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1.
PLoS One ; 16(12): e0261321, 2021.
Article in English | MEDLINE | ID: covidwho-1639116

ABSTRACT

By September 2020, COVID-19 had claimed the lives of almost 1 million people worldwide, including more than 400,000 in the U.S. and Europe [1] To slow the spread of the virus, health officials advised social distancing, regular handwashing, and wearing a face covering [2]. We hypothesized that public adherence to the health guidance would be influenced by prevailing social norms, and the prevalence of these behaviors among others. We focused on mask-wearing behavior during fall 2020, and coded livestream public webcam footage of 1,200 individuals across seven cities. Results showed that only 50% of participants were correctly wearing a mask in public, and that this percentage varied as a function of the mask-wearing behavior of close and distant others in the immediate physical vicinity. How social normative information might be used to increase mask-wearing behavior is discussed. "Cloth face coverings are one of the most powerful weapons we have to slow and stop the spread of the virus-particularly when used universally within a community setting" CDC Director Dr. Robert Redfield in July 2020.


Subject(s)
COVID-19 , Masks/statistics & numerical data , Pandemics/statistics & numerical data , Social Behavior , Adult , COVID-19/epidemiology , COVID-19/psychology , Female , Humans , Male , Middle Aged
2.
PLoS One ; 16(12): e0261330, 2021.
Article in English | MEDLINE | ID: covidwho-1638355

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present an agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination. Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020. Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model infects only around 23% of the resident population. Our simulations suggest that testing and contract tracing reduce cases substantially, but are less effective at reducing deaths. Lockdowns are very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low coverage, with substantial levels of protection achieved with only 30% of the population fully immune. When vaccinating in the midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy. We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19.


Subject(s)
COVID-19/epidemiology , Pandemics/prevention & control , Quarantine/statistics & numerical data , Vaccination/statistics & numerical data , Adolescent , Adult , Aged , Child , Child, Preschool , Contact Tracing/statistics & numerical data , Humans , Immunity, Herd , Infant , Infant, Newborn , Luxembourg/epidemiology , Masks/statistics & numerical data , Middle Aged , Young Adult
3.
PLoS One ; 17(1): e0261398, 2022.
Article in English | MEDLINE | ID: covidwho-1631249

ABSTRACT

OBJECTIVES: To quantify changes in adherence to mask and distancing guidelines in outdoor settings in Philadelphia, PA before and after President Trump announced he was infected with COVID-19. METHODS: We used Systematic Observation of Masking Adherence and Distancing (SOMAD) to assess mask adherence in parks, playgrounds, and commercial streets in the 10 City Council districts in Philadelphia PA. We compared adherence rates between August and September 2020 and after October 2, 2020. RESULTS: Disparities in mask adherence existed by age group, gender, and race/ethnicity, with females wearing masks correctly more often than males, seniors having higher mask use than other age groups, and Asians having higher adherence than other race/ethnicities. Correct mask use did not increase after the City released additional mask guidance in September but did after Oct 2. Incorrect mask use also decreased, but the percentage not having masks at all was unchanged. CONCLUSIONS: Vulnerability of leadership appears to influence population behavior. Public health departments likely need more resources to effectively and persuasively communicate critical safety messages related to COVID-19 transmission.


Subject(s)
COVID-19/epidemiology , Masks/trends , Adolescent , Adult , Aged , COVID-19/virology , Child , Child, Preschool , Female , Guideline Adherence/trends , Humans , Male , Masks/statistics & numerical data , Middle Aged , Philadelphia , Physical Distancing , Public Health , SARS-CoV-2/isolation & purification , Young Adult
4.
Neurol Neuroimmunol Neuroinflamm ; 9(1)2022 01.
Article in English | MEDLINE | ID: covidwho-1596607

