Abstract:

Objective To diagnose an imported case of suspected African trypanosomiasis by laboratory tools. Methods Clinical information of the patient was collected. The blood and cerebrospinal fluid samples were examined by microscopy after Giemsa staining. DNA of Trypanosoma brucei was extracted from the patient blood sample, and amplified by PCR using primers for T. brucei genus expression site-associated gene(ESAG), T. brucei gambiense-specific glycoprotein(TgsGP) and T. brucei rhodesiense serum resistance-associated (SRA) gene. The PCR products underwent electrophoresis, sequencing, and the sequences were blasted in GenBank. Results The patient was a 41-year-old female from Fuzhou, Fujian Province. She was bitten by an unknown insect in Serengeti National Park of Tanzania (July 28-29, 2018). After returning to China on August 6, she began to develop symptoms of fever, fatigue, and coughing on August 8. She visited a class A hospital in Fuzhou City, where he was disgnosed with infectious fever. The symptoms were not improved after treatment with efdinir (for anti-infection) and Saridon (for fever). The patient was transferred to another class A hospital in the city on August 9, but the fever was still not effectively ameliorated after a combination of anti-infective eftizoxime, anti-viral Tamiflu, phlegm-resolving Mucosolvin and Shiwei Longdanhua Capsule, liver-protective Tianxing and diisopropylamine chloroacetate, and nutrition support, accompanied by progressive increases of liver enzymes. On August 14, the blood and cerebrospinal fluid samples of the patient were sent to Fujian Provincial Center for Disease Control and Prevention for Plasmodium examination. Microscopy of the Giemsa-stained samples showed suspected African trypanosome trypomastigotes in the blood sample, but failed to find Plasmodium. No Trypanosoma was found in the cerebrospinal fluid. PCR results showed a product of 260 bp with the primers for ESAG, no specific product with the primers for TgsGP but a product of 266 bp with the primers for SRA. Results of sequence alignment revealed that the EASG amplified sequence had a 95% homology with AY682003.1, and the SRA amplified sequence had a 99% homology with AJ345058.1. After confirmation of T. brucei rhodesiense infection, the patient was intravenously injected with 20 mg/kg suramin (provided by WHO) on days 1, 3, 7, 14 and 21, with dosage no more than 1 g at each injection. After one treatment course, the patient basically recovered, and was not detected with Trypanosoma at regular checkups in the hospital. Conclusion The case is confirmed to be T. brucei rhodesiense infection by the laboratory diagnosis.

Key words: Rhodesiense, African trypanosomiasis, Imported, Diagnosis