Cryptosporidium varanii Infection in Captive Leopard Gecko (Eublepharis macularius) and Its Association with Wasting Syndrome in Thailand

Cryptosporidiosis is a globally important protozoan disease that causes severe gastrointestinal illness in immunocompromised humans and animals and has been associated with chronic wasting and death in reptiles. This study investigated the role of <i>Cryptosporidium</i> infection in wasting syndrome among captive leopard geckos from a commercial breeding facility in Chiang Mai, Thailand. Thirty-five geckos housed in twenty-three enclosures were observed for four months, with fecal samples collected over three consecutive days every two weeks and pooled for molecular analysis. Clinical evaluations included body weight (BW), tail diameter, and body condition score (BCS) to assess wasting. Nested PCR targeting the 18S rRNA gene and subsequent sequencing were performed. <i>Cryptosporidium</i> was detected in 51.43% of geckos and 52.17% of enclosures, while 20% exhibited wasting syndrome. BLAST (v. 2.17.0) and phylogenetic analyses identified <i>C. varanii</i>, which showed 100% identity with isolates from leopard geckos in Spain and from snakes in Thailand and China. Multivariable logistic regression demonstrated a significant association between <i>Cryptosporidium</i> infection and wasting syndrome (OR = 11.15, 95% CI: 1.78-69.98, <i>p</i> = 0.027), with persistent oocyst shedding observed. This study provides new insights into <i>C. varanii</i> infection among leopard gecko breeders in Thailand and highlights the potential for infected breeding stock to disseminate <i>Cryptosporidium</i>, underscoring the need for enhanced awareness, surveillance, and biosecurity measures across Thailand and the Asia-Pacific region.