Résumé
Even if the number of Human African Trypanosomiasis (HAT) cases from Kinshasa province in DRC is going towards elimination for the last decade, cases still occur in the periphery of the city. The diagnosis of 21 cases in the south periphery of Kinshasa, between 2015 and 2017 gives evidence of the existence of an active focus in this area.
Here, we present the results of a punctual entomological survey that was realized in july 2014 in the outskirts of the southeast of Kinshasa. Using pyramidal traps, we caught tsetse flies during 2 days, dissecting the fresh ones for further molecular analysis. The average Apparent Density of flies per Trap and per Day was three with a maximum of 5.6 flies in Nganda PIO. Polymerase chain reaction analysis of the midguts provided evidence of a high prevalence (57.2%) of infected flies. Ninety three percent of the trypanosomes that were identified belonged to the Nanomonas species, but Trypanozoon trypanosomes were also present in 24% of the infected flies, including mixed infections with Nanomonas, including 3 flies carrying Trypanosoma brucei gambiense, the human pathogen of trypanosomiasis.
These results show that at the time of the field's study there was an active reservoir of trypanosomes, closed to pigsties, knowing that pig is a potential animal reservoir. It also demonstrates that xenomonitoring using the entomological approach can be an efficient tool for monitoring sleeping sickness. Finally, results are discussed in the frame of WHO's HAT elimination project. Regarding Kinshasa, it points out the need of regular epidemiologic surveys.
•Despite trypanosomiasis is decreasing, number of HAT and AAT foci are still active.•In outskirts of Kinshasa City (DRC), more than 57% of tsetse flies host the parasite.•Most flies were infected with T. congolense (≥ AAT), some with T.b. gambiense (≥ HAT).•Pigs from the pigsties present in the foci are most probably trypanosome reservoirs.•Results show molecular xenomonitoring to be efficient for monitoring sleeping sickness.