The Risks of Ticks and Mosquitoes for Patients on Rituximab

Know the risks of vector-borne diseases when prescribing immunosuppressive drugs and educate your patients about ways to prevent tick and mosquito bites.

Ticks, Mosquitoes, and Patients on Rituximab: 5 Things to Know

As the weather heats up, counsel your patients about diseases associated with mosquito and tick bites, particularly patients taking immunosuppressive drugs such as rituximab or other B cell– depleting immunotherapies. These drugs are often prescribed for oncologic, rheumatologic, and neurologic conditions and can help improve patients' quality of life. However, they can also put patients at risk for severe disease from mosquito- and tickborne viruses.

Here are five things to know about prescribing this class of drugs and counseling your patients about how to prevent arboviral infections like West Nile virus.

1. Patients on B cell–depleting immunotherapies are at high risk for severe disease from arboviral infection.

A recent case series of 21 patients on rituximab who were diagnosed with arboviral disease found that all patients had neuroinvasive disease, including encephalitis or acute flaccid myelitis. Fifteen of 19 (79%) patients whose outcome was reported died from complications of their arboviral disease. Those who survived often had long-term disabilities like cognitive and motor dysfunction.

B cell–depleting immunotherapies such as rituximab and ocrelizumab are effective therapies for many oncologic, rheumatologic, and neurologic conditions, but they can also place patients at risk for severe infectious diseases because of the profound B-cell depletion resulting from these therapies.