Sexual Distancing During 5 Periods Around and During the COVID-19 Pandemic, Amsterdam, the Netherlands.

BACKGROUND: Social and sexual distancing (ie, abstaining from sex with persons outside one's household) was important in the control of the COVID-19 pandemic. Compliance to distancing measures can change over time. We assessed changes in compliance to the sexual distancing measures during five periods of the COVID-19 pandemic in the Netherlands. METHODS: Between November 2021 and March 2022, we used a structured questionnaire containing questions about sexual behavior and factors that could have influenced compliance with sexual distancing. Variables related to sexual behavior were measured for 5 periods, before and during the pandemic, delineated by imposement and relaxation of lockdown measures. RESULTS: Eight hundred seventy participants (predominantly MSM) completed the questionnaire. We found that compliance to the sexual distancing measures decreased over time. The number of casual partners was highest after the lockdown measures were relaxed for the second time (April 2021 to March 2022), and even higher than before the first lockdown. Factors positively associated with sexual distancing compliance were: having confidence in the information provided by the government and experiencing less or similar need for physical contact compared with before the pandemic. Factors that lowered compliance over time were: previously having had COVID-19, perceiving the lockdown measures as overstated, having sex with casual partners and similar drug use during the pandemic as before. CONCLUSIONS: Our findings suggest that sexual distancing measures are difficult to maintain for a long period. Other measures, such as confinement to a small network of known partners, might be more effective for longer pandemics in minimizing the spread of infectious diseases.

Barriers and Motives for Complying With "Sexual Distancing" Among Men Who Have Sex With Men During the First COVID-19 Pandemic Lockdown in Amsterdam: A Qualitative Study.

BACKGROUND: Between March 15 and May 31, 2020, the Dutch government imposed lockdown and health measures to curb the coronavirus disease 2019 (COVID-19) pandemic. As part of social distancing, sexual distancing was one of these measures. Sexual distancing implied refraining from sex with partners outside of one's household. We aimed to elucidate barriers and motives for complying with sexual distancing and related factors that could have led to (non)compliance among men who have sex with men. METHODS: In this exploratory qualitative study, we interviewed men who have sex with men who visited the center for sexual health in Amsterdam during the first COVID-19 lockdown using a semistructured interview guide from March to May 2020. We interviewed both men who complied and did not comply with sexual distancing. The interviews were transcribed verbatim and analyzed using an open-coding process in MAXQDA. RESULTS: We included 18 noncompliers and 4 compliers to COVID-19 sexual distancing. Barriers to compliance were the following: lack of information on, or understanding of, the need for sexual distancing; being single; having had an active sex life before COVID-19; a high perceived importance of the social aspect of sex; a strong urge for sex; using sex to cope with the negative impact of the pandemic; being under the influence of alcohol or drugs; and not perceiving COVID-19 as a serious health threat. Motives for compliance were the following: perceiving COVID-19 as a serious health threat, direct confrontation with critically ill COVID-19 patients, protecting someone dear from COVID-19, and being convinced of the importance of social and/or sexual distancing measures. CONCLUSIONS: Information on sexual distancing needs to be made more explicit, accessible, understandable, inclusive, customized to individual barriers, and relatable to the key populations. This may improve the effectiveness of measures and health recommendations in both the current COVID-19 pandemic and future respiratory outbreaks.

Structure and mechanism of a cysteine sulfinate desulfinase engineered on the aspartate aminotransferase scaffold.

The joint substitution of three active-site residues in Escherichia coli (L)-aspartate aminotransferase increases the ratio of l-cysteine sulfinate desulfinase to transaminase activity 10(5)-fold. This change in reaction specificity results from combining a tyrosine-shift double mutation (Y214Q/R280Y) with a non-conservative substitution of a substrate-binding residue (I33Q). Tyr214 hydrogen bonds with O3 of the cofactor and is close to Arg374 which binds the α-carboxylate group of the substrate; Arg280 interacts with the distal carboxylate group of the substrate; and Ile33 is part of the hydrophobic patch near the entrance to the active site, presumably participating in the domain closure essential for the transamination reaction. In the triple-mutant enzyme, k(cat)' for desulfination of l-cysteine sulfinate increased to 0.5s(-1) (from 0.05s(-1) in wild-type enzyme), whereas k(cat)' for transamination of the same substrate was reduced from 510s(-1) to 0.05s(-1). Similarly, k(cat)' for ß-decarboxylation of l-aspartate increased from<0.0001s(-1) to 0.07s(-1), whereas k(cat)' for transamination was reduced from 530s(-1) to 0.13s(-1). l-Aspartate aminotransferase had thus been converted into an l-cysteine sulfinate desulfinase that catalyzes transamination and l-aspartate ß-decarboxylation as side reactions. The X-ray structures of the engineered l-cysteine sulfinate desulfinase in its pyridoxal-5'-phosphate and pyridoxamine-5'-phosphate form or liganded with a covalent coenzyme-substrate adduct identified the subtle structural changes that suffice for generating desulfinase activity and concomitantly abolishing transaminase activity toward dicarboxylic amino acids. Apparently, the triple mutation impairs the domain closure thus favoring reprotonation of alternative acceptor sites in coenzyme-substrate intermediates by bulk water.