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1.
Washington, D.C.; OPAS; 2022-01-03. (OPAS/PHE/IMS/COVID-19/21-0015).
Não convencional em Português | PAHO-IRIS | ID: phr-55545

RESUMO

Esta publicação da Organização Pan-Americana da Saúde (OPAS) é uma versão atualizada do documento Considerações para a implementação e gerenciamento de rastreamento de contatos para a doença causada pelo novo coronavírus (COVID-19) na Região das Américas, de junho de 2020, cujo objetivo é complementar a orientação provisória da Organização Mundial da Saúde (OMS) sobre o rastreamento de contatos no contexto da COVID-19. A presente publicação inclui orientações para o rastreamento de contatos entre contatos vacinados e viajantes internacionais e em ambientes com transmissão comunitária. Ela também inclui as definições atualizadas de casos, contatos e transmissão comunitária publicadas pela OMS. Busca fornecer orientações e recomendações operacionais para implementar o rastreamento de contatos de COVID-19 nas Américas. Ela será atualizada conforme o conhecimento atual sobre a COVID-19 evolua. O público-alvo desta publicação são autoridades sanitárias nacionais, profissionais de saúde pública e outros funcionários envolvidos na elaboração e implantação de políticas e procedimentos operacionais padrão relacionados a operações de rastreamento de contatos nas Américas.


Assuntos
COVID-19 , Coronavirus , Betacoronavirus , Infecções por Coronavirus , Vacinas contra COVID-19 , Transmissão de Doença Infecciosa , Busca de Comunicante , Microscopia Eletrônica de Transmissão e Varredura , Período de Transmissibilidade , Vacinas , Vacinação , Doenças Preveníveis por Vacina
2.
Washington, D.C.; OPS; 2022-01-03. (OPS/PHE/IMS/COVID-19/21-0015).
Não convencional em Espanhol | PAHO-IRIS | ID: phr-55544

RESUMO

Esta publicación de la Organización Panamericana de la Salud (OPS) es una versión actualizada del documento de junio del 2020 titulado Consideraciones sobre la ejecución y el manejo del rastreo de contactos para la enfermedad por coronavirus del 2019 (COVID-19) en la Región de las Américas, cuyo propósito es complementar las orientaciones provisionales proporcionadas por la Organización Mundial de la Salud (OMS) sobre el rastreo de contactos en el contexto de la COVID-19. La presente publicación incluye orientación sobre el rastreo de contactos en los contactos vacunados y viajeros internacionales, así como en los entornos en los que hay transmisión comunitaria. También incluye las definiciones actualizadas de “caso”, “contacto” y “transmisión comunitaria” que ha publicado la OMS. El objetivo del presente documento es brindar orientación y recomendaciones operativas que permitan realizar el rastreo de contactos de COVID-19 en la Región de las Américas. El documento se actualizará conforme se disponga de información nueva sobre la COVID-19. Esta publicación está dirigida a las autoridades nacionales de salud, los profesionales de la salud pública y otros funcionarios que formulan y ejecutan políticas y procedimientos normalizados de trabajo relacionados con las operaciones de rastreo de contactos en la Región.


Assuntos
COVID-19 , Coronavirus , Betacoronavirus , Infecções por Coronavirus , Busca de Comunicante , Vacinas contra COVID-19 , Microscopia Eletrônica de Transmissão e Varredura , Transmissão de Doença Infecciosa , Período de Transmissibilidade , Vacinação , Vacinas , Doenças Preveníveis por Vacina
3.
J Obstet Gynaecol ; : 1-4, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996339

