Diagnosis of a Trypanosoma lewisi-like (Herpetosoma) infection in a sick infant from Thailand

• DOI: 10.1099/jmm.0.47222-0
• Publication Date: 2007-07-20T17:52:59Z
• Authors: Nachai Sarataphan; Montakan Vongpakorn; Bandit Nuansrichay; Nonglux Autarkool; Tiemjan Keowkarnkah; Pranee Rodtian; Roger W. Stich; Sathaporn Jittapa...
• Keywords: Male; Trypanosoma lewisi; Molecular Sequence Data; Infant; Parasitemia; Thailand; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; RNA, Ribosomal; Trypanosomiasis; DNA, Ribosomal Spacer; Animals; Humans; RNA, Protozoan

Trypanosomes were observed in a peripheral blood smear from a 45-day-old Thai infant displaying fever, anaemia, cough and anorexia. Human trypanosomiasis is not endemic to Thailand, so parasite identification was undertaken to determine likely sources of the infection. Several morphological parameters of the trypanosomes were similar to those of Trypanosoma evansi and statistically different from those of Trypanosoma lewisi-like parasites from a naturally infected indigenous rat. However, duplicate PCR assays with primers flanking trypanosome rRNA internal transcribed spacer 1 (ITS1) resulted in amplicons of ~623 bp that corresponded to the expected size for T. lewisi-like parasites. The ITS1 sequence from the infant's blood was 98 and 49 % identical to T. lewisi and T. evansi sequences, respectively. Based on molecular results, it was concluded that the infant was infected with a T. lewisi-like (Herpetosoma) species.