Higher viral load and infectivity increase risk of aerosol transmission for Delta and Omicron variants of SARS-CoV-2.

Background: Airborne transmission of SARS-CoV-2 is an important route of infection. For the wildtype (WT) only a small proportion of those infected emitted large quantities of the virus. The currently prevalent variants of concern, Delta (B1.

Operational assessment of access to ART in rural Africa: the example of Kisantu in Democratic Republic of the Congo.

Despite the availability of large funds and considerable efforts to improve access to antiretroviral therapy (ART), coverage of treatment with ART remains low in Democratic Republic of the Congo (DRC). We identified the bottlenecks for adults' access to ART in a semi-rural health zone in DRC, compared ART coverage in the urban and rural area and described the outcomes and yield of different HIV testing settings. An operational model was used to examine bottlenecks in the flow of patients.

Ultrafine particle emissions from waterpipes.

Objectives: Ultrafine particle emissions from waterpipes and their impact on human health have not been extensively studied. The aim of this study was to characterise the inhalation pattern of waterpipe smokers, and (a) construct apparatus to simulate waterpipe smoking in the laboratory, and (b) characterise mainstream emissions from waterpipes under different smoking conditions.

Methods: Real life waterpipe smoking patterns were first measured with a spirometer.

Smoke-free cafe in an unregulated European city: highly welcomed and economically successful.

Objective: In a unique setting with two identical cafes, which only differed in their smoking ordinances, this study assessed the influence of smoking policies on the choice of the cafe, investigated regulatory preferences among customers, and evaluated the claim that smoking cafes have better sales performance in a city without smoking bans.

Methods: In a parallel assessment, customers of both cafes answered a questionnaire. Sales were compared and air pollutants were measured to confirm air quality differences.

Reactions of macrophages exposed to particles <10 microm.

This study describes experiments on cytotoxic effects and the production of oxidative radicals and the proinflammatory cytokine tumor growth factor alpha (TNFalpha) in a cell line of rat lung macrophages exposed to aqueous extracts from ambient air particles <10 microm (PM(10)) collected on Teflon filters. The particles were collected during the four seasons at two urban sites, one rural site, and one alpine site in Switzerland. Cytotoxic effects, determined as a reduction in the metabolic activity, were found in particle extracts from all sites and seasons.