RESUMO

We describe the prevalence of overall and asymptomatic SARS-CoV-2 infection in pregnant women admitted for delivery at three maternity units in North Wales. This was a prospective, multicentre cohort study of universal testing for SARS-CoV-2 infection offered to all pregnant women admitted for delivery. Four hundred and seventy-five women were tested by reverse transcription-polymerase chain reaction of nasopharyngeal swabs with concurrent universal screening for signs and symptoms of COVID-19 infection. The overall prevalence of SARS-CoV-2 infection in pregnant women in North Wales was 2.74% with an asymptomatic prevalence of 1.89%. Sixty-nine percent of infected women were asymptomatic. Pregnant women with SARS-CoV-2 infection are not reliably identified using symptom and temperature screening. The prevalence of maternal infection and asymptomatic carrier rates vary within small geographical regions. It is suggested that a trial period of universal testing may help determine whether such an approach is appropriate for an individual maternity unit.Impact StatementWhat is already known on this subject? The mean incubation period for SARS-CoV-2 is five days and viral shedding may begin two to three days before the appearance of symptoms. Asymptomatic carriers contribute to transmission of the disease.What do the results of this study add? More than two-thirds of infected women were asymptomatic in this study contributing to the body of evidence that most infected pregnant women are asymptomatic. This study provides prevalence data for a rural geographical location in Wales with results similar to an urban London region. There was wide variation in prevalence across three maternity units in a small geographical area ranging from 1.68% to 4.43%.What are the implications of these findings for clinical practice and/or further research? This study supports the recommendations of universal SARS-CoV-2 testing for women attending for delivery regardless of symptom status. The results highlight that prevalence of infection amongst pregnant women cannot be assumed based on geographical location or demographics. A trial period of universal testing would establish local prevalence and helps determine whether such an approach is appropriate for an individual maternity unit. Future research could be directed to the prevalence of virus variants in pregnant populations.

4.
Arab J Sci Eng ; : 1-24, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35018276

RESUMO

The entire world has been affected by the outbreak of COVID-19 since early 2020. Human carriers are largely the spreaders of this new disease, and it spreads much faster compared to previously identified coronaviruses and other flu viruses. Although vaccines have been invented and released, it will still be a challenge to overcome this disease. To save lives, it is important to better understand how the virus is transmitted from one host to another and how future areas of infection can be predicted. Recently, the second wave of infection has hit multiple countries, and governments have implemented necessary measures to tackle the spread of the virus. We investigated the three phases of COVID-19 research through a selected list of mathematical modeling articles. To take the necessary measures, it is important to understand the transmission dynamics of the disease, and mathematical modeling has been considered a proven technique in predicting such dynamics. To this end, this paper summarizes all the available mathematical models that have been used in predicting the transmission of COVID-19. A total of nine mathematical models have been thoroughly reviewed and characterized in this work, so as to understand the intrinsic properties of each model in predicting disease transmission dynamics. The application of these nine models in predicting COVID-19 transmission dynamics is presented with a case study, along with detailed comparisons of these models. Toward the end of the paper, key behavioral properties of each model, relevant challenges and future directions are discussed.

5.
Infect Dis Model ; 7(1): 212-230, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35018310

RESUMO

Classical epidemiological models assume mass action. However, this assumption is violated when interactions are not random. With the recent COVID-19 pandemic, and resulting shelter in place social distancing directives, mass action models must be modified to account for limited social interactions. In this paper we apply a pairwise network model with moment closure to study the early transmission of COVID-19 in New York and San Francisco and to investigate the factors determining the severity and duration of outbreak in these two cities. In particular, we consider the role of population density, transmission rates and social distancing on the disease dynamics and outcomes. Sensitivity analysis shows that there is a strongly negative correlation between the clustering coefficient in the pairwise model and the basic reproduction number and the effective reproduction number. The shelter in place policy makes the clustering coefficient increase thereby reducing the basic reproduction number and the effective reproduction number. By switching population densities in New York and San Francisco we demonstrate how the outbreak would progress if New York had the same density as San Francisco and vice-versa. The results underscore the crucial role that population density has in the epidemic outcomes. We also show that under the assumption of no further changes in policy or transmission dynamics not lifting the shelter in place policy would have little effect on final outbreak size in New York, but would reduce the final size in San Francisco by 97%.

6.
PLoS Comput Biol ; 18(1): e1009780, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35020731

RESUMO

Although system dynamics [SD] and agent-based modelling [ABM] have individually served as effective tools to understand the Covid-19 dynamics, combining these methods in a hybrid simulation model can help address Covid-19 questions and study systems and settings that are difficult to study with a single approach. To examine the spread and outbreak of Covid-19 across multiple care homes via bank/agency staff and evaluate the effectiveness of interventions targeting this group, we develop an integrated hybrid simulation model combining the advantages of SD and ABM. We also demonstrate how we use several approaches adapted from both SD and ABM practices to build confidence in this model in response to the lack of systematic approaches to validate hybrid models. Our modelling results show that the risk of infection for residents in care homes using bank/agency staff was significantly higher than those not using bank/agency staff (Relative risk [RR] 2.65, 95% CI 2.57-2.72). Bank/agency staff working across several care homes had a higher risk of infection compared with permanent staff working in a single care home (RR 1.55, 95%CI 1.52-1.58). The RR of infection for residents is negatively correlated to bank/agency staff's adherence to weekly PCR testing. Within a network of heterogeneous care homes, using bank/agency staff had the most impact on care homes with lower intra-facility transmission risks, higher staff-to-resident ratio, and smaller size. Forming bubbles of care homes had no or limited impact on the spread of Covid-19. This modelling study has implications for policy makers considering developing effective interventions targeting staff working across care homes during the ongoing and future pandemics.