ABSTRACT

BACKGROUND AND OBJECTIVES: To investigate whether children receiving immunosuppressive therapies for neuroimmunologic disorders had (1) increased susceptibility to SARS-CoV2 infection or to develop more severe forms of COVID-19; (2) increased relapses or autoimmune complications if infected; and (3) changes in health care delivery during the pandemic. METHODS: Patients with and without immunosuppressive treatment were recruited to participate in a retrospective survey evaluating the period from March 14, 2020, to March 30, 2021. Demographics, clinical features, type of immunosuppressive treatment, suspected or confirmed COVID-19 in the patients or cohabitants, and changes in care delivery were recorded. RESULTS: One hundred fifty-three children were included: 84 (55%) female, median age 13 years (interquartile range [8-16] years), 79 (52%) on immunosuppressive treatment. COVID-19 was suspected or confirmed in 17 (11%) (all mild), with a frequency similar in patients with and without immunosuppressive treatment (11/79 [14%] vs 6/74 [8%], p = 0.3085). The frequency of neurologic relapses was similar in patients with (18%) and without (21%) COVID-19. Factors associated with COVID-19 included having cohabitants with COVID-19 (p < 0.001) and lower blood levels of vitamin D (p = 0.039). Return to face-to-face schooling or mask type did not influence the risk of infection, although 43(28%) children had contact with a classmate with COVID-19. Clinic visits changed from face to face to remote for 120 (79%) patients; 110 (92%) were satisfied with the change. DISCUSSION: In this cohort of children with neuroimmunologic disorders, the frequency of COVID-19 was low and not affected by immunosuppressive therapies. The main risk factors for developing COVID-19 were having cohabitants with COVID-19 and low vitamin D levels.


Subject(s)
COVID-19/complications , COVID-19/immunology , Immunocompromised Host , Immunosuppressive Agents/adverse effects , Nervous System Diseases/complications , Nervous System Diseases/immunology , SARS-CoV-2/immunology , Adolescent , COVID-19/prevention & control , COVID-19/virology , Child , Delivery of Health Care/organization & administration , Delivery of Health Care/statistics & numerical data , Female , Humans , Immunosuppressive Agents/therapeutic use , Male , Masks/statistics & numerical data , Masks/virology , Nervous System Diseases/virology , Pandemics , Recurrence , Retrospective Studies , Vitamin D/blood
5.
Sci Rep ; 11(1): 24490, 2021 12 29.
Article in English | MEDLINE | ID: covidwho-1594104

ABSTRACT

During the first wave of Covid-19 infections in Germany in April 2020, clinics reported a shortage of filtering face masks with aerosol retention> 94% (FFP2 & 3, KN95, N95). Companies all over the world increased their production capacities, but quality control of once-certified materials and masks came up short. To help identify falsely labeled masks and ensure safe protection equipment, we tested 101 different batches of masks in 993 measurements with a self-made setup based on DIN standards. An aerosol generator provided a NaCl test aerosol which was applied to the mask. A laser aerosol spectrometer measured the aerosol concentration in a range from 90 to 500 nm to quantify the masks' retention. Of 101 tested mask batches, only 31 batches kept what their label promised. Especially in the initial phase of the pandemic in Germany, we observed fluctuating mask qualities. Many batches show very high variability in aerosol retention. In addition, by measuring with a laser aerosol spectrometer, we were able to show that not all masks filter small and large particles equally well. In this study we demonstrate how important internal and independent quality controls are, especially in times of need and shortage of personal protection equipment.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Masks/statistics & numerical data , Aerosols , Filtration/instrumentation , Germany , Humans , Masks/standards , Masks/trends , N95 Respirators/standards , N95 Respirators/statistics & numerical data , Occupational Exposure/prevention & control , Pandemics/prevention & control , Personal Protective Equipment/standards , Quality Control , Respiratory Protective Devices/standards , SARS-CoV-2/pathogenicity
6.
Gac Med Mex ; 157(3): 277-283, 2021.
Article in English | MEDLINE | ID: covidwho-1535085

ABSTRACT

INTRODUCTION: Currently, the face mask represents an incomparable symbol whose value went from clinical work to impacting the containment of the spread of SARS-CoV-2, although it has become an element of discord in the general population. OBJECTIVE: To establish the impact of face mask use policies on COVID-19 morbidity and mortality. METHODS: Face mask use policy variables, obtained from the website of the #Masks4All scientific movement, were associated with the number of infections, deaths and flattening of the curve published by the Johns Hopkins University resource center and EndCoronavirus.org. RESULTS: Face mask use policies were universal (required in shops, restaurants, public transport), partial (recommended, required in any public place) and absent. Associations of the face mask use policy with total cases (p = 0.01), cases per million (p = 0.04) and deaths per million population (p = 0.02) were statistically significant. Associations of the variables with the epidemiological curve trend were also statistically significant (p = 0.00). CONCLUSION: The recommendation for face mask widespread use is a measure with sufficient scientific support to reduce the number of COVID-19-related infections and deaths.


