infection associated with lymphoma or mimicking lymphoma in two cohorts of Swedish patients.

The tick-borne bacterium () causes latent infections that can become symptomatic when B-cell defenses are compromised. We investigated the prevalence of in two cohorts of Swedish patients: a prospective cohort ( = 186) evaluated for lymphoma and a retrospective cohort ( = 198) diagnosed with seven lymphomas. Samples were tested for by PCR. Nine of 116 patients (7.8%) diagnosed with lymphoma in the prospective cohort, and 7/198 (3.5%) in the retrospective cohort had a concomitant infection. Indolent lymphomas, particularly marginal zone lymphoma (9.3%), were frequently coupled with infection. Males had higher risk of having lymphoma and infection. was diagnosed in 3.2% of patients without lymphoma, making it the most common infectious differential diagnosis for possible lymphoma. This emerging pathogen should therefore be considered as a differential diagnosis for patients with suspected lymphoma in -endemic regions.