Occurrence of Cryptosporidium oocysts in edible frogs (Rana species) sold for human consumption in Hanwa frog market, Zaria, Kaduna State, Nigeria

Abstract

Objective:To determine the occurrence of Cryptosporidium oocysts in edible frogs (Rana spp.) sold at the Hanwa frog market, Zaria, Kaduna State, Nigeria. Methods: A total of 117 frogs (Rana spp.) were randomly collected based on consent and availability at the market. The intestinal contents from the frogs were examined by staining flotation and sedimentation smears with modified Ziehl-Neelsen staining technique and microscopy of the oocysts. Results: Overall, 35.9% of frogs sampled from the Hanwa frog market were positive for Cryptosporidium oocysts. There were more Cryptosporidium oocysts detected by sedimentation test (28.2%) than flotation test (23.9%). There was no significant statistical association between sex of frogs and oocyst detection (χ 2 = 0.534 9, P > 0.05). Also, there was no correlation between the weights of frogs and the sizes of the Cryptosporidium oocysts detected (r = 0.010 9, P > 0.05). Nevertheless, female frogs (40%) and frogs within the weight range 170-219 g were more infected with Cryptosporidium (66.7%). Oocysts size range 6.10-7.00 µm had the highest frequency of 10 (23.8%). By size 28.2% of the oocysts detected suggested infection with Cryptosporidium parvum and Cryptosporidium maleagridis. Conclusions: This study has established that edible frogs (Rana spp.) sold at the Hanwa frog market for human consumption were infected with Cryptosporidium spp. which constitutes a valid public health risk especially for immunocompromised individuals.