Phylogeography of horseshoe bat sarbecoviruses in Vietnam and neighbouring countries. Implications for the origins of SARS-CoV and SARS-CoV-2.

Previous studies on horseshoe bats (Rhinolophus spp.) have described many coronaviruses related to SARS-CoV (SARSCoVr) in China and only a few coronaviruses related to SARS-CoV-2 (SARSCoV2r) in Yunnan (southern China), Cambodia, Laos and Thailand. Here, we report the results of several field missions carried out in 2017, 2021 and 2022 across Vietnam during which 1218 horseshoe bats were sampled from 19 locations. Sarbecoviruses were detected in 11% of faecal RNA extracts, with much more positives among Rhinolophus thomasi (46%). We assembled 38 Sarbecovirus genomes, including 32 SARSCoVr, four SARSCoV2r, and two recombinants of SARSCoVr and SARSCoV2r (RecSar), one showing a Spike protein very similar to SARS-CoV-2. We detected a bat co-infected with four coronaviruses, including two sarbecoviruses. Our analyses revealed that Sarbecovirus genomes evolve in Vietnam under strong geographical and host constraints. First, we found evidence for a deep separation between viruses from northern Vietnam and those from central and southern Vietnam. Second, we detected only SARSCoVr in Rhinolophus thomasi, both SARSCoVr and SARSCoV2r in Rhinolophus affinis, and only RecSar in Rhinolophus pusillus captured close to the border with China. Third, the bias in favour of Uracil in synonymous third codon positions of SARSCoVr extracted from R. thomasi showed a negative correlation with latitudes. Our results also provided support for an emergence of SARS-CoV in horseshoe bats from northern Yunnan and emergence of SARS-CoV-2 in horseshoe bats from northern Indochina subtropical forests (southern Yunnan, northern Laos and north-western Vietnam).

Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia.

PURPOSE: The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis. METHODS: A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency. RESULTS: The preoperative manifest refraction spherical equivalent was -7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (P < 0.05). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (P < 0.05). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (P < 0.05). CONCLUSION: Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.