Introduction: Cases of gnathostomiasis (GNT) are mostly reported in Gnathostoma-endemic regions, including Southeast Asia, where raw fish dishes are popular. In general population, clinical presentations are variable, depending on the affected tissues but severe infection; for example, central nervous system involvement is not uncommon. In solid organ transplant recipients, data of gnathostomiasis is not known. In TTS 2016, we previously described unexpected kidney transplant (KT) cases of gnathostomiasis during investigation of eosinophilia. Following that experience, our center has been more vigilant in case identification. We herein described our experience of gnathostomiasis cases series diagnosed at our center for the past 10 years. 
Method: We reviewed KT cases diagnosed with GNT from 2016-2023 at Praram 9 hospital, Bangkok, Thailand. During the study period, KT candidates or KT recipients with clinical suspicious of tissue invasive parasitic infection were investigated. Patients tested positive for GNT serology (immunoblot, the department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand) were included and were followed prospectively for at least 1-year post transplantation. Patients’ demography, clinical characteristics, treatment and outcome were reviewed.
Results: A total of 18 GNT cases were identified. Majority (72%) were male and their median age was 51.5 (36-64) years old. Most (88.9%) were Thais. Two-third of the cases were identified post-KT, with the median time from KT to diagnosis of 8.4 months. None had pertinent clinical finding (no cutaneous lesion, deep visceral tissue, nor eyes/CNS involvement). One third were also seropositive for Strongyloides stercoralis. Over half had peripheral eosinophilia (p-EOS) but none had positive stool for ova and parasite. All cases received oral albendazole and/or ivermectin. Except for one case, p-EOS subsided within 3 months after the treatment. Six were seroconverted to negative test after the treatment. One year follow up did not reveal recurrent of the p-EOS. 
Conclusion: Gnathostomiasis is a previously under-recognized infection in solid organ transplant recipients, especially among patients in the endemic area. Work up for gnathostomiasis should be considered among cases in endemic area who present with new-onset p-EOS, before and after transplantation.