The global burden of trichiasis in 2016.

BACKGROUND: Trichiasis is present when one or more eyelashes touches the eye. Uncorrected, it can cause blindness. Accurate estimates of numbers affected, and their geographical distribution, help guide resource allocation. METHODS: We obtained district-level trichiasis prevalence estimates in adults for 44 endemic and previously-endemic countries. We used (1) the most recent data for a district, if more than one estimate was available; (2) age- and sex-standardized corrections of historic estimates, where raw data were available; (3) historic estimates adjusted using a mean adjustment factor for districts where raw data were unavailable; and (4) expert assessment of available data for districts for which no prevalence estimates were available. FINDINGS: Internally age- and sex-standardized data represented 1,355 districts and contributed 662 thousand cases (95% confidence interval [CI] 324 thousand-1.1 million) to the global total. Age- and sex-standardized district-level prevalence estimates differed from raw estimates by a mean factor of 0.45 (range 0.03-2.28). Previously non- stratified estimates for 398 districts, adjusted by ×0.45, contributed a further 411 thousand cases (95% CI 283-557 thousand). Eight countries retained previous estimates, contributing 848 thousand cases (95% CI 225 thousand-1.7 million). New expert assessments in 14 countries contributed 862 thousand cases (95% CI 228 thousand-1.7 million). The global trichiasis burden in 2016 was 2.8 million cases (95% CI 1.1-5.2 million). INTERPRETATION: The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence

Evaluation of the ability of indigenous nematode isolates of Heterorhabditis taysearae and Steinernema kandii to control mango fruit fly Bactrocera dorsalis under laboratory, semi-field and field conditions in Northern Benin

We investigated the use of entomopathogenic nematodes to biologically control Bactrocera dorsalis in mango orchards. One isolate of Steinernema kandii (Thui) and two of Heterorhabditis taysearae (Hessa1 and Korobororou F4) were studied for their invasion time and virulence to third instar larvae of B. dorsalis in laboratory and semi field tests, respectively. In addition, the persistence of the same nematode isolates in soil under field conditions was tested. Results showed that all three nematode isolates could penetrate insect larvae after 2 h of exposure time. Furthermore, under semi field conditions, insect mortality was significantly different among EPN application times. The three nematode isolates were highly pathogenic to B. dorsalis with H. taysearae Hessa1 being the most virulent (70.84% +/- 10.46 [SEM] mortality) when EPNs were applied three days before insect introduction in the experimental pots. Moreover, Steinernema kandii persisted in soil up to 32 weeks after nematode application whereas both H. taysearae isolates persisted 30 weeks post application in the mango orchard. In general, four weeks upon nematode application, the density of infective juveniles decreased considerably and remained variable the following sampling dates