Tropheryma whipplei Infection (Whipple Disease) in the USA

Background: Whipple disease (WD) is an infection caused by the bacterium Tropheryma whipplei (TW). Few cases have been reported in the USA. Aims: To report on the demographics, clinical manifestations, diagnostic findings, treatment, and outcomes of TW infection. Methods: Cases of TW infection diagnosed from 1995 to 2010 were identified in three US referral centers and from 1995 to 2015 in one. Definite classic WD was defined by positive periodic acid-Schiff (PAS) staining and probable WD by specific positive TW polymerase chain reaction (PCR) of intestinal specimens. Localized infections were defined by a positive TW PCR result from samples of other tissues/body fluids. Results: Among the 33 cases of TW infections, 27 (82%) were male. Median age at diagnosis was 53 years (range 11–75). Diagnosis was supported by a positive TW PCR in 29 (88%) and/or a positive PAS in 16 (48%) patients. Classic WD was the most frequent presentation (n = 18, 55%), with 14 definite and 4 probable cases. Localized infections (n = 15, 45%) affected the central nervous system (n = 7), joints (n = 4), heart (n = 2), eye (n = 1), and skeletal muscle (n = 1). Blood PCR was negative in 9 of 17 (53%) cases at diagnosis. Ceftriaxone intravenously followed by trimethoprim and sulfamethoxazole orally was the most common regimen (n = 23, 70%). Antibiotic therapy resulted in clinical response in 24 (73%). Conclusions: TW infection can present as intestinal or localized disease. Negative small bowel PAS and PCR do not exclude the diagnosis of TW infection, and blood PCR is insensitive for active infection.