Principais motivos de descarte de córneas para transplante na Paraíba: por que o anti-HBc merