Transmission of COVID-19 and other infectious diseases in public washrooms: A systematic review

Reduction of acute respiratory infections in day-care by non-pharmaceutical interventions: a narrative review

Objective

Children who start in day-care have 2-4 times as many respiratory infections compared to children who are cared for at home, and day-care staff are among the employees with the highest absenteeism. The extensive new knowledge that has been generated in the COVID-19 era should be used in the prevention measures we prioritize. The purpose of this narrative review is to answer the questions: Which respiratory viruses are the most significant in day-care centers and similar indoor environments? What do we know about the transmission route of these viruses? What evidence is there for the effectiveness of different non-pharmaceutical prevention measures?

Design

Literature searches with different terms related to respiratory infections in humans, mitigation strategies, viral transmission mechanisms, and with special focus on day-care, kindergarten or child nurseries, were conducted in PubMed database and Web of Science. Searches with each of the main viruses in combination with transmission, infectivity, and infectious spread were conducted separately supplemented through the references of articles that were retrieved.

Results

Five viruses were found to be responsible for ≈95% of respiratory infections: rhinovirus, (RV), influenza virus (IV), respiratory syncytial virus (RSV), coronavirus (CoV), and adenovirus (AdV). Novel research, emerged during the COVID-19 pandemic, suggests that most respiratory viruses are primarily transmitted in an airborne manner carried by aerosols (microdroplets).

Conclusion

Since airborne transmission is dominant for the most common respiratory viruses, the most important preventive measures consist of better indoor air quality that reduces viral concentrations and viability by appropriate ventilation strategies. Furthermore, control of the relative humidity and temperature, which ensures optimal respiratory functionality and, together with low resident density (or mask use) and increased time outdoors, can reduce the occurrence of respiratory infections.

Pathogen Discovery in the Post-COVID Era

Pathogen discovery plays a crucial role in the fields of infectious diseases, clinical microbiology, and public health. During the past four years, the global response to the COVID-19 pandemic highlighted the importance of early and accurate identification of novel pathogens for effective management and prevention of outbreaks. The post-COVID era has ushered in a new phase of infectious disease research, marked by accelerated advancements in pathogen discovery. This review encapsulates the recent innovations and paradigm shifts that have reshaped the landscape of pathogen discovery in response to the COVID-19 pandemic. Primarily, we summarize the latest technology innovations, applications, and causation proving strategies that enable rapid and accurate pathogen discovery for both acute and historical infections. We also explored the significance and the latest trends and approaches being employed for effective implementation of pathogen discovery from various clinical and environmental samples. Furthermore, we emphasize the collaborative nature of the pandemic response, which has led to the establishment of global networks for pathogen discovery.

Environmental dissemination of respiratory viruses: dynamic interdependencies of respiratory droplets, aerosols, aerial particulates, environmental surfaces, and contribution of viral re-aerosolization

During the recent pandemic of COVID-19 (SARS-CoV-2), influential public health agencies such as the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) have favored the view that SARS CoV-2 spreads predominantly via droplets. Many experts in aerobiology have openly opposed that stance, forcing a vigorous debate on the topic. In this review, we discuss the various proposed modes of viral transmission, stressing the interdependencies between droplet, aerosol, and fomite spread. Relative humidity and temperature prevailing determine the rates at which respiratory aerosols and droplets emitted from an expiratory event (sneezing, coughing, etc.) evaporate to form smaller droplets or aerosols, or experience hygroscopic growth. Gravitational settling of droplets may result in contamination of environmental surfaces (fomites). Depending upon human, animal and mechanical activities in the occupied space indoors, viruses deposited on environmental surfaces may be re-aerosolized (re-suspended) to contribute to aerosols, and can be conveyed on aerial particulate matter such as dust and allergens. The transmission of respiratory viruses may then best be viewed as resulting from dynamic virus spread from infected individuals to susceptible individuals by various physical states of active respiratory emissions, instead of the current paradigm that emphasizes separate dissemination by respiratory droplets, aerosols or by contaminated fomites. To achieve the optimum outcome in terms of risk mitigation and infection prevention and control (IPAC) during seasonal infection peaks, outbreaks, and pandemics, this holistic view emphasizes the importance of dealing with all interdependent transmission modalities, rather than focusing on one modality.

