Objective: To establish a rapid, simple and reliable assay with samples of whole blood for diagnosis and epidemiological study on hydatidosis.
Methods: The dot immunogold filtration assay kit was developed and potato agglutinin was applied to blot blood quickly.
Results: Among 1 678 persons from prevalent area, the positive rate of DIGFA was 8.469 while that of image examination was 3.04%. Both DIGFA and image technique showed positive results in 43 cases. 8 cases with positive image but negative DIGFA were followed up for 16 months, which turned out that 3 cases with necrotic hydatid cysts, 2 cases with calcified hydatid cysts and 2 cases with benign hepatic cysts. 99 cases with positive DIGFA but negative image were also followed up for 16 months, 3 pulmonary hydatid cases were confirmed. Among 38 cases proved by operation and histopathology, the positive rate of DIGFA was 89.5%. 52 samples from non-prevalent area all showed negative DIGFA. Another 40 non-hydatidosis cases (10 samples of hepatic hemangioma, 10 of non-parasitic cysts of liver, 10 of primary hepatic carcinoma, 6 of pulmonary tuberculosis, 4 of lung cancer) also showed negative DIGFA. 190 samples were selected randomly and detected blindly by DIGFA with whole blood, DIGFA with serum and ELISA with serum to evaluate their diagnostic effect with no statistical difference (P>0.05).
Conclusion: The DIGFA kit is rapid, simple and reliable in epidemiological study of hydatid disease, with an advantage of using whole blood sample instead of serum.