Subject(s)
COVID-19/prevention & control , Health Policy , Masks/statistics & numerical data , COVID-19/epidemiology , COVID-19/mortality , Cross-Sectional Studies , Global Health , Humans
7.
Sci Rep ; 11(1): 21675, 2021 11 04.
Article in English | MEDLINE | ID: covidwho-1504246

ABSTRACT

The recent outbreak of the COVID-19 led to death of millions of people worldwide. To stave off the spread of the virus, the authorities in the US employed different strategies, including the mask mandate order issued by the states' governors. In the current work, we defined a parameter called average death ratio as the monthly average of the number of daily deaths to the monthly average number of daily cases. We utilized survey data to quantify people's abidance by the mask mandate order. Additionally, we implicitly addressed the extent to which people abide by the mask mandate order, which may depend on some parameters such as population, income, and education level. Using different machine learning classification algorithms, we investigated how the decrease or increase in death ratio for the counties in the US West Coast correlates with the input parameters. The results showed that for the majority of counties, the mask mandate order decreased the death ratio, reflecting the effectiveness of such a preventive measure on the West Coast. Additionally, the changes in the death ratio demonstrated a noticeable correlation with the socio-economic condition of each county. Moreover, the results showed a promising classification accuracy score as high as 90%.


Subject(s)
COVID-19/mortality , COVID-19/prevention & control , Masks/trends , California , Guideline Adherence/trends , Health Policy , Humans , Machine Learning , Masks/statistics & numerical data , Oregon , SARS-CoV-2/pathogenicity , Washington
9.
Biomedica ; 41(Sp. 2): 48-61, 2021 10 15.
Article in English, Spanish | MEDLINE | ID: covidwho-1478423

ABSTRACT

INTRODUCTION: The studies on knowledge, attitudes, and practices (KAP) regarding COVID-19 help to identify erroneous concepts and inadequate practices related to the disease. This baseline information is essential to design effective strategies and improve adherence to prevention measures. OBJECTIVE: To identify the COVID-19-related KAP in Venezuelan patients screened at the Hospital Universitario de Caracas triage tent. MATERIALS AND METHODS: We conducted a cross-sectional study among 215 patients between April 25th and May 25th, 2020, with in-person interviews using a KAP survey. RESULTS: Most surveyed patients (53.5%) were asymptomatic. Most of them, both from the symptomatic and the asymptomatic groups, had adequate knowledge about the symptoms and transmission of the disease and the majority said they were practicing quarantine, frequent handwashing, and the use of face masks in public areas. However, the daily replacement of cloth face masks was more frequent in the asymptomatic group whereas replacement every three days was more frequent in the symptomatic group. Finally, more than half of the participants admitted having been in crowded places, a common practice among the symptomatic compared to the asymptomatic patients. CONCLUSIONS: This is the first KAP study in Venezuela about COVID-19. Knowledge and practices among Venezuelans could be improved by strengthening education and training programs. This information from the early phase of the pandemic in Venezuela may contribute to the design of COVID-19 promotion and prevention strategies.


Introducción: Los estudios sobre conocimientos, actitudes y prácticas (CAP) sobre COVID-19 ayudan a identificar conceptos erróneos y prácticas inadecuadas relacionadas con la enfermedad. Esta información de referencia es fundamental para diseñar estrategias efectivas y mejorar la adherencia a las medidas de prevención. Objetivo: Identificar la CAP relacionada con COVID-19 en pacientes venezolanos cribados en la carpa de triaje del Hospital Universitario de Caracas. Materiales y métodos: Realizamos un estudio transversal entre 215 pacientes entre el 25 de abril y el 25 de mayo de 2020, con entrevistas en persona utilizando una encuesta KAP. Resultados: La mayoría de los pacientes encuestados (53,5%) se encontraban asintomáticos. La mayoría de ellos, tanto del grupo sintomático como asintomático, tenían un conocimiento adecuado sobre los síntomas y la transmisión de la enfermedad y la mayoría dijo que practicaban la cuarentena, el lavado frecuente de manos y el uso de mascarillas en las áreas públicas. Sin embargo, el reemplazo diario de mascarillas de tela fue más frecuente en el grupo asintomático, mientras que el reemplazo cada tres días fue más frecuente en el grupo sintomático. Finalmente, más de la mitad de los participantes admitieron haber estado en lugares concurridos, una práctica común entre los sintomáticos en comparación con los asintomáticos. Conclusiones: Este es el primer estudio CAP en Venezuela sobre COVID-19. El conocimiento y las prácticas entre los venezolanos podrían mejorarse fortaleciendo los programas de educación y capacitación. Esta información de la fase inicial de la pandemia en Venezuela puede contribuir al diseño de estrategias de promoción y prevención del COVID-19.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Health Knowledge, Attitudes, Practice , Adult , Asymptomatic Infections/epidemiology , Cross-Sectional Studies , Crowding , Female , Hand Disinfection , Health Surveys/methods , Health Surveys/statistics & numerical data , Humans , Male , Masks/statistics & numerical data , Physical Distancing , Symptom Assessment , Triage , Venezuela/epidemiology
11.
PLoS One ; 16(10): e0258191, 2021.
Article in English | MEDLINE | ID: covidwho-1456093