Aspects and problems associated with the water services to be considered in intensive care units

Background

Water is a product taken for granted and assumed to be a safe commodity in intensive care units (ICU). Biofilm readily becomes established in complex water services presenting a risk to vulnerable patients. Harboured within biofilms are opportunistic pathogens which can be transmitted via hand contact, splashing, aerosol and indirect contact through medical equipment. Evidence linking the role of water services in transmission of infection to patients in ICUs has increased in recent years.

Aims

This research based commentary set out to identify current problems with water and wastewater systems in ICU settings.

Methods

Databases and open source information was used to obtain data on current water and wastewater-related issues in ICU settings. This and the authors experiences have been used to describe current challenges.

Findings

the authors found a number of problems with water systems in ICU to which there has not been a cohesive response in terms of guidance to support users and designers. The resultant void permits new projects to proceed with suboptimal and designs which place patients and staff at risk.

Discussion

Hand hygiene stations are frequently misused or close enough to patients such that splashing poses a transmission risk. The wastewater system (drain) also presents a risk, from where Gram-negative antibiotic resistant organisms may be dispersed resulting in untreatable patient infections. The water and wastewater system provide a superhighway for the movement of pathogenic microorganisms and these risks need to be addressed if we are to safeguard vulnerable users in ICU.

Antimicrobial Performance of Innovative Functionalized Surfaces Based on Enamel Coatings: The Effect of Silver-Based Additives on the Antibacterial and Antifungal Activity

Frequently touched surfaces (FTS) that are contaminated with pathogens are one of the main sources of nosocomial infections, which commonly include hospital-acquired and healthcare-associated infections (HAIs). HAIs are considered the most common adverse event that has a significant burden on the public's health worldwide currently. The persistence of pathogens on contaminated surfaces and the transmission of multi-drug resistant (MDR) pathogens by way of healthcare surfaces, which are frequently touched by healthcare workers, visitors, and patients increase the risk of acquiring infectious agents in hospital environments. Moreover, not only in hospitals but also in high-traffic public places, FTS play a major role in the spreading of pathogens. Consequently, attention has been devoted to developing novel and alternative methods to tackle this problem. This study planned to produce and characterize innovative functionalized enameled coated surfaces supplemented with 1% AgNO₃ and 2% AgNO₃. Thus, the antimicrobial properties of the enamels against relevant nosocomial pathogens including the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli and the yeast Candida albicans were assessed using the ISO:22196:2011 norm.

Commercial toilets emit energetic and rapidly spreading aerosol plumes

Aerosols can transmit infectious diseases including SARS-CoV-2, influenza and norovirus. Flushed toilets emit aerosols that spread pathogens contained in feces, but little is known about the spatiotemporal evolution of these plumes or the velocity fields that transport them. Using laser light to illuminate ejected aerosols we quantify the kinematics of plumes emanating from a commercial flushometer-type toilet, and use the motion of aerosol particles to compute velocity fields of the associated flow. The toilet flush produces a strong chaotic jet with velocities exceeding 2 m/s; this jet transports aerosols to heights reaching 1.5 m within 8 seconds of initiating a flush. Quantifying toilet plumes and associated flow velocities provides a foundation for future design strategies to mitigate plume formation or to disinfect pathogens within it.

Effect of availability and COVID-19 vaccination on food shopping and consumption behaviors among Jordan universities students

The COVID-19 pandemic influenced the lives of university students all across the globe. Indeed, the pandemic has impacted many aspects of their daily routine, changing their social and health habits and food-related behaviors. There is now no approved therapy, and vaccination is the only clinical preventative measure that provides the highest protection against the virus. While these vaccines have been beneficial in curbing the pandemic's effect, they may also influence food-related behaviors. Accordingly, this paper aims to investigate the impact of vaccination availability on university students' food shopping and consumption habits, vaccine-related opinions, and back on-campus behaviors in Jordan. The research is based on an online survey conducted in Jordan using a structured questionnaire and distributed through Google Forms between January 1 and March 20, 2022. A total of 624 valid answers were collected. The findings revealed no significant changes in the way students consumed, shopped, and handled food compared to the pre-vaccine period. However, there is a slight post-vaccine trend toward shopping more groceries online and ordering more meals via delivery apps and takeout services. Regarding health-related food choices, there was an increase in the consumption of healthy food, water, and fruits and vegetables. Further, following the availability of the vaccination, students' adoption of COVID-19 food-related habits was maintained. Gender, engagement in food preparation activities, and living status (e.g., whether or not living with parents) substantially affected several food-related behaviors. The findings are expected to guide both current emergency preparations and long-term food-related policies in Jordan. This information may also be helpful to researchers interested in the effects of COVID-19 vaccination on student nutrition and related food behaviors.

