respiratory infections, and dermatophytosis were more common.

There were 21,416 serious infections reported, 99% of which were identified by non-neurology providers. At neurology practices, UTIs (41%) and sepsis (20%) were most common, followed by COVID-19, pneumonia, and other bacterial infections. At non-neurology practices, UTIs (33%) and sepsis (14%) were most common, followed by cellulitis and acute lymphangitis, cystitis, and pneumonia.

Among patients with MS who had infections reported by non-neurology providers, 16% saw a neurology provider within 30 days. Of these, 4% had a matching diagnostic code for the same infection, and 9% for serious infections. These rates were higher when neurology visits occurred within 7 days of the initial infection event.

The researchers concluded, “Most (≥98%) infections in pwMS [people with multiple sclerosis] are first reported by non-neuro providers, highlighting the importance of communication between different providers and patients to accurately assess patient status and DMT safety to improve patient outcomes.”

Disclosures: This research was supported by Biogen. Multiple authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.