The following article is part of conference coverage from the Americas Committee for Treatment and Research in Multiple Sclerosis 2020 Forum in West Palm Beach, Florida. Neurology Advisor‘s staff will be reporting breaking news associated with research conducted by leading experts in neurology. Check back for the latest news from the ACTRIMS 2020 Forum.

WEST PALM BEACH — Patients who have been diagnosed with and treated for multiple sclerosis (MS) have an increased risk for any type of infection, and are more frequently hospitalized because of infections compared with their health counterparts, according to research presented at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) 2020 Forum held from February 27 to 29, 2020, in West Palm Beach, Florida. Results further showed that the highest increased risk was associated with renal tract infection.

Previous research has suggested that patients with MS have an increased risk for infection; therefore, the current study was designed to describe infection rates in this patient population using data from the United States Department of Defense database. Patients who were diagnosed with MS >1 year ago and were receiving treatment for this illness between January 2004 and August 2017 (n=8695) were matched with control patients without MS (n=86,934) by sex, age, and geographic region. Infections recorded after MS diagnosis were identified and incidence rates and incidence rate ratios (IRRs) of infection type and first infection were calculated.

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During a median 7 years of follow-up, participants with MS had higher infection rates (any infection, diagnoses combined) (IRR, 1.76; 95% CI, 1.72-1.80) and hospitalized infections (IRR, 2.43; 95% CI, 2.23-2.63). Compared with matched controls, patients with MS had a higher incidence rate of first renal tract infection (IRR, 1.88; 95% CI, 1.81-1.95); skin infections (IRR, 1.51; 95% CI, 1.45-1.58); fungal infections (IRR, 1.47; 95% CI, 1.41-1.53); pneumonia and influenza (IRR, 1.48; 95% CI, 1.40-1.56); as well as other types of infection including helminthiases, rickettsioses, spirochetal diseases, nonsyphilitic and nongonococcal venereal diseases, and parasitic infections and infestations (IRR, 1.68; 95% CI, 1.61-1.75).

Incidence rate ratios of eye, ear, respiratory, throat, and viral infections were only marginally elevated. Results also demonstrated that rates of renal tract infections were more than 4-fold higher among women compared with men in both groups, but the IRR was higher in men (IRR, 2.47; 95% CI, 2.22-2.75) than women (IRR, 1.90; 95% CI, 1.83-1.98).

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The investigators concluded, “Treated MS patients have an increased risk of any infections. Hospitalized infections were also increased in MS patients. Most infection types were increased in MS patients with the highest risk associated with renal tract infections.”

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Jick S, Persson R, Ulcickas M, et al. Increased risk of infections in patients diagnosed with and treated for multiple sclerosis: A study using the US Department of Defense Database. Presented at: ACTRIMS Forum 2020; February 27-29, 2020; West Palm Beach, FL. Abstract P086.