Experimental infection of rabbits with Fasciola gigantica and treatment with triclabendazole (TCBZ) or BT6: parasitological, haematological and immunological findings.
The responses of rabbits experimentally infected orally with 25 Fasciola gigantica metacercariae each, to treatment with triclabendazole (TCBZ) in a single oral dose of 10 mg/Kg body weight or with the newly synthesized drug (BT6) in repeated oral doses of 500 mg/Kg for 3 consecutive days, were monitored by faecal egg and fluke counts and the enzyme-linked immunosorbent assay (ELISA), both treatments at 4-, 8- and 12- weeks of infection. In all infected rabbits, eggs appeared in the faeces between 10 and 16 weeks post-infection (P1) and Were egg-negative in the TCBZ-treated animals. Compared with the infected untreated control (group B), the reduction in the fluke burdens were 93.75,100 and 100% in TCBZ-treated rabbits (groups C, D and E), respectively and 33.33, 27.08 and 27.08% in the BT6 treated groups F, G and H, respectively. Total red blood corpuscle (RBCs) counts, haemoglobin (Hb) concentration and packed-cell volume (PCV) values in rabbits (group B) indicated the presence of moderate anaemia from the start of infection with a significant decrease from 10-12 weeks onwards. RBCs count, Hb and PCV values from groups C, D and E were significantly higher (p < 0.001) than in those from group B on week 10, 8 and 10 PI, respectively. The increasing was continued till week 16 PI. By two weeks PI there was significant eosinophilia in infected rabbits, maintained at 4 and 6 weeks PI then dropped up to 8 weeks but still statistically higher than the control values. The ELISA detected antibodies against F. gigantica as early as week 2 PI, rising to high levels 6, 10 and 12 weeks later in groups C, D and E, respectively, whilst peaked at 10 weeks in BT6 treated animals, then tended to drop but remained positive through 16 weeks. We conclude TCBZ is a potent fasciolicidic drug. Eosinophilia and anaemia might be indicators for fascioliasis. The ELISA with adult fluke excretory - secretory (ES) antigens could be a feasible method for the diagnosis of experimental fascioliasis in rabbits and post-treatment monitoring.
Sherif
N
N
Zoology Department. Faculty of Science, Suez Canal University Ismailia, Egypt.
Shalaby
I
I
Abdel Moneim
M
M
Soliman
M
M
D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D004534:Egypt; D005209:Fasciola / Q000187:drug effects* / Q000469:parasitology; D008297:Male; D011817:Rabbits / Q000097:blood* / Q000469:parasitology*; D000077682:Triclabendazole
D000871:Anthelmintics; D001562:Benzimidazoles; D000077682:Triclabendazole