Whipple´s disease is rare. As a consequece, information about its epidemiology is fairly limited. Nevertheless, some data are available.

A regional study in Western Switzerland detected a total of 11 cases, diagnosed during 1971 and 1983 at an institute of pathology, serving a population of approximately 2 millions.( 1 )  From these crude data, an incidence of 0,4 / million / year can be estimated. 

A metaanalysis of all patients published in the world literature from 1907 until 1986, either in case reports or series, was performed. Data from a total of 619 published, along with 79 unpublished patients were evaluated. A striking predominance of male patients was noted (86%; vs. 14% females).  The mean age at the time of diagnosis was 49.1 yrs in men, and 51.0 yrs in women.( 2 )  Virtually all patients (98%) were white caucasian. Concerning occupation, farming trades were most prevalent among patients (22%).( 2 )  

A national study from Germany recruited a total of 110 patients diagnosed at five referral centers of GI pathology during time periods ranging from 1965 to 1995.( 3 )  Demographic features were found to have changed during  these decades. ( 3 )  (to read the abstract: click the buttom “Germany”)

Nowadays patients are diagnosed at a mean age of 57 years, and up to 30% are females. (click to the buttom: “Demography”)

References:

1.  Salomoni (1982)  La maladie de Whipple dans la Suisse occidentale entre 1960 et 1983.  Rev Med Suisse Romande 104: 655-666

2.  Dobbins WO III (1987).  Epidemiology. In: Whipple´s disease. CC Thomas, Springfield IL, 1987. 23-35

3.  von Herbay A, Otto HF, Stolte M, Borchard F, Kirchner T, Ditton HJ, Maiwald M (1997).  Epidemiology of Whipple's disease in Germany. Analysis of
    110 patients diagnosed 1965-1995.  Scand J Gastroenterol 32: 52-57