7.
N Engl J Med ; 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986294

RESUMO

BACKGROUND: Before the emergence of the B.1.617.2 (delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), vaccination reduced transmission of SARS-CoV-2 from vaccinated persons who became infected, potentially by reducing viral loads. Although vaccination still lowers the risk of infection, similar viral loads in vaccinated and unvaccinated persons who are infected with the delta variant call into question the degree to which vaccination prevents transmission. METHODS: We used contact-testing data from England to perform a retrospective observational cohort study involving adult contacts of SARS-CoV-2-infected adult index patients. We used multivariable Poisson regression to investigate associations between transmission and the vaccination status of index patients and contacts and to determine how these associations varied with the B.1.1.7 (alpha) and delta variants and time since the second vaccination. RESULTS: Among 146,243 tested contacts of 108,498 index patients, 54,667 (37%) had positive SARS-CoV-2 polymerase-chain-reaction (PCR) tests. In vaccinated index patients who became infected with the alpha variant, two vaccinations with either BNT162b2 or ChAdOx1 nCoV-19 (also known as AZD1222), as compared with no vaccination, were independently associated with reduced PCR positivity in contacts (adjusted rate ratio with BNT162b2, 0.32; 95% confidence interval [CI], 0.21 to 0.48; and with ChAdOx1 nCoV-19, 0.48; 95% CI, 0.30 to 0.78). Vaccine-associated reductions in transmission of the delta variant were smaller than those with the alpha variant, and reductions in transmission of the delta variant after two BNT162b2 vaccinations were greater (adjusted rate ratio for the comparison with no vaccination, 0.50; 95% CI, 0.39 to 0.65) than after two ChAdOx1 vaccinations (adjusted rate ratio, 0.76; 95% CI, 0.70 to 0.82). Variation in cycle-threshold (Ct) values (indicative of viral load) in index patients explained 7 to 23% of vaccine-associated reductions in transmission of the two variants. The reductions in transmission of the delta variant declined over time after the second vaccination, reaching levels that were similar to those in unvaccinated persons by 12 weeks in index patients who had received ChAdOx1 nCoV-19 and attenuating substantially in those who had received BNT162b2. Protection in contacts also declined in the 3-month period after the second vaccination. CONCLUSIONS: Vaccination was associated with a smaller reduction in transmission of the delta variant than of the alpha variant, and the effects of vaccination decreased over time. PCR Ct values at diagnosis of the index patient only partially explained decreased transmission. (Funded by the U.K. Government Department of Health and Social Care and others.).

9.
Clin Infect Dis ; 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34984442

RESUMO

This retrospective study of incoming travelers with COVID-19 showed that individuals immunized by mRNA vaccines had significantly longer post-vaccination interval (median: 30.5 days) to breakthrough infection, lower WBC and LDH on admission, and less radiographic abnormalities than those immunized by inactivated virus vaccine who paradoxically had lower respiratory viral load.

10.
J Healthc Eng ; 2022: 6701364, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35003573

RESUMO

To provide a basic quantitative mathematical model for data analysis, decision-making support, and application of information systems oriented to emergency research, this paper established an information transmission response model for school students under such system mathematically based on actual school information transmission data during COVID-19 prevention. This paper proposes an emergency information management method-a two-step emergency information management method. It can be referenced for promotion of the development of IT-based school management, enhancement of IT application in school emergency information management, and improvement of the speed and accuracy of information transmission.


