[The cases of tracing the source of patients infected with Omicron variant of SARS-CoV-2 based on wastewater-based epidemiology in Shenzhen].

Wastewater-based epidemiology (WBE) is an emerging discipline, which has been applied to drug abuse tracking and infectious disease pathogen surveillance. During the COVID-19 epidemic, WBE has been applied to monitor the epidemic trend and SARS-CoV-2 variants etc. In order to detect hidden COVID-19 cases and prevent transmission in the community, wastewater surveillance system for monitoring SARS-CoV-2 RNA was developed in Shenzhen. The sewage sampling sites were set up in key places such as the port areas, urban villages and residential communities of Futian, Nanshan, Luohu and Yantian districts. From July 26 to November 30, 2022, a total of 369 sewage sampling sites were set up, covering 1.93 million people. Continuous sampling was carried out for 3 hours in the peak period of water use every day. Sewage virus enrichment and SARS-CoV-2 nucleic acid detection were carried out by polyethylene glycol precipitation method and RT-qPCR, and a positive water sample disposal process was molded. This article aims to introduce the case of source tracing of COVID-19 infected patients based on urban sewage in Shenzhen. The sewage monitoring of Honghu water treatment plant in Luohu District played an early warning role, and the source of infection was traced. In the disposal of positive water samples in Futian South Road, Futian District, the important experience of monitoring point layout was obtained. In the sewage monitoring of Nanshan village, Nanshan District, the existence of occult infection was revealed. Sharing the experience of tracing the source of COVID-19 patients to avoid the spread of COVID-19 in the community based on wastewater surveillance of SARS-CoV-2 RNA in Shenzhen, and summarizing the advantages and application prospects of sewage surveillance can provide new ideas for monitoring emerging or re-emerging pathogens that are known to exhibit gastrointestinal excretion in the future.

[Bilateral acute regional occult outer retinopathy: a case report].

A 63-year-old female patient presented with "flashes of light in both eyes accompanied by decreased visual acuity for one year." Visual field examination revealed partial defects in the central 30° of the visual field in both eyes. Scanning laser ophthalmoscopy showed extensive atrophic lesions across the entire posterior pole of the retina in both eyes. Optical coherence tomography revealed atrophy and thinning of the retina in the macular regions, with significant atrophy of the photoreceptor inner segment and outer segment layer in the areas corresponding to the visual field defects. Fluorescein fundus angiography demonstrated thinning of the retinal arterioles. Early-phase imaging showed large window-like defects in the posterior retina with background fluorescence from choroidal macrovessels. In the late phase, patchy fluorescence staining with a circumferential hyperfluorescent area was observed. Pattern visual evoked potential and pattern electroretinography tests revealed a significant decrease in the P100 amplitude in both eyes. The patient was diagnosed with acute regional occult outer layer retinopathy in both eyes.