Infectious viral load in unvaccinated and vaccinated patients infected with SARS-CoV-2 WT, Delta and Omicron

Background Viral load (VL) is one determinant of secondary transmission of SARS-CoV-2. Emergence of variants of concerns (VOC) Alpha and Delta was ascribed, at least partly, to higher VL. Furthermore, with parts of the population vaccinated, knowledge on VL in vaccine breakthrough infections is crucial. As RNA VL is only a weak proxy for infectiousness, studies on infectious virus presence by cell culture isolation are of importance. Methods We assessed nasopharyngeal swabs of COVID-19 patients for quantitative infectious viral titres (IVT) by focus-forming assay and compared to overall virus isolation success and RNA genome copies. We assessed infectious viral titres during the first 5 symptomatic days in a total of 384 patients: unvaccinated individuals infected with pre-VOC SARS-CoV-2 (n= 118) or Delta (n= 127) and vaccine breakthrough infections with Delta (n= 121) or Omicron (n=18). Findings Correlation between RNA copy number and IVT was low for all groups. No correlation between IVTs and age or sex was seen. We observed higher RNA genome copies in pre-VOC SARS-CoV-2 compared to Delta, but significantly higher IVTs in Delta infected individuals. In vaccinated vs. unvaccinated Delta infected individuals, RNA genome copies were comparable but vaccinated individuals have significantly lower IVTs, and cleared virus faster. Vaccinated individuals with Omicron infection had comparable IVTs to Delta breakthrough infections. Interpretation Quantitative IVTs can give detailed insights into virus shedding kinetics. Vaccination was associated with lower infectious titres and faster clearance for Delta, showing that vaccination would also lower transmission risk. Omicron vaccine breakthrough infections did not show elevated IVTs compared to Delta, suggesting that other mechanisms than increase VL contribute to the high infectiousness of Omicron. Funding This work was supported by the Swiss National Science Foundation 196644, 196383, NRP (National Research Program) 78 Covid-19 Grant 198412, the Fondation Ancrage Bienfaisance du Groupe Pictet and the Fondation Privée des Hôpitaux Universitaires de Genève.

Mapping environmental suitability of Haemagogus and Sabethes spp. mosquitoes to understand sylvatic transmission risk of yellow fever virus in Brazil

Background Yellow fever (YF) is an arboviral disease which is endemic to Brazil due to a sylvatic transmission cycle maintained by infected mosquito vectors, non-human primate (NHP) hosts, and humans. Despite the existence of an effective vaccine, recent sporadic YF epidemics have underscored concerns about sylvatic vector surveillance, as very little is known about their spatial distribution. Here, we model and map the environmental suitability of YF’s main vectors in Brazil, Haemagogus spp. and Sabethes spp., and use human population and NHP data to identify locations prone to transmission and spillover risk. Methodology/Principal findings We compiled a comprehensive set of occurrence records on Hg. janthinomys, Hg. leucocelaenus, and Sabethes spp. from 1991–2019 using primary and secondary data sources. Linking these data with selected environmental and land-cover variables, we adopted a stacked regression ensemble modelling approach (elastic-net regularized GLM, extreme gradient boosted regression trees, and random forest) to predict the environmental suitability of these species across Brazil at a 1x1 km resolution. We show that while suitability for each species varies spatially, high suitability for all species was predicted in the Southeastern region where recent outbreaks have occurred. By integrating data on NHP host reservoirs and human populations, our risk maps further highlight municipalities within the region that are prone to transmission and spillover. Conclusions/Significance Our maps of sylvatic vector suitability can help elucidate potential locations of sylvatic reservoirs and be used as a tool to help mitigate risk of future YF outbreaks and assist in vector surveillance. Furthermore, at-risk regions identified from our work could help disease control and elucidate gaps in vaccination coverage and NHP host surveillance.

Rapid evidence review to inform safe return to campus in the context of coronavirus disease 2019 (COVID-19)

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted predominantly through the air in crowded and unventilated indoor spaces, especially among unvaccinated people. Universities and colleges are potential settings for its spread. Methods: An interdisciplinary team from public health, virology, and biology used narrative methods to summarise and synthesise evidence on key control measures, taking account of mode of transmission. Results: Evidence from a wide range of primary studies supports six measures. Vaccinate (aim for > 90% coverage and make it easy to get a jab). Require masks indoors, especially in crowded settings. If everyone wears well-fitting cloth masks, source control will be high, but for maximum self-protection, respirator masks should be worn. Masks should not be removed for speaking or singing. Space people out by physical distancing (but there is no “safe” distance because transmission risk varies with factors such as ventilation, activity levels and crowding), reducing class size (including offering blended learning), and cohorting (students remain in small groups with no cross-mixing). Clean indoor air using engineering controls—ventilation (while monitoring CO2 levels), inbuilt filtration systems, or portable air cleaners fitted with high efficiency particulate air [HEPA] filters). Test asymptomatic staff and students using lateral flow tests, with tracing and isolating infectious cases when incidence of coronavirus disease 2019 (COVID-19) is high. Support clinically vulnerable people to work remotely. There is no direct evidence to support hand sanitising, fomite controls or temperature-taking. There was no evidence that freestanding plastic screens, face visors and electronic air-cleaning systems are effective. Conclusions: The above evidence-based measures should be combined into a multi-faceted strategy to maximise both student safety and the continuation of in-person and online education provision. Those seeking to provide a safe working and learning environment should collect data (e.g. CO2 levels, room occupancy) to inform their efforts.