Assuntos
COVID-19 , Saúde Pública , COVID-19/prevenção & controle , Técnicas de Apoio para a Decisão , Emergências , Humanos , Modelos Teóricos , SARS-CoV-2 , Estudantes
11.
J Korean Med Sci ; 37(1): e12, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34981682

RESUMO

BACKGROUND: Despite the extraordinary speed of mass vaccination efforts, an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delta variant in a vaccinee with coronavirus disease 2019 (COVID-19) mRNA vaccine was identified in an adult day service center (ADSC) of Jeju, South Korea. The primary objective of this study was to investigate the epidemiologic features in infection-vulnerable facilities with a high vaccination rate of BNT162b2 mRNA COVID-19 vaccine. The second was to estimate the secondary transmission prevention effect of the vaccine in the household members by vaccination status. METHODS: We included all ADSC participants, staff and their household members. All COVID-19 infected cases were confirmed by reverse transcriptase polymerase chain reaction. We calculated attack rate in ADSC and the secondary attack rate (SAR) in household members by vaccination status. RESULTS: Among a total of 42 participants and 16 staff, of which 96.6% were fully vaccinated with BNT162b2 mRNA COVID-19 vaccine, 12 symptomatic cases and 13 asymptomatic confirmed cases of COVID-19 were found. The attack rate was 43.1%, with 13 isolates identified as SARS-CoV-2 virus, delta variant. The SAR in unvaccinated and partially vaccinated household members were 27.8% (5/18) and 25.0% (5/20), respectively, while the SAR in fully vaccinated household members was 12.5% (1/8). CONCLUSION: We describe a SARS-CoV-2 delta variant outbreak in ADSC with high vaccine coverage rate, characterized by high infection rate, high transmissibility, and low clinical severity. The outbreak proceeded to unvaccinated or partially vaccinated household members, emphasizing the need for immunizing close contacts of high-risk groups.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2 , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/prevenção & controle , COVID-19/transmissão , Vacinas contra COVID-19 , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Vacinação
12.
Euro Surveill ; 27(1)2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34991781

RESUMO

BackgroundCruise ships provide an ideal setting for transmission of SARS-CoV-2, given the socially dense exposure environment.AimTo provide a comprehensive review of COVID-19 outbreaks on cruise ships.MethodsPubMed was searched for COVID-19 cases associated with cruise ships between January and October 2020. A list of cruise ships with COVID-19 was cross-referenced with the United States Centers for Disease Control and Prevention's list of cruise ships associated with a COVID-19 case within 14 days of disembarkation. News articles were also searched for epidemiological information. Narratives of COVID-19 outbreaks on ships with over 100 cases are presented.ResultsSeventy-nine ships and 104 unique voyages were associated with COVID-19 cases before 1 October 2020. Nineteen ships had more than one voyage with a case of COVID-19. The median number of cases per ship was three (interquartile range (IQR): 1-17.8), with two notable outliers: the Diamond Princess and the Ruby Princess, which had 712 and 907 cases, respectively. The median attack rate for COVID-19 was 0.2% (IQR: 0.03-1.5), although this distribution was right-skewed with a mean attack rate of 3.7%; 25.9% (27/104) of voyages had at least one COVID-19-associated death. Outbreaks involving only crew occurred later than outbreaks involving guests and crew.ConclusionsIn the absence of mitigation measures, COVID-19 can spread easily on cruise ships in a susceptible population because of the confined space and high-density contact networks. This environment can create superspreader events and facilitate international spread.


Assuntos
COVID-19 , Navios , Centers for Disease Control and Prevention, U.S. , Surtos de Doenças/prevenção & controle , Humanos , SARS-CoV-2 , Estados Unidos/epidemiologia
13.
J Ultrasound ; 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35000130

RESUMO

PURPOSE: To evaluate the usefulness of compressive ultrasound (CUS) for the diagnosis of deep vein thrombosis (DVT) in patients with SARS-CoV-2-related infection. METHODS: 112 hospitalized patients with confirmed SARS-CoV-2 infection were retrospectively enrolled. CUS was performed within 2 days of admission and consisted in the assessment of the proximal and distal deep venous systems. Lack of compressibility, or direct identification of an endoluminal thrombus, were the criteria used for the diagnosis of DVT. Pulmonary embolism (PE) events were investigated at computed tomography pulmonary angiography (CTPA) within 5 days of follow-up. Logistic binary regression was computed to determine which clinical and radiological parameters were independently associated with PE onset. RESULTS: Overall, the incidence of DVT in our cohort was about 43%. The most common district involved was the left lower limb (68.7%) in comparison with the right one (58.3%) while the upper limbs were less frequently involved (4.2% the right one and 2.1% the left one, respectively). On both sides, the distal tract of the popliteal vein was the most common involved (50% right side and 45.8% left side). The presence of DVT in the distal tract of the right popliteal vein (OR = 2.444 95%CIs 1.084-16.624, p = 0.038), in the distal tract of the left popliteal vein (OR = 4.201 95%CIs 1.484-11.885, p = 0.007), and D-dimer values (OR = 2.122 95%CIs 1.030-5.495, p = 0.003) were independently associated with the onset on PE within 5 days. CONCLUSIONS: CUS should be considered a useful tool to discriminate which category of patients can develop PE within 5 days from admission.

