Mammomonogamus roundworm (Nematoda: Syngamidae) recovered from the duodenum of a Thai patient: a first and unusual case originating in Thailand.

A pair of Mammomonogamus laryngeus roundworms in copula was recovered from the duodenum of a 72-year-old male Thai patient from Kanchanaburi Province. Eggs were also found in the stool of the patient. This is the first case of Mammomonogamus infection originating in Thailand, as the previous two reports from Thailand attributed the infection as originating in Malaysia.