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Understanding the transmission routes of arboviruses is key to determining their epidemiology. Here, we tested whether West Nile viruses (WNVs) are transmitted through mosquito excreta. First, we observed a high concentration of infectious units per excreta, although viruses were short lived. Second, we showed that virion excretion starts early after oral infection and remains constant for a long period, regardless of mosquito infection level. These results highlight the infectiousness of excreta from infected mosquitoes. Third, we found that both larvae and pupae were susceptible to infection, while pupae were highly permissive. Fourth, we established the proof-of-concept that immature mosquitoes can be infected by infectious excreta, demonstrating an excreta-mediated mode of transmission. Finally, by mathematically modeling excreta-mediated transmission in the field, we demonstrated that WNV can be transmitted within mosquito populations. Our study uncovers a route of transmission for mosquito-borne arboviruses, unveiling mechanisms of viral maintenance in mosquito reservoirs., Competing Interests: The authors declare no competing interests., (© 2024 The Author(s). Published by Elsevier Inc.)

Unlabelled: Arthroscopic arthrolysis is a reliable technique for the treatment of knee stiffness due to arthrofibrosis following ligament replacement or following the treatment of knee fracture. However, its use is uncommon for this indication in total knee arthroplasty (TKA). In this study, we questioned whether or not arthroscopy is a reliable technique for treatment of knee stiffness following TKA, due to arthrofibrosis., Materials and Methods: Four men mean aged 54 (38-70) underwent knee arthroscopy for a history of arthrofibrosis following TKA. In two cases the arthrofibrosis had appeared after a primary TKA done for limited range of motion and in two other cases had followed a revision arthroplasty. The mean knee flexion before the TKA was 80 degrees (40-110) and it was 105 degrees (100-120) after performing the TKA. The knees were not mobilized under anesthesia though the mean flexion was 75 degrees (60-80) 15 days after the TKA. The indication for arthroscopy was a painless limited range of motion of the knee. The arthroscopy was performed 6 months (2.5-12) after the TKA and at this time the flexion was limited to 65 degrees (60-80). The extension was limited in 2 cases to 10 degrees and 30 degrees. Patients were evaluated an average of 20 months (8-36) after the arthroscopy. With 2 peripatellar portals we sectioned the adhesions in the suprapatellar pouch, the 2 retinaculars and the adhesive bands in the 2 gutters. Two anterior additional portals were used in case of extension lag. A suction drain was placed and the portals were sutured. A continuous passive motion machine was started in the recovery room., Results: The mean operating time for arthroscopic arthrolysis was 38 minutes (30-60). The mean knee flexion was 116 degrees (100-130) at the end of arthroscopy and was 93 degrees (75-110) at the last review. The mean flexion improved by 31 degrees (15-50). The mean flexion improved by 45% (25-83). The 2 extension lags decreased respectively from 30 degrees to 10 degrees and from 10 degrees to 0 degree. For these 2 patients the increase in range of motion was 70 degrees and 40 degrees respectively. The average amount of bleeding was 200 ml (86-520). There were no complications., Discussion: Few surgeons are experienced in arthroscopy for knee stiffness after TKA. Our results are similar to those reported by most authors. Regarding the technique, the section of the two retinaculars is necessary for the mobility of the patellar and most of the mobility is gained after the release of the gutters. The use of only two portals avoids damaging the TKA component and decreases the theoretical risk of infection. The major loss of motion after arthrolysis occurred during the first days following the arthroscopy. This is why we recommend using a regional anesthesia for the arthroscopy and during the following days to allow intensive mobilization of the knee. The arthrolysis should be done from 3 to 6 months after the TKA for better results., Conclusion: Arthroscopy for the treatment of knee stiffness, due to arthrofibrosis, following TKA is a useful, reliable and safe technique.