14.
Int J Environ Res ; 16(1): 9, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35013682

RESUMO

Due to the prevalence of the COVID-19 outbreak, as well as findings of SARS-CoV-2 RNA in wastewater and the possibility of viral transmission through wastewater, disinfection is required. As a consequence, based on prior investigations, this work initially employed the viral concentration detection technique, followed by the RT-qPCR assay, as the foundation for identifying the SARS-CoV-2 virus in wastewater. After that, the ability and efficacy of chlorine, ozone, and UV disinfection to inactivate the SARS-CoV-2 virus from wastewater were examined. Chlorine disinfection is the most extensively used disinfection technology due to its multiple advantages. With a chlorine dioxide disinfectant dose of 40 mg/L, the SARS-CoV virus is inactivated after 30 min of contact time. On the other hand, ozone is a powerful oxidizer and an effective microbicide that is employed as a disinfectant due to its positive characteristics. After 30 min of exposure to 1000 ppmv ozone, corona pseudoviruses are reduced by 99%. Another common method of disinfection is using ultraviolet radiation, which is usually 253.7 nm suitable for ultraviolet disinfection. At a dose of 1048 mJ/cm2, UVC radiation completely inactivates the SARS-CoV-2 virus. Finally, to evaluate disinfection performance and optimize disinfection strategies to prevent the spread of SARS-CoV-2, this study attempted to investigate the ability to remove and compare the effectiveness of each disinfectant to inactive the SARS-CoV-2 virus from wastewater, summarize studies, and provide future solutions due to the limited availability of integrated resources in this field and the spread of the SARS-CoV-2 virus worldwide.

15.
Environ Sci Technol ; 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35015513

RESUMO

A simulation model was developed aimed at assisting local public health authorities in exploring strategies for the suppression of SARS-CoV-2 transmission. A mechanistic modeling framework is utilized based on the daily airborne exposure of individuals defined in terms of inhaled viruses. Comparison of model outputs and observed data confirms that the model can generate realistic patterns of secondary cases. In the example investigated, the highest risk of being newly infected was among young adults, males, and people living in large households. Among risky occupations are food preparation and serving, personal care and service, sales, and production-related occupations. Results also show a pattern consistent with superspreading with 70% of initial cases who do not transmit at all while 13.4% of primary cases contribute 80% of secondary cases. The impacts of school closure and masking on the synthetic population are very small, but for students, school closure resulted in more time at home and increased secondary cases among them by over 25%. Requiring masks at schools decreased the case count by 80%. We conclude that the simulator can be useful in exploring local intervention scenarios and provides output useful in assessing the confidence that might be placed on its predictions.

16.
Complement Med Res ; 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35016186

RESUMO

OBJECTIVE: To determine the impact of covid-19 in patients suffering from NCDs in terms of their knowledge, awareness, perception about COVID-19, use of AYUSH immune boosters, and management of chronic condition during the pandemic. METHOD: During the unlock down period (October 2020), a cross-sectional study was conducted in the Krishna and Darjeeling district of Andhra Pradesh and West Bengal, India. 499 individuals suffering from at least one chronic disease were interviewed using a structured questionnaire. Logistic regression was applied to investigate the relationship of socio-demographic characteristics with pandemic-related care challenges, Ayush Immune boosters(AIB). Principal Component Analysis was applied to minimize the dimensionality of factors related to covid care challenges. RESULTS: 499 individuals were surveyed. 91% identified at least three correct covid appropriate behaviour. 92.2% considered the coronavirus to be a potential threat (mean±sd: 5.8±2.6). 44.7% and 55.3% lived with one and 2 or more chronic conditions respectively. Hypertension alone (27.4%) and diabetes with hypertension (33%) were leading presentations. Out of 499, participants, 88.8% had at least one form of AIB. 52% took Ars. alb with other AIB and 40% took Ars. alb. alone. Only 09 participants were infected from Covid-19. CONCLUSION: In the interest of a densely populated country like India, the inclusion of simple and safe AYUSH measures is realistic, ethical and cost-effective. Ayush interventions as Covid-19 prophylactic and treatment as well as Integrative care of chronic illnesses such as NCDs is suggested.