ABSTRACT

Face coverings are a key component of preventive health measure strategies to mitigate the spread of respiratory illnesses. In this study five groups of masks were investigated that are of particular relevance to the SARS-CoV-2 pandemic: re-usable, fabric two-layer and multi-layer masks, disposable procedure/surgical masks, KN95 and N95 filtering facepiece respirators. Experimental work focussed on the particle penetration through mask materials as a function of particle diameter, and the total inward leakage protection performance of the mask system. Geometric mean fabric protection factors varied from 1.78 to 144.5 for the fabric two-layer and KN95 materials, corresponding to overall filtration efficiencies of 43.8% and 99.3% using a flow rate of 17 L/min, equivalent to a breathing expiration rate for a person in a sedentary or standing position conversing with another individual. Geometric mean total inward leakage protection factors for the 2-layer, multi-layer and procedure masks were <2.3, while 6.2 was achieved for the KN95 masks. The highest values were measured for the N95 group at 165.7. Mask performance is dominated by face seal leakage. Despite the additional filtering layers added to cloth masks, and the higher filtration efficiency of the materials used in disposable procedure and KN95 masks, the total inward leakage protection factor was only marginally improved. N95 FFRs were the only mask group investigated that provided not only high filtration efficiency but high total inward leakage protection, and remain the best option to protect individuals from exposure to aerosol in high risk settings. The Mask Quality Factor and total inward leakage performance are very useful to determine the best options for masking. However, it is highly recommended that testing is undertaken on prospective products, or guidance is sought from impartial authorities, to confirm they meet any implied standards.


Subject(s)
Filtration/instrumentation , Masks/statistics & numerical data , N95 Respirators/statistics & numerical data , Textiles , Equipment Reuse , Inhalation Exposure/prevention & control
12.
MMWR Morb Mortal Wkly Rep ; 70(39): 1377-1378, 2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1444556

ABSTRACT

Consistent and correct mask use is a critical strategy for preventing the transmission of SARS-CoV-2, the virus that causes COVID-19 (1). CDC recommends that schools require universal indoor mask use for students, staff members, and others in kindergarten through grade 12 (K-12) school settings (2). As U.S. schools opened for the 2021-22 school year in the midst of increasing community spread of COVID-19, some states, counties, and school districts implemented mask requirements in schools. To assess the impact of masking in schools on COVID-19 incidence among K-12 students across the United States, CDC assessed differences between county-level pediatric COVID-19 case rates in schools with and without school mask requirements.


Subject(s)
COVID-19/epidemiology , COVID-19/prevention & control , Masks/statistics & numerical data , Schools/statistics & numerical data , Adolescent , Child , Child, Preschool , Humans , United States/epidemiology
13.
MMWR Morb Mortal Wkly Rep ; 70(39): 1372-1373, 2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1444554

ABSTRACT

CDC recommends universal indoor masking by students, staff members, faculty, and visitors in kindergarten through grade 12 (K-12) schools, regardless of vaccination status, to reduce transmission of SARS-CoV-2, the virus that causes COVID-19 (1). Schools in Maricopa and Pima Counties, which account for >75% of Arizona's population (2), resumed in-person learning for the 2021-22 academic year during late July through early August 2021. In mid-July, county-wide 7-day case rates were 161 and 105 per 100,000 persons in Maricopa and Pima Counties, respectively, and 47.6% of Maricopa County residents and 59.2% of Pima County residents had received at least 1 dose of a COVID-19 vaccine. School districts in both counties implemented variable mask policies at the start of the 2021-22 academic year (Table). The association between school mask policies and school-associated COVID-19 outbreaks in K-12 public noncharter schools open for in-person learning in Maricopa and Pima Counties during July 15-August 31, 2021, was evaluated.


