Persistent Eosinophilia and Strongyloides Infection in Montagnard Refugees after Presumptive Albendazole Therapy

Chronic helminth infections are common in refugee populations and may persist years after immigration. Asymptomatic Strongyloides stercoralis infection raises particular concern because of its potential for complications in immunosuppressed patients. We examined 172 Montagnard refugees resettled to Wake County, North Carolina from 2002 through 2003. Refugees were pretreated with albendazole for five days and screened for health conditions after arrival. Eosinophilia was present in 41 of 171 refugees at the first blood draw. Only 1 of 172 had a stool helminth (Fasciola) identified by microscopy. On repeat testing, 13 people had persistent eosinophilia. Results of serologic analysis for Strongyloides were available in 24 persons. Eosinophil counts decreased significantly after treatment with ivermectin in nine refugees (P = 0.039). Persistent eosinophilia, likely caused by Strongyloides infection, was common in this cohort of Montagnard refugees. Clinicians should understand the limitations of stool microscopy in diagnosis of strongyloidiasis, the limited effectiveness of albendazole in treating strongyloidiasis, and the importance of following-up refugees with persistent eosinophilia.