Eosinophilia: clinical significance in HIV-infected individuals

This study was conducted to determine the relationship between eosinophilia and parasitic infection in HIV-infected individuals. HIV-positive patients attending an HIV clinic in Birmingham were recruited and classified as either eosinophilic (>400 eosinophils/mm(3)) or non-eosinophilic. A demographic and parasitic risk history was taken and clinical examination was performed. Urine and stool were examined for parasites, and blood samples taken for parasite serology. A total of 266 patients (96 eosinophilic and 170 non-eosinophilic) were recruited. Of 64 eosinophilic patients who had a stool examination, one (1.6%) was positive for both Strongyloides larvae and schistosomal eggs. Urine microscopy was negative in the 245 patients (88 eosinophilic, 157 non-eosinophilic) from whom a sample was available. Two hundred and sixty-three patients underwent serological investigation (96 eosinophilic and 167 non-eosinophilic): 13 (4.9%) were positive for schistosomiasis and three (1.1%) positive for Strongyloides. A significant association between eosinophilia and positive schistosomal serology was found (P = 0.003): 11 (10.5%) were eosinophilic patients, while only four (2.3%) were non-eosinophilic patients. Eosinophilia was associated with a low nadir CD4 count (P = 0.021) and prior AIDS-defining illness (P = 0.041). In all, 7.8% of patients from a developing country and 5.3% of patients from a developed country with a travel history had positive parasitic serology. Eosinophilia in HIV-infected patients was significantly associated with positive serology for schistosomiasis, low nadir CD4 count and prior AIDS-defining illness. Geographical exposure is also an important determinant of positive parasitic serology.