Subject(s)
COVID-19/prevention & control , Disease Outbreaks/statistics & numerical data , Masks/statistics & numerical data , Organizational Policy , Schools/organization & administration , Adolescent , Arizona/epidemiology , COVID-19/epidemiology , Child , Child, Preschool , Humans
14.
MMWR Morb Mortal Wkly Rep ; 70(36): 1245-1248, 2021 Sep 10.
Article in English | MEDLINE | ID: covidwho-1441396

ABSTRACT

Universities open for in-person instruction during the 2020-21 academic year implemented a range of prevention strategies to limit the transmission of SARS-CoV-2, the virus that causes COVID-19, including physical distancing, mask use, vaccination, contact tracing, case investigation, and quarantine protocols (1). However, in some academic programs, such as health-related programs, aviation, and kindergarten through grade 12 (K-12) education, maintaining physical distance while still providing instruction is difficult; for universities with such programs, a single confirmed case of COVID-19 could result in a large number of students, staff members, and instructors being designated close contacts and requiring quarantine if they are not fully vaccinated, even if masks were worn when contact occurred. In January 2021, the St. Louis City Health Department allowed Saint Louis University (SLU) to implement a modified quarantine protocol that considered mask use when determining which close contacts required quarantine.* To assess the impact of the protocol, SLU assessed positive SARS-CoV-2 test result rates by masking status of the persons with COVID-19 and their close contacts. During January-May 2021, 265 students received a positive SARS-CoV-2 test result; these students named 378 close contacts. Compared with close contacts whose exposure only occurred when both persons were masked (7.7%), close contacts with any unmasked exposure (32.4%) had higher adjusted odds ratios (aORs) of receiving a positive SARS-CoV-2 test result (aOR = 4.9; 95% confidence interval [CI] = 1.4-31.1). Any additional exposures were associated with a 40.0% increase in odds of a positive test result (aOR = 1.4; 95% CI = 1.2-1.6). These findings reinforce that universal masking and having fewer encounters in close contact with persons with COVID-19 prevents the spread of SARS-CoV-2 in a university setting. Universities opening for in-person instruction could consider taking mask use into account when determining which unvaccinated close contacts require quarantine if enforced testing protocols are in place. However, this study was conducted before the B.1.617.2 (Delta) variant became the dominant strain of SARS-CoV-2 in the United States, which could have affected these findings given that the Delta variant has been found to be associated with increased transmissibility compared to previous variants.


Subject(s)
COVID-19/transmission , Contact Tracing , Masks/statistics & numerical data , Students/statistics & numerical data , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Testing , COVID-19 Vaccines/administration & dosage , Female , Humans , Male , Missouri/epidemiology , SARS-CoV-2/isolation & purification , Universities
15.
PLoS One ; 16(9): e0257052, 2021.
Article in English | MEDLINE | ID: covidwho-1416884

ABSTRACT

There remains a great challenge to minimize the spread of epidemics, especially in high-density communities such as colleges and universities. This is particularly true on densely populated, residential college campuses. To construct class and residential networks data from a four-year, residential liberal arts college with 5539 students were obtained from SUNY College at Geneseo, a rural, residential, undergraduate institution in western NY, USA. Equal-sized random networks also were created for each day. Different levels of compliance with mask use (none to 100%), mask efficacy (50% to 100%), and testing frequency (daily, or every 2, 3, 7, 14, 28, or 105 days) were assessed. Tests were assumed to be only 90% accurate and positive results were used to isolate individuals. The effectiveness of contact tracing, and the effect of quarantining neighbors of infectious individuals, was tested. The structure of the college course enrollment and residence networks greatly influenced the dynamics of the epidemics, as compared to the random networks. In particular, average path lengths were longer in the college networks compared to random networks. Students in larger majors generally had shorter average path lengths than students in smaller majors. Average transitivity (clustering) was lower on days when students most frequently were in class (MWF). Degree distributions were generally large and right skewed, ranging from 0 to 719. Simulations began by inoculating twenty students (10 exposed and 10 infectious) with SARS-CoV-2 on the first day of the fall semester and ended once the disease was cleared. Transmission probability was calculated based on an R0 = 2.4. Without interventions epidemics resulted in most students becoming infected and lasted into the second semester. On average students in the college networks experienced fewer infections, shorter duration, and lower epidemic peaks when compared to the dynamics on equal-sized random networks. The most important factors in reducing case numbers were the proportion masking and the frequency of testing, followed by contact tracing and mask efficacy. The paper discusses further high-order interactions and other implications of non-pharmaceutical interventions for disease transmission on a residential college campus.