Risk factors for SARS-CoV-2 transmission in student residences: a case-ascertained study

Background

We aimed to investigate the overall secondary attack rates (SAR) of COVID-19 in student residences and to identify risk factors for higher transmission.

Methods

We retrospectively analysed the SAR in living units of student residences which were screened in Leuven (Belgium) following the detection of a COVID-19 case. Students were followed up in the framework of a routine testing and tracing follow-up system. We considered residence outbreaks followed up between October 30th 2020 and May 25th 2021. We used generalized estimating equations (GEE) to evaluate the impact of delay to follow-up, shared kitchen or sanitary facilities, the presence of a known external infection source and the recent occurrence of a social gathering. We used a generalized linear mixed model (GLMM) for validation.

Results

We included 165 student residences, representing 200 residence units (N screened residents = 2324). Secondary transmission occurred in 68 units which corresponded to 176 secondary cases. The overall observed SAR was 8.2%. In the GEE model, shared sanitary facilities (p = 0.04) and the recent occurrence of a social gathering (p = 0.003) were associated with a significant increase in SAR in a living unit, which was estimated at 3% (95%CI 1.5-5.2) in the absence of any risk factor and 13% (95%CI 11.4-15.8) in the presence of both. The GLMM confirmed these findings.

Conclusions

Shared sanitary facilities and the occurrence of social gatherings increase the risk of COVID-19 transmission and should be considered when screening and implementing preventive measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00966-4.

Malaria Publications before and during COVID-19 Pandemic: A Bibliometric Analysis

Coronavirus disease 2019 (COVID-19) has been reported to affect malaria intervention strategies, the suspension of malaria elimination programs, and the publication of malaria research. We compared differences in authorship, affiliations, countries, funding sources, article types, keywords, languages, and citations between studies published before and during the COVID-19 pandemic. The searches were performed online using the Scopus database on 8 April 2022. The searches were limited to two periods: before the COVID-19 pandemic (2018–2019) and during the COVID-19 pandemic (2020–2021). The information of authorship, affiliations, countries, funding sources, article types, keywords, languages, and citations between studies published before and during the COVID-19 pandemic were compared using frequency and percentage. The relationships between the most productive authors, countries, affiliations, journals, and frequently used keywords were visualized using the VOSviewer (version 1.6.18) software. A total of 2965 articles were identified in two periods and, among those, 1291 relevant studies were included. There was no difference in malaria publications before and during the COVID-19 pandemic (679 articles, 52.6% vs. 612 articles, 47.4%). Compared between the two periods, the preliminary trend of malaria publications in terms of authorship, affiliations, countries, funding sources, article types, keywords, languages, and citations were different. In conclusion, the current study showed the preliminary trends in malaria publications before and during the COVID-19 pandemic. The findings of this study would encourage researchers to perform a scoping review or systematic review to better understand the direction of malaria publications during the COVID-19 pandemic.

Biological Properties of SARS-CoV-2 Variants: Epidemiological Impact and Clinical Consequences

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus that belongs to the coronavirus family and is the cause of coronavirus disease 2019 (COVID-19). As of May 2022, it had caused more than 500 million infections and more than 6 million deaths worldwide. Several vaccines have been produced and tested over the last two years. The SARS-CoV-2 virus, on the other hand, has mutated over time, resulting in genetic variation in the population of circulating variants during the COVID-19 pandemic. It has also shown immune-evading characteristics, suggesting that vaccinations against these variants could be potentially ineffective. The purpose of this review article is to investigate the key variants of concern (VOCs) and mutations of the virus driving the current pandemic, as well as to explore the transmission rates of SARS-CoV-2 VOCs in relation to epidemiological factors and to compare the virus's transmission rate to that of prior coronaviruses. We examined and provided key information on SARS-CoV-2 VOCs in this study, including their transmissibility, infectivity rate, disease severity, affinity for angiotensin-converting enzyme 2 (ACE2) receptors, viral load, reproduction number, vaccination effectiveness, and vaccine breakthrough.

