Klumph M, Hoeynck B, Baumgardner DJ.Cryptococcal antigen testing in an integrated medical system: Eastern Wisconsin. Poster presented at: Aurora Scientific Day; May 22, 2019; Milwaukee, WI.
Poster presented at: Aurora Scientific Day; May 22, 2019; Milwaukee, WI.
Background: Cryptococcosis is an environmentally acquired endemic fungal infection causing serious disease in usually immunocompromised hosts. Environmental associations of pathogenic species include certain trees, soils, bird guano, and parks. Little is known about the frequency and distribution of cryptococcosis in Wisconsin. Cryptococcal antigen detection (CrAg) test is more than 90% sensitive and specific and is frequently used to screen patients with likely disease.
Purpose: We aimed to explore the geodemographic and clinical features of Wisconsin patients tested with CrAg.
Methods: We conducted a retrospective review of all patients at Aurora Health Care having CrAg testing from January 2013 to April 2017. Patients with 1 or more positive CrAg test(s) were always considered positive, and basic demographic and clinical features were used from the first identified positive test. For patients always testing negative, clinicodemographic features were taken from the first test. Basic descriptive statistics were computed and chi-squared or t-tests were used as appropriate. Binary logistic regression was used for multivariable analysis.
Results: A total of 1465 CrAg tests (741 on serum, 723 on cerebrospinal fluid, 1 other) were performed on 1211 unique patients (mean age: 53.7 ± 16.5; female sex: 50.2%; white race: 73.9%) during this time. At least 1 CrAg test was positive in 23 of 1211 patients (1.9%); 21 of 23 (6 transplant patients, 5 HIV, 4 malignancy, 6 other) were immunocompromised (vs 13 predicted; P<0.001). Positive patients were disproportionately male (19 of 23 [3.2% of all those tested] vs 4 female [0.7% of all those tested]; P=0.002) and nonwhite (12 of 23 [3.8% of all those tested] vs 11 white [1.2% of all those tested]; P=0.012). These associations, but not age, were significant independent predictors in multivariable models. Overall, 17 separate zip codes had 1 positive case, 2 city of Milwaukee zip codes had 3 each, with the closest two patients living 193 meters apart; no other case clustering or close proximity to waterways was observed (41% were less than 162 m from green space, similar to historical controls). Positive patients were more prevalent in Milwaukee (2.9% of those tested vs 1.6% of all those tested in rest of state), but this was not significant (P=0.21).
Conclusion: Among all CrAg-tested patients, male gender, nonwhite race/ethnicity, and immunocompromised status, not natural environmental features, predicted positive tests. To our knowledge, this is the first report regarding the distribution of cryptococcosis in Wisconsin.