Between 2002 and 2006 in the Department of Tropical and Parasitic Diseases of the Medical University of Gdansk 40 hospitalized patients were suspected of schistosomiasis on the basis of clinical manifestations, epidemiological data and positive serology tests (ELISA IgG).
In spite of multiple tests, schistosoma eggs were not identified neither in stool nor in urine of the patients.
Histopathological examinations of liver and colon or bladder mucosal biopsy have not revealed schistosoma eggs in chosen patients.
Diagnosis confirmation in case of negative parasitic tests requires serologic tests for schistosomiasis. ELISA serology tests for antibodies class G were performed in all 40 patients. In some cases the results were dubious – index in the upper limit or only slightly elevated. In those cases, cross reactions with Plasmodium spp. were taken into account. In 10 patients, serologic index for schistosomiasis was elevated during or a few weeks after treatment for malaria. In control tests, 4-8 weeks after the first examination, serologic indexes for schistosomiasis were significantly lower or normal without specific treatment with praziquantel (Biltricide, Cesol). Seven patients were lost from follow up.
Because of diagnostic difficulties confirmation tests with Immuno-Blot IgG were introduced to verify ELISA. After final clinical and serologic analysis, human schistosomiasis was diagnosed in 23 patients who were treated with success.

¹Inter-Faculty Institute of Maritime and Tropical Medicine
Director: Prof. Przemysław Myjak, PhD
²Department of Tropical and Parasitic Diseases, Medical University of Gdańsk

Address for correspondence:
Dr Jolanta Goljan, MD
Institute of Maritime and Tropical Medicine,
Powstania Styczniowego 9 B, 81-519 Gdynia, Poland
Fax 58-622 3354, E-mail: jolantag23@wp.pl