Survey of Angiostrongylus cantonensis in rats and giant African land snails in Phitsanulok province, Thailand

Objective: To survey the Angiostrongylus cantonensis (A. cantonensis) or the rat lungworm in a rat, definitive host, and in a giant African land snail (Achatina fulica), the intermediate host, in Phitsanulok, Thailand. Methods: Rats and giant African land snails were captured from Tha Pho sub-district, Phitsanulok, Thailand. Rats were killed and examined for adult A. cantonensis. The artificial digestion method following Baermann technique were used for isolation third stage larvae of A. cantonensis. Results: Sixty-two rats were captured and they were identified as Rattus argentiventer, Rattus rattus (R. rattus), Bandicota savilei. and Bandicota indica but only one animal (R. rattus) of 62 rats (1.61%) was positive with adult worm of A. cantonensis. The third stage larvae of A. cantonensis were examined on 307 Angiostrongylus fulica snails. It was found that the overall infection rate was 12.38% (38 infected out of 307 Achatina snails). Conclusions: This study demonstrates that A. cantonensis is available in the natural hosts of Phitsanulok. This suggests that the transmissions of this parasite to human may occur in this region.