Diagnostic evaluation of newly arrived asymptomatic refugees with eosinophilia

Refugees may arrive for resettlement with asymptomatic parasitic infections, and eosinophilia may be the only clue to the presence of infection. Our aim was to determine the prevalence of eosinophilia and develop a standardized approach to the evaluation of asymptomatic refugees with eosinophilia.

We reviewed the medical records of refugees seen from October 1998 through May 2002 at Boston Medical Center. Data examined included age, country of origin, absolute eosinophil count, results of stool ova and parasite testing, and results of serological testing for Strongyloides stercoralis, Schistosoma species, and filaria.

Eosinophilia--defined as an absolute eosinophil count of >or=450 cells/microL--was present in 266 (12%) of 2224 refugees. Patients with eosinophilia ranged in age from 2 months to 81 years and had arrived from Africa, Eastern Europe, Southeast Asia, South America, the Caribbean, and the Middle East. Absolute eosinophil counts ranged from 450 to 3224 cells/microL. Pathogens were identified in stool samples of 76 (29%) of 265 patients. Serological testing for S. stercoralis, Schistosoma species, and/or filaria was done for 120 (45%) of 266 patients. Results of serological testing were positive for S. stercoralis in 45 (39%) of 115 patients, for Schistosoma species in 15 (22%) of 67 patients, and for filaria in 18 (51%) of 35 patients. Serological evidence of parasitic infection was seen at all levels of eosinophilia and in patients with and without pathogens identified in their stool samples.

Systematic evaluation for parasites in asymptomatic, newly arrived refugees with eosinophilia should include stool ova and parasite examination, serological examination for S. stercoralis for all patients, and serological examination for Schistosoma species and filaria in patients from regions where these organisms are endemic.