A case report of Brugian filariasis outside an endemic area in Thailand.

A 2-year-old boy living outside the endemic area of lymphatic filariasis in Surat Thani Province, Thailand, developed a high fever. To investigate the cause of his presenting symptoms, blood was collected and microfilariae were detected and identified as Brugia malayi using thick blood smear staining. The sources of the infection were investigated. Microfilariae from two domestic cats residing in the boy's village were detected and identified as B. pahangi using a high-resolution melting real-time polymerase chain reaction analysis. The possible sources of this cryptic infection are discussed.