17.
Swiss Med Wkly ; 152: w30133, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-35019196

RESUMO

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 (B1.617.2) and Omicron (B.1.1.529), are characterized by higher viral loads and a lower minimal infective dose compared to the WT. We aimed to describe the resulting distribution of airborne viral emissions and to reassess the risk estimates for public settings given the higher viral load and infectivity. METHOD: We reran the Monte Carlo modelling to estimate viral emissions in the fine aerosol size range using available viral load data. We also updated our tool to simulate indoor airborne transmission of SARS-CoV-2 by including a CO2 calculator and recirculating air cleaning devices. We also assessed the consequences of the lower critical dose on the infection risk in public settings with different protection strategies. RESULTS: Our modelling suggests that a much larger proportion of individuals infected with the new variants are high, very high or super-emitters of airborne viruses: for the WT, one in 1,000 infected was a super-emitter; for Delta one in 30; and for Omicron one in 20 or one in 10, depending on the viral load estimate used. Testing of the effectiveness of protective strategies in view of the lower critical dose suggests that surgical masks are no longer sufficient in most public settings, while correctly fitted FFP2 respirators still provide sufficient protection, except in high aerosol producing situations such as singing or shouting. DISCUSSION: From an aerosol transmission perspective, the shift towards a larger proportion of very high emitting individuals, together with the strongly reduced critical dose, seem to be two important drivers of the aerosol risk, and are likely contributing to the observed rapid spread of the Delta and Omicron variants of concern. Reducing contacts, always wearing well-fitted FFP2 respirators when indoors, using ventilation and other methods to reduce airborne virus concentrations, and avoiding situations with loud voices seem critical to limiting these latest waves of the COVID-19 pandemic.


Assuntos
COVID-19 , Pandemias , Aerossóis , Humanos , SARS-CoV-2 , Carga Viral
18.
Infect Dis Model ; 7(1): 170-183, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34977438

RESUMO

The coronavirus disease that outbreak in 2019 has caused various health issues. According to the WHO, the first positive case was detected in Bangladesh on 7th March 2020, but while writing this paper in June 2021, the total confirmed, recovered, and death cases were 826922, 766266 and 13118, respectively. Due to the emergence of COVID-19 in Bangladesh, the country is facing a major public health crisis. Unfortunately, the country does not have a comprehensive health policy to address this issue. This makes it hard to predict how the pandemic will affect the population. Machine learning techniques can help us detect the disease's spread. To predict the trend, parameters, risks, and to take preventive measure in Bangladesh; this work utilized the Recurrent Neural Networks based Deep Learning methodologies like LongShort-Term Memory. Here, we aim to predict the epidemic's progression for a period of more than a year under various scenarios in Bangladesh. We extracted the data for daily confirmed, recovered, and death cases from March 2020 to August 2021. The obtained Root Mean Square Error (RMSE) values of confirmed, recovered, and death cases indicates that our result is more accurate than other contemporary techniques. This study indicates that the LSTM model could be used effectively in predicting contagious diseases. The obtained results could help in explaining the seriousness of the situation, also mayhelp the authorities to take precautionary steps to control the situation.

