Background: The evaluation of unexplained eosinophilia in an asymptomatic individual has always been a diagnostic challenge and requires understanding about a wide range of probable causative agents. Helminthic infestation and schistosomiasis are the main parasitic causes of eosinophilia. Therefore, the availability of simple and accurate diagnostic tests for detection of parasitic infections can prove to be valuable in early diagnosis and solving the mystery of unexplained eosinophilia.
Materials and methods: In the present study we attempt to find an association between relative eosinophilia and parasitic infections and also to find the parasites responsible for eosinophilia in a substantial number of cases. A retrospective study for the presence of eosinophilia was done on 621 cases positive for parasitic infestation.
Results: Among a total of 621 cases of parasitic infestation only 66 (10.6%) cases were found to have relative eosinophilia. The parasites found to be responsible for eosinophilia were Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercoralis, filarial worm and hook worm.
Conclusion: From the study it is concluded that eosinophilia is not a universal finding in cases with parasitic infestation. Although presence of eosinophilia can serve as one of the many diagnostic clues to look for the presence of helminthic infestation if other non-infectious causes of eosinophilia are ruled out.
Keywords: Ascaris lumbricoides; Helminths; Karnataka; Strongyloides stercoralis; Trichuris trichiura.