The use of molecular technology to investigate trypanosome infections in tsetse flies at Liwonde Wild Life Reserve.

BACKGROUND

Trypanosomes are protozoan flagellates that cause human African trypanosomiasis (HAT) and African animal trypanosomiasis (AAT). HAT is caused by e in East and Central Africa and in West Africa, whereas AAT is caused by a number of trypanosome species, including and The aim of this study was to establish if tsetse flies at Liwonde Wild Life Reserve (LWLR) are infected with these trypanosomes and thus pose a risk to both humans and animals within and surrounding the LWLR.

METHODS

A total of 150 tsetse flies were caught. Of these, 82 remained alive after capture and were dissected such that the mid-gut could be examined microscopically for trypanosomes. DNA extractions were performed from both mid-guts and the 68 dead flies using a Qiagen Kit. Amplification techniques involved the Internal Transcriber Spacer 1 (ITS 1) conventional polymerase chain reaction (PCR) with primers designed to identify trypanosome species, and Repetitive Insertion Mobile Element - Loop Mediated Isothermal Amplification (RIME LAMP), a sequence specific to T. brucei.

RESULTS

Analysis showed that 79/82 (96.3%) of the mid-guts examined microscopically were positive for trypanosomes and that 75/150 (50%) of the DNA extracts (from the mid-gut, and tsetse fly carcasses) were positive for T. brucei, as determined by the RIME LAMP method. ITS1 PCR further showed that 87/150 (58.0%) flies were positive for trypanosomes, of which 56/87 (64.4%) were 9/87 (10.3%) were 7/87 (8.1%) were ; 6/87 (6.9%) were and 6/87 (6.9%) were Ten samples had a mixture of infections.

CONCLUSION

Our analysis demonstrated a mixture of infections from trypanosome species in tsetse flies at LWLR, and that the species that causes HAT, was the most common. Our study successfully used molecular techniques to demonstrate the presence of at LWLR, a species that causes HAT in both East and Central Africa.