National Scale Real-Time Surveillance of SARS-CoV-2 Variants Dynamics by Wastewater Monitoring in Israel

In this report, we describe a national-scale monitoring of the SARS-CoV-2 (SC-2) variant dynamics in Israel, using multiple-time sampling of 13 wastewater treatment plants. We used a combination of inclusive and selective quantitative PCR assays that specifically identify variants A19/A20 or B.1.1.7 and tested each sample for the presence and relative viral RNA load of each variant. We show that between December 2020 and March 2021, a complete shift in the SC-2 variant circulation was observed, where the B.1.1.7 replaced the A19 in all examined test points. We further show that the normalized viral load (NVL) values and the average new cases per week reached a peak in January 2021 and then decreased gradually in almost all test points, in parallel with the progression of the national vaccination campaign, during February–March 2021. This study demonstrates the importance of monitoring SC-2 variant by using a combination of inclusive and selective PCR tests on a national scale through wastewater sampling, which is far more amendable for high-throughput monitoring compared with sequencing. This approach may be useful for real-time dynamics surveillance of current and future variants, such as the Omicron (BA.1, BA.2) and other variants.     

Acute gouty arthritis without urate crystals identified on initial examination of synovial fluid

Nine patients who ultimately proved to have acute gouty arthritis did not have urate crystals demonstrable by compensated polarized light in the first joint fluid aspirated despite leukocyte counts as high as 100,000/mm³. In 6 cases crystals were found in fluid from the same joint 5 hours to 1 day later. Factors that might explain the difficulty in identifying crystals include aspiration of the wrong site because diffuse swelling obscured predominant involvement of a bursa or adjacent small joint, loculation within a joint, crystal dissolution leaving only tiny birefringent chunks, and inexpert or insufficient search. Some cases remain without any tentative explanation. The possibility of acute gouty arthritis should not be excluded if crystals are not demonstrable in the first search of joint fluid. Repeated searches for typical monosodium urate crystals may be required for diagnosis.