Have tsetse flies disappeared from Brazzaville town?

BACKGROUND: From 1980 to 1985, the zoological park of Brazzaville was the only tsetse resting site located in downtown which supplied others temporary sites. The last trapping survey carried out in this area in 1987 showed that there were no more tsetse flies. Knowing that areas free of tsetse used to be reinvaded many years later, we have carried out an entomological survey in the area with the aim to verify what has happened more than twenty years later; given that suitable environmental conditions for Glossina are still available. METHODS: Sixteen pyramidal traps were set out at the edge of the forest, along paths and around animal’s cages and were examined twice a day, at 10 a.m. and 4 p.m. during four days. RESULTS: No tsetse fly was captured. Using the formula previously described; the probability of capturing a tsetse fly is 0.002. CONCLUSION: The zoological park seems close to be free of tsetse flies. Long-lasting surveys within the town and around are required before stating a complete disappearance of tsetse in the town.