Opportunistic Infections in Biological Therapy, Risk and Prevention.

Patients being treated with biological therapies are at increased risk for serious infections, including opportunistic infections. Although more is known about opportunistic infection risk with older biologics, such as antitumor necrosis factor drugs, there is less knowledge of opportunistic infection risk with newer biological therapies. The incidence of certain opportunistic infections (tuberculosis, herpes zoster, pneumocystosis) has been rigorously evaluated in large observational studies. However, data are more limited for other infections (histoplasmosis, nontuberculous mycobacteria). Infectious morbidity and mortality may be preventable with screening and prophylaxis in select populations.