Subject(s)
COVID-19/prevention & control , Contact Tracing/methods , Masks/statistics & numerical data , Pandemics/prevention & control , Universities/statistics & numerical data , Adolescent , Adult , Female , Humans , Male , New York/epidemiology , Quarantine/methods , Students , Young Adult
16.
MMWR Morb Mortal Wkly Rep ; 70(35): 1223-1227, 2021 Sep 03.
Article in English | MEDLINE | ID: covidwho-1413074

ABSTRACT

On June 30, 2021, the Illinois Department of Public Health (IDPH) contacted CDC concerning COVID-19 outbreaks at two events sponsored by the same organization: a 5-day overnight church camp for persons aged 14-18 years and a 2-day men's conference. Neither COVID-19 vaccination nor COVID-19 testing was required before either event. As of August 13, a total of 180 confirmed and probable cases had been identified among attendees at the two events and their close contacts. Among the 122 cases associated with the camp or the conference (primary cases), 18 were in persons who were fully vaccinated, with 38 close contacts. Eight of these 38 close contacts subsequently became infected with SARS-CoV-2, the virus that causes COVID-19 (secondary cases); among the eight close contacts with secondary cases, one half (four) were fully vaccinated. Among the 180 total persons with outbreak-associated cases, five (2.8%) were hospitalized; no deaths occurred. None of the vaccinated persons with cases were hospitalized. Approximately 1,000 persons across at least four states were exposed to SARS-CoV-2 through attendance at these events or through close contact with a person who had a primary case. This investigation underscores the impact of secondary SARS-CoV-2 transmission during large events, such as camps and conferences, when COVID-19 prevention strategies are not implemented. In Los Angeles County, California, during July 2021, when the SARS-CoV-2 B.1.617.2 (Delta) variant was predominant, unvaccinated residents were five times more likely to be infected and 29 times more likely to be hospitalized from infection than were vaccinated residents (1). Implementation of multiple prevention strategies, including vaccination and nonpharmaceutical interventions such as masking, physical distancing, and screening testing, are critical to preventing SARS-CoV-2 transmission and serious complications from COVID-19.


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , Camping , Congresses as Topic , Disease Outbreaks , Adolescent , Adult , Aged , COVID-19/prevention & control , COVID-19 Testing/statistics & numerical data , COVID-19 Vaccines/administration & dosage , Child , Child, Preschool , Contact Tracing , Female , Humans , Illinois/epidemiology , Male , Masks/statistics & numerical data , Middle Aged , Physical Distancing , Young Adult
17.
MMWR Morb Mortal Wkly Rep ; 70(35): 1214-1219, 2021 Sep 03.
Article in English | MEDLINE | ID: covidwho-1412877

