Spatio-temporal survey of small mammal-borne Trypanosoma lewisi in Cotonou, Benin, and the potential risk of human infection.

Human trypanosomoses are the sleeping sickness in Africa and Chagas disease in Latin America. However, atypical human infections by animal trypanosomes have been described, but poorly investigated. Among them, the supposed rat-specific T. lewisi was shown to be responsible for a few severe cases. In Africa, the scarcity of data and the null awareness about the atypical human trypanosomoses suggest that the number of cases may be higher that currently thought. Furthermore, T. lewisi is resistant to normal human serum and therefore a potential human pathogen. In order to document T. lewisi distribution and ecology, a qPCR- and 16DNA sequencing-based survey was conducted in 369 rodents from three urban districts of Cotonou city, Benin, during three different periods of the same year. Our study demonstrated very high prevalence (57.2%) even when considering only individuals identified as positive through DNA sequencing (39.2%). Black rats represented the most dominant as well as the most T. lewisi-parasitized species. No difference was retrieved neither between seasons nor districts, suggesting a large infestation of rodents by trypanosomes throughout the year and the city. Our results suggest that conditions are gathered for rat to human transmission of T. lewisi in these socio-environmentally degraded urban areas, thus pointing towards the rapidly urbanizing Abidjan-Lagos corridor as a region at particular risk.

Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus.

PURPOSE: Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus were measured to study the release of telopeptides in the tears. METHODS: Tear samples were collected from 26 keratoconus patients and 36 age-similar human control subjects. Levels of telopeptides were quantified and compared between the two groups. RESULTS: The telopeptide level in tears from keratoconus patients was 2.5-fold higher than in tears from the control group. The telopeptide concentration was age-dependent in both groups. In tears from young people, telopeptide level was 2-fold higher than in tears from the older people. CONCLUSION: The tear film of patients with keratoconus contains higher levels of telopeptides than those of control subjects. Determination of telopeptide levels in tears could be useful for the follow-up of keratoconus development in patients.