19.
Geroscience ; 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34985588

RESUMO

Respiratory transmission of SARS-CoV-2 from one older patient to another by airborne mechanisms in hospital and nursing home settings represents an important health challenge during the COVID-19 pandemic. However, the factors that influence the concentration of respiratory droplets and aerosols that potentially contribute to hospital- and nursing care-associated transmission of SARS-CoV-2 are not well understood. To assess the effect of health care professional (HCP) and patient activity on size and concentration of airborne particles, an optical particle counter was placed (for 24 h) in the head position of an empty bed in the hospital room of a patient admitted from the nursing home with confirmed COVID-19. The type and duration of the activity, as well as the number of HCPs providing patient care, were recorded. Concentration changes associated with specific activities were determined, and airway deposition modeling was performed using these data. Thirty-one activities were recorded, and six representative ones were selected for deposition modeling, including patient's activities (coughing, movements, etc.), diagnostic and therapeutic interventions (e.g., diagnostic tests and drug administration), as well as nursing patient care (e.g., bedding and hygiene). The increase in particle concentration of all sizes was sensitive to the type of activity. Increases in supermicron particle concentration were associated with the number of HCPs (r = 0.66; p < 0.05) and the duration of activity (r = 0.82; p < 0.05), while submicron particles increased with all activities, mainly during the daytime. Based on simulations, the number of particles deposited in unit time was the highest in the acinar region, while deposition density rate (number/cm2/min) was the highest in the upper airways. In conclusion, even short periods of HCP-patient interaction and minimal patient activity in a hospital room or nursing home bedroom may significantly increase the concentration of submicron particles mainly depositing in the acinar regions, while mainly nursing activities increase the concentration of supermicron particles depositing in larger airways of the adjacent bed patient. Our data emphasize the need for effective interventions to limit hospital- and nursing care-associated transmission of SARS-CoV-2 and other respiratory pathogens (including viral pathogens, such as rhinoviruses, respiratory syncytial virus, influenza virus, parainfluenza virus and adenoviruses, and bacterial and fungal pathogens).

20.
JAMA Netw Open ; 5(1): e2142796, 2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-35006245

RESUMO

Importance: The SARS-CoV-2 viral trajectory has not been well characterized in incident infections. These data are needed to inform natural history, prevention practices, and therapeutic development. Objective: To characterize early SARS-CoV-2 viral RNA load (hereafter referred to as viral load) in individuals with incident infections in association with COVID-19 symptom onset and severity. Design, Setting, and Participants: This prospective cohort study was a secondary data analysis of a remotely conducted study that enrolled 829 asymptomatic community-based participants recently exposed (<96 hours) to persons with SARS-CoV-2 from 41 US states from March 31 to August 21, 2020. Two cohorts were studied: (1) participants who were SARS-CoV-2 negative at baseline and tested positive during study follow-up, and (2) participants who had 2 or more positive swabs during follow-up, regardless of the initial (baseline) swab result. Participants collected daily midturbinate swab samples for SARS-CoV-2 RNA detection and maintained symptom diaries for 14 days. Exposure: Laboratory-confirmed SARS-CoV-2 infection. Main Outcomes and Measures: The observed SARS-CoV-2 viral load among incident infections was summarized, and piecewise linear mixed-effects models were used to estimate the characteristics of viral trajectories in association with COVID-19 symptom onset and severity. Results: A total of 97 participants (55 women [57%]; median age, 37 years [IQR, 27-52 years]) developed incident infections during follow-up. Forty-two participants (43%) had viral shedding for 1 day (median peak viral load cycle threshold [Ct] value, 38.5 [95% CI, 38.3-39.0]), 18 (19%) for 2 to 6 days (median Ct value, 36.7 [95% CI, 30.2-38.1]), and 31 (32%) for 7 days or more (median Ct value, 18.3 [95% CI, 17.4-22.0]). The cycle threshold value has an inverse association with viral load. Six participants (6%) had 1 to 6 days of viral shedding with censored duration. The peak mean (SD) viral load was observed on day 3 of shedding (Ct value, 33.8 [95% CI, 31.9-35.6]). Based on the statistical models fitted to 129 participants (60 men [47%]; median age, 38 years [IQR, 25-54 years]) with 2 or more SARS-CoV-2-positive swab samples, persons reporting moderate or severe symptoms tended to have a higher peak mean viral load than those who were asymptomatic (Ct value, 23.3 [95% CI, 22.6-24.0] vs 30.7 [95% CI, 29.8-31.4]). Mild symptoms generally started within 1 day of peak viral load, and moderate or severe symptoms 2 days after peak viral load. All 535 sequenced samples detected the G614 variant (Wuhan strain). Conclusions and Relevance: This cohort study suggests that having incident SARS-CoV-2 G614 infection was associated with a rapid viral load peak followed by slower decay. COVID-19 symptom onset generally coincided with peak viral load, which correlated positively with symptom severity. This longitudinal evaluation of the SARS-CoV-2 G614 with frequent molecular testing serves as a reference for comparing emergent viral lineages to inform clinical trial designs and public health strategies to contain the spread of the virus.


Assuntos
COVID-19/virologia , RNA Viral , SARS-CoV-2 , Índice de Gravidade de Doença , Carga Viral , Eliminação de Partículas Virais , Adulto , COVID-19/complicações , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Testes Sorológicos
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