ABSTRACT

On May 25, 2021, the Marin County Department of Public Health (MCPH) was notified by an elementary school that on May 23, an unvaccinated teacher had reported receiving a positive test result for SARS-CoV-2, the virus that causes COVID-19. The teacher reported becoming symptomatic on May 19, but continued to work for 2 days before receiving a test on May 21. On occasion during this time, the teacher read aloud unmasked to the class despite school requirements to mask while indoors. Beginning May 23, additional cases of COVID-19 were reported among other staff members, students, parents, and siblings connected to the school. To characterize the outbreak, on May 26, MCPH initiated case investigation and contact tracing that included whole genome sequencing (WGS) of available specimens. A total of 27 cases were identified, including that of the teacher. During May 23-26, among the teacher's 24 students, 22 students, all ineligible for vaccination because of age, received testing for SARS-CoV-2; 12 received positive test results. The attack rate in the two rows seated closest to the teacher's desk was 80% (eight of 10) and was 28% (four of 14) in the three back rows (Fisher's exact test; p = 0.036). During May 24-June 1, six of 18 students in a separate grade at the school, all also too young for vaccination, received positive SARS-CoV-2 test results. Eight additional cases were also identified, all in parents and siblings of students in these two grades. Among these additional cases, three were in persons fully vaccinated in accordance with CDC recommendations (1). Among the 27 total cases, 22 (81%) persons reported symptoms; the most frequently reported symptoms were fever (41%), cough (33%), headache (26%), and sore throat (26%). WGS of all 18 available specimens identified the B.1.617.2 (Delta) variant. Vaccines are effective against the Delta variant (2), but risk of transmission remains elevated among unvaccinated persons in schools without strict adherence to prevention strategies. In addition to vaccination for eligible persons, strict adherence to nonpharmaceutical prevention strategies, including masking, routine testing, facility ventilation, and staying home when symptomatic, are important to ensure safe in-person learning in schools (3).


Subject(s)
COVID-19/epidemiology , COVID-19/virology , Disease Outbreaks , SARS-CoV-2/isolation & purification , Schools , Adult , COVID-19/prevention & control , COVID-19/transmission , COVID-19 Vaccines/administration & dosage , California/epidemiology , Child , Contact Tracing , Humans , Masks/statistics & numerical data , School Teachers/statistics & numerical data
18.
West J Emerg Med ; 22(5): 1045-1050, 2021 Aug 17.
Article in English | MEDLINE | ID: covidwho-1405508

ABSTRACT

INTRODUCTION: The coronavirus 2019 (COVID-19) pandemic has reinforced the importance of facial protection against droplet transmission of diseases. Healthcare workers wear personal protection equipment (PPE), including face shields and masks. Plastic face shields may have advantages over regular medical masks. Although many designs of face shields exist, there is a paucity of evidence regarding the efficacy of shield designs against droplet transmissions. There is even less published evidence comparing various face shields. Due to the urgency of the pandemic and the health and safety of healthcare workers, we aimed to study the efficacy of various face shields against droplet transmission. METHODS: We simulated droplet transmission via coughing using a heavy-duty chemical spray bottle filled with fluorescein. A standard-adult sized mannequin head was used. The mannequin head wore various face shields and was positioned to face the spray bottle at either a 0°, 45°, or 90° angle. The spray bottle was positioned at and sprayed from 30 centimeters (cm), 60 cm, or 90 cm away from the head. These steps were repeated for all face shields used. Control was a mannequin that wore no PPE. A basic mask was also tested. We collected data for particle count, total area of particle distribution, average particle size, and percentage area covered by particles. We analyzed percent covered by particles using a repeated measures mixed-model regression with Tukey-Kramer pairwise comparison. RESULTS: We used least square means to estimate the percentage area covered by particles. Wearing PPE regardless of the design reduced particle transmission to the mannequin compared to the control. The LCG mask had the lowest square means of 0.06 of all face-shield designs analyzed. Tukey-Kramer pairwise comparison showed that all PPEs had a decrease in particle contamination compared to the control. LCG shield was found to have the least contamination compared to all other masks (P < 0.05). CONCLUSION: Results suggest the importance of wearing a protective covering against droplet transmission. The LCG shield was found to decrease facial contamination by droplets the most of any tested protective equipment.


Subject(s)
Aerosols/analysis , COVID-19/prevention & control , Infection Control , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Inhalation Exposure/prevention & control , Masks/statistics & numerical data , Personal Protective Equipment/statistics & numerical data , COVID-19/epidemiology , Cough , Delivery of Health Care , Humans , Manikins , Masks/standards , Particle Size , Personal Protective Equipment/standards , SARS-CoV-2
19.
PLoS One ; 16(9): e0257112, 2021.
Article in English | MEDLINE | ID: covidwho-1398939