Big Data-Driven Measurement of the Service Capacity of Public Toilet Facilities in China

Public health facility planning is one of the important contents of national land planning, which needs to balance geospatial equity and service capacity. However, assessment models and data acquisition methods based on a geosystemic analysis perspective have been lacking for a long time. By focusing on urban public toilets and taking the highly urbanized city of Shenyang, China as the study area, this study developed a new data strategy for urban public facilities with points of interests (POI) big data as the main data source, and subsequently corrected the POI data and analyzed the errors through a field survey, and conducted an empirical assessment oriented toward spatial equity and service capacity to discover the development dynamics of urban facilities over the past ten years and the impacting factors. We found that the integrated population and spatial elements could more accurately evaluate the service capacity of public toilets. Meanwhile, POI data have value in the research of public health facilities, but there are some errors in data quality and data access. The study empirically explores the geographic analysis methods of field research data (small data) and POI data (big data) with empirical contributions.

Antimicrobial-Resistant Escherichia coli Distribution and Whole-Genome Analysis of Sequence Type 131 Escherichia coli Isolates in Public Restrooms in Taiwan

The threat of antibiotic-resistant bacteria to public health may originate from public restrooms. To better understand the community burden of antimicrobial-resistant Escherichia coli and sequence type complex 131 E. coli (STc131) in the public restroom, we performed a surveillance in public restrooms in southern Taiwan. Swabs were sampled from randomly selected public restrooms in Tainan, Taiwan in 2019. Antimicrobial susceptibility, phylogenetic grouping, and multiplex PCR were performed for the major ST complex in the B2 phylogenetic group. If STc131 isolates were identified, the whole-genome sequencing was performed. A total of 613 collection sites found 132 sites (21.5%) positive for E. coli. The most common phylogenetic group was A (30.9%) followed by B2 (30.3%). Ceftriaxone-resistant E. coli and extended-spectrum β-lactamases–producing E. coli were found in 2.4 and 1.0% of total public restrooms, respectively. The isolates in rural areas had higher ceftriaxone non-susceptibility than those in the city centers (3.9 vs. 1.2%, P = 0.038). Nine STc131 isolates were found in public restrooms, and most (77.8%) belonged to the subtype fimH41, whereas 22.2% belonged to fimH30. With the inclusion of STc131 isolates from human and dog fecal colonization in Taiwan, whole-genome sequencing was performed in 35 isolates. A large cluster of fimH41 in SNP-tree and GrapeTree was found from different sources (human, dog, and environment) and geographical areas. In conclusion, our surveillance of antimicrobial-resistant E. coli showed a higher prevalence of E. coli detected in public restrooms in the rural areas compared to those in city centers. The whole-genome sequence implies that fimH41 STc131 strains are successfully circulated in the community in Taiwan.

On male urination and related environmental disease transmission in restrooms: From the perspectives of fluid dynamics

Indoor transmission of COVID-19 is highly probable. Multiple sources have verified that the SARS-CoV-2 can be detected within toilets, and people can be infected in restrooms. There is a huge gap in the coronavirus transmission mechanism in restrooms. Understanding it can help to flatten the curve of the infected cases as well as prevent other viruses transmitted through the sewage or human body fluid. Previous studies have shown how simple actions in daily life (coughing, sneezing, or toilet flushing) contribute to virus transmission. This paper visually and quantitatively demonstrates that male urination, which is also a daily action, can agitate virus particles within the toilet and raise them, which may be the main promoter of cross-infection of COVID-19 in restrooms. Adopting numerical and experimental methods, we demonstrate that male urination can cause strong turbulent flow with an averaged urine impinging velocity of 2.3 m/s, which can act as an agitator to raise the virus particles. The climbing velocity of the airflow can be 0.75-1.05 m/s. The observed upwards flow will disturb and spread any lurking virus particles (not limited to SARS-CoV-2). Experiments demonstrated that the concentration of the airborne particle could be tripled during male urination. Corresponding precautions are offered as well to prepare the public to act properly when and after using facilities in restrooms for preventing emerging and re-emerging pandemics not limited to the current COVID-19, contributing to the sustainability of human society.

Transmission of SARS-CoV-2 infections and exposure in surfaces, points and wastewaters: A global one health perspective

The persistence of SARS-CoV-2 or its RNA on surfaces, points, or wastewaters may increase the risk of transmission of this virus. Therefore, we conducted this review to discuss the places and surfaces with the highest potential for infection and spread of the SARS-CoV-2 virus. Several common and public areas, hospitals, elevators, public transport, local markets, and surfaces such as public toilets, door handles, untreated and treated wastewaters, wastewater plants, and public washrooms are also considered major points for spreading of SARS-CoV-2. Highly contaminated surfaces or places often have materials or contain items made of materials on which the SARS-CoV-2 virus can persist (e.g., metal, wood, and plastic). For example, SARS-CoV-2 can exist up to 4 days on doorknobs made by those materials. For public places such as public transports, elevators, and local markets, crowding and enclosed spaces are major source for transmission. Several measures such as using copper alloy surfaces instead of metal surfaces, disinfectants, and suitable personal protective equipment have been suggested. Our research could be the basis to help develop studies on the existence and transmissibility of SARS-CoV-2 as well as its RNA to take measures to prevent and limit the harmful effects of COVID-19 pandemic.

