Infections in patients with multiple sclerosis: Implications for disease-modifying therapy

Patients with multiple sclerosis have an increased risk of infections compared to the general population. The increased risk has been described for decades and is not alone attributed to the use of disease-modifying drugs, but secondary to the disability. The introduction of more potent immunomodulatory drugs may cause an additional challenge, and depending on the mechanism of action, a treatment-induced increased risk of bacterial, viral, fungal or parasitic infections is observed. The choice of treatment in the individual patient with infections and multiple sclerosis must be guided by the drugs' specific mechanism of action, the drug-specific risk of infection and comorbidities. Increased monitoring and follow-up through treatment registries is warranted to increase our understanding and thereby improve management.