ABSTRACT

Public health and social interventions are critical to mitigate the spread of the coronavirus disease 2019 (COVID-19) pandemic. Ethiopia has implemented a variety of public health and social measures to control the pandemic. This study aimed to assess social distancing and public health preventive practices of government employees in response to COVID-19. A cross-sectional study was conducted among 1,573 government employees selected from 46 public institutions located in Addis Ababa. Data were collected from 8th to 19th June 2020 using a paper-based self-administered questionnaire and analyzed using SPSS version 23.0. Descriptive statistics were used to summarize the data. Binary logistic regression analyses were used to identify factors associated with outcome variables (perceived effectiveness of facemask wearing to prevent coronavirus infection, and COVID-19 testing). Majority of the participants reported facemask wearing (96%), avoiding close contact with people including handshaking (94.8%), consistently followed government recommendations (95.6%), frequent handwashing (94.5%), practiced physical distancing (89.5%), avoided mass gatherings and crowded places (88.1%), restricting movement and travelling (71.8%), and stayed home (35.6%). More than 80% of the participants perceived that consistently wearing a facemask is highly effective in preventing coronavirus infection. Respondents from Oromia perceived less about the effectiveness of wearing facemask in preventing coronavirus infection (adjusted OR = 0.27, 95% CI:0.17-0.45). About 19% of the respondents reported that they had ever tested for COVID-19. Respondents between 40-49 years old (adjusted OR = 0.41, 95% CI:0.22-0.76) and 50-66 years (adjusted OR = 0.43, 95% CI:0.19-0.95) were less likely tested for coronavirus than the younger age groups. Similarly, respondents from Oromia were less likely to test for coronavirus (adjusted OR = 0.26, 95% CI:0.12-0.56) than those from national level. Participants who were sure about the availability of COVID-19 testing were more likely to test for coronavirus. About 57% of the respondents perceived that the policy measures in response to the pandemic were inadequate. The findings showed higher social distancing and preventive practices among the government employees in response to COVID-19. Rules and regulations imposed by the government should be enforced and people should properly apply wearing facemasks, frequent handwashing, social and physical distancing measures as a comprehensive package of COVID-19 prevention and control strategies.


Subject(s)
COVID-19/prevention & control , Government Employees/statistics & numerical data , Adolescent , Adult , COVID-19 Testing/statistics & numerical data , Cross-Sectional Studies , Ethiopia , Female , Hand Disinfection/methods , Humans , Male , Masks/statistics & numerical data , Pandemics/prevention & control , Pandemics/statistics & numerical data , Physical Distancing , Surveys and Questionnaires/statistics & numerical data , Young Adult
20.
MMWR Morb Mortal Wkly Rep ; 70(21): 779-784, 2021 May 28.
Article in English | MEDLINE | ID: covidwho-1395448

ABSTRACT

To meet the educational, physical, social, and emotional needs of children, many U.S. schools opened for in-person learning during fall 2020 by implementing strategies to prevent transmission of SARS-CoV-2, the virus that causes COVID-19 (1,2). To date, there have been no U.S. studies comparing COVID-19 incidence in schools that varied in implementing recommended prevention strategies, including mask requirements and ventilation improvements* (2). Using data from Georgia kindergarten through grade 5 (K-5) schools that opened for in-person learning during fall 2020, CDC and the Georgia Department of Public Health (GDPH) assessed the impact of school-level prevention strategies on incidence of COVID-19 among students and staff members before the availability of COVID-19 vaccines.† Among 169 K-5 schools that participated in a survey on prevention strategies and reported COVID-19 cases during November 16-December 11, 2020, COVID-19 incidence was 3.08 cases among students and staff members per 500 enrolled students.§ Adjusting for county-level incidence, COVID-19 incidence was 37% lower in schools that required teachers and staff members to use masks, and 39% lower in schools that improved ventilation, compared with schools that did not use these prevention strategies. Ventilation strategies associated with lower school incidence included methods to dilute airborne particles alone by opening windows, opening doors, or using fans (35% lower incidence), or in combination with methods to filter airborne particles with high-efficiency particulate absorbing (HEPA) filtration with or without purification with ultraviolet germicidal irradiation (UVGI) (48% lower incidence). Multiple strategies should be implemented to prevent transmission of SARS-CoV-2 in schools (2); mask requirements for teachers and staff members and improved ventilation are important strategies that elementary schools could implement as part of a multicomponent approach to provide safer, in-person learning environments. Universal and correct mask use is still recommended by CDC for adults and children in schools regardless of vaccination status (2).


Subject(s)
COVID-19/prevention & control , Masks/statistics & numerical data , Schools , Ventilation/standards , COVID-19/epidemiology , Child , Georgia/epidemiology , Humans , Incidence
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