[Low risk of environmental contagion by SARS-CoV-2 in non-sanitary spaces]

Objetivo

Estudiar la presencia de SARS-CoV-2 en superficies (alto, medio y bajo contacto) y aires de espacios no sanitarios pero de elevada afluencia de público para evaluar el riesgo de contagio ambiental.

Método

Se ha realizado el análisis de las superficies y de los aires por RT-qPCR para detectar la presencia de SARS-CoV-2.

Resultados

Se obtuvieron 394 superficies y 23 muestras de aire de espacios de alta afluencia de personas, como oficinas, centros comerciales y residencias de ancianos. El virus no fue detectado en ninguna de las muestras analizadas.

Conclusión

Aunque no podemos concluir rotundamente que no existe un riesgo de infección ambiental por SARS-CoV-2 en espacios no sanitarios, sí podemos afirmar que el riesgo es casi nulo.

Aerosols and Bacteria From Hand Washing and Drying in Indoor Air

Effective hand drying is an important part of hand hygiene that can reduce the risk of infectious disease transmission through cross-contamination of surfaces by wet hands. However, hand drying methods may also cause aerosolisation of pathogenic microorganisms if they are present in washed hands. This study investigated experimentally the impact of washing hands and different hand drying methods on the concentration and size distribution of aerosols and bacteria in indoor air. In this experiment, aerosol and bacteria concentrations were measured in indoor air while volunteers rinsed their hands with water or washed with soap and water prior to drying them with paper towels or jet air dryers. Results showed that the concentration of aerosols and bacteria in air increased with people walking in the room and washing hands, with a further increase during the hand drying process. The concentration of aerosols decreased with particle size, with maximum concentrations after drying hands of 6.63 × 10⁶ ± 6.49 × 10⁵ and 2.28 × 10⁴ ± 9.72 × 10³ particles m⁻³ for sizes 0.3 to <0.5 and ≥5.0 μm, respectively. The concentration of bacteria in indoor air after drying hands increased to a maximum of 3.81 × 10² ± 1.48 × 10² CFU m⁻³ (jet air dryers) and 4.50 × 10² ± 4.35 × 10¹ CFU m⁻³ (paper towels). This study indicates that the increase of aerosols and bacteria in air after drying hands with jet air dryers or paper towels are comparable and not statistically different from concentrations associated with walking and washing hands in the same environment. This work can support the development of hand hygiene practices and guidelines for public washrooms.

Longitudinal, virological, and serological assessment of hospitalized COVID-19 patients

Here we described the virological and serological assessment of 23 COVID-19 patients hospitalized and followed up in Milan, Italy, during the first wave of COVID-19 pandemic. Nasopharyngeal (NPS), anal swabs, and blood samples were collected from 23 COVID-19 patients, at hospital admission, and periodically up to discharge, for a median time of 20 days (3-83 days). RNA was isolated and tested for SARS-CoV-2 by qRT-PCR; anti-SARS-CoV-2 IgM and IgG antibody titers were evaluated in serum samples by ELISA. SARS-CoV-2 genome was detected in the NPS swabs of the 23 patients, at the admission, and 8/19 (42.1%) were still positive at the discharge. Anal swabs were positive to SARS-CoV-2 RNA detection in 20/23 (86.9%) patients; 6/19 (31.6%) were still positive at discharge. The mean time of RNA negative conversion was 17 days (4-36 days) and 33 days (4-77 days), for NPS and anal swabs, respectively. SARS-CoV-2-RNA was detected in the blood of 6/23 (26.1%) patients. Thirteen/23 (56.5%) and 17/23 (73.9%) patients were seropositive for IgM and IgG, respectively, at the admission, and the median IgM and IgG levels significantly (p < 0.05) increased after 13 days. Although the limited cohort size, our report provides evidence that SARS-CoV-2 is shed through multiple routes, with important implications in healthcare settings.