Hematozoa of Snakes in Queen Saovabha Memorial Institute

Abstract

During December 1997 to March 2001, 275 blood samples of snakes from eighteen species of four families, including Pythonidae, Colubridae, Elapidae and Viperidae, at Queen Saovabha Memorial Institute were examined for blood parasites. 111 samples (40.4%) were positive for hematozoa infections. The single infection (38.2%) were following genera : Hepatozoon (32.4%), Haemogregarina (4.0%) and trypanosome (1.8%). The incidence rates of mixed infections between Hepatozoon and Haemogregarina and between Hepatozoon and trypanosome were 0.4% and 1.8% respectively. Hepatozoon infections were found in mangrove snake (Boiga dendrophila melanota), mask-faced water snake (Homalopsis buccata), rainbow water snake (Enhydris enhydris), copper head racer snake (Elaphe radiata), common rat snake (Ptyas mucosus), Siamese spitting cobra (Naja siamensis), golden spitting cobra (Naja sumatrana), king cobra (Ophiophagus hannah), banded krait (Bungarus fasciatus), Malayan krait (Bungarus candidus), mangrove pit viper (Trimeresurus purpureomaculatus) and Siamese russell’s viper (Daboia russellii siamensis). There were three types of gamont of Hepatozoon sp., including small gamont (3.0 × 10.9 μm, n=120), medium gamont (3.3 × 14.8 μm, n=60) and the large gamont (3.9 × 15.0 μm, n=140). Haemogregarina infections were found in Burmese python (Python molurus bivittatus), mangrove snake, mask-faced water snake and rainbow water snake. The gamonts of Haemogregarina sp. were very large (7.6 × 15.2 μm, n=40). Trypanosomes were found only in mask-faced water snake and rainbow water snake. They were large flagelate hematozoa with 10-20 μm body width (14.1 ± 3.0 μm, n=120).