Aedes aegypti abundance, larval indices and risk for dengue virus transmission in Kinondoni district, Tanzania

Background Tanzania has experienced periodic dengue outbreaks with increased incidence since 2010. However, there is limited information on vector dynamics and transmission risk in most parts of the country. This study was conducted to determine Aedes mosquito abundance, larval indices and dengue virus infection rate as risk indicators for DENV transmission in Kinondoni district, Dar es Salaam, Tanzania. Methods A cross-sectional study was conducted in three wards of Kinondoni district in Tanzania between December 2019 and January 2020. In each ward, three streets were randomly selected for adult and immature mosquito sampling. The adult mosquitoes were collected using Mosquito Magnet traps, while mosquito larvae and pupae were inspected in water-holding containers in the selected household compounds. The detection of dengue virus (DENV) in female Aedes mosquitoes was done using a one-step reverse transcription–polymerase chain reaction (RT–PCR) method. Results Of the 1416 adult female mosquitoes collected, Ae. aegypti accounted for 16.8% (n = 238). A total of 333 water-holding containers were inspected and 201 (60.4%) had at least an Aedes larvae or pupae. Water-holding containers supporting the breeding of Aedes larvae and pupae included discarded car tires, flowerpots and small and large plastic containers. The overall House Index, Container Index and Breteau Index were 55.1%, 60.4% and 114.2, respectively. None of the 763 female Aedes mosquitoes tested by RT–PCR was found to be infected with DENV. Conclusion The presence and abundance Ae. aegypti mosquitoes and the large proportion of water-holding containers infested with the mosquito larvae and pupae put residents of Kinondoni district at high risk of DENV transmission. Our findings emphasize the need for continuous mosquito vector surveillance and control to prevent the possibility of future DENV outbreaks in Tanzania.

Rapidly Progressive Pituitary Apoplexy in a Patient with COVID-19 Disease Treated with Endoscopic Endonasal Surgery

This report describes a case of pituitary apoplexy with rapidly evolving hemorrhage in a 74-year-old female with coronavirus disease 2019 (COVID-19) disease. The patient presented with severe headache and mild respiratory symptoms, with laboratories concerning for pituitary hypofunction. Brain imaging demonstrated a sellar mass concerning for a pituitary adenoma with ischemic apoplexy. She subsequently developed visual deficits within 24 hours of presentation, and repeat imaging demonstrated evolving hemorrhage and new mass effect on the optic chiasm. She was successfully managed with urgent endoscopic endonasal surgery despite her COVID-19 positive status by taking special intraoperative precautions to mitigate SARS-CoV2 transmission risk. Only a handful of cases of pituitary apoplexy have been reported in association with COVID-19 disease, and even fewer reports exist of endonasal procedures in such cases. We discuss the potential implication of COVID-19 in the occurrence of pituitary apoplexy, in addition to the safety and success of endonasal surgery in this population.

Multidrug-Resistant Bacteria on Healthcare Workers’ Uniforms in Hospitals and Long-Term Care Facilities in Cyprus

Healthcare workers’ (HCW) clothing has been shown to harbor multidrug-resistant bacteria (MDRB) and may contribute to transmission. The aim of this study was to evaluate presence of MDRB on HCW uniforms in Cyprus. A cross-sectional study was carried out in 9 hospital wards and 7 long-term care facilities (LTCFs) in Nicosia, Cyprus, from April–August 2019. Sampling of HCW uniform pockets was conducted at the end of the first shift. Personal hygiene and other habits were recorded during personal interviews. Among 140 sampled HCW (69 from hospitals, 71 from LTCFs), 37 MDRB were identified, including 16 vancomycin-resistant enterococci (VRE), 15 methicillin-resistant Staphylococcus aureus (MRSA), 5 extended spectrum b-lactamase (ESBL)-producing bacteria, and 1 carbapenem-resistant Acinetobacter baumannii. Presence of MDRB was higher in LTCFs compared to hospitals (p = 0.03). Higher MDRB rates in uniforms were noted in HCWs that worked <1 year (41.7% vs. 21.1%) and in HCWs that opted for home laundering (23.5% vs. 12.5%) or visited the toilet during shifts (38.1% vs. 20.2%). Our findings indicate that HCW uniforms harbor MDRB and relevant interventions may reduce transmission risk. We identified LTCFs as an important area for targeted measures. Additional factors associated with HCW practices, characteristics, and attire laundering practices represent areas for improvement, particularly in LTCFs.

Years Since Diagnosis Among People Living With Diagnosed HIV in New York City

Antiretroviral treatment has greatly improved the survival of people living with diagnosed HIV (PLWDH), but little information is available on the time since diagnosis among them. Using New York City HIV surveillance data, we described the trend in the number of years since diagnosis among PLWDH during 2010-2019 and reported the mean, median, and interquartile range (IQR) of years since diagnosis among PLWDH in New York City in 2019, overall and by gender, race and ethnicity, and transmission risk. The median number of years since diagnosis among PLWDH in New York City increased from 10.5 years (IQR, 6.3-15.6) in 2010 to 16.3 years (IQR, 8.9-22.1) in 2019. By gender, transgender people had the shortest time since diagnosis, with a median of 11.4 years (IQR, 5.6-17.9), compared with men (median = 15.2 years; IQR, 8.1-21.6) and women (median, 18.5 years; IQR, 12.0-23.0). By race and ethnicity, non-Hispanic White people had been living with the diagnosis for the longest time (median = 17.4 years; IQR, 9.5-23.5), and Asian/Pacific Islander people had been living with the diagnosis for the shortest time (median = 10.1 years; IQR, 4.7-17.0). With an expected and continuing increase in the number of years since HIV diagnosis among PLWDH, programs that provide treatment and support services will need to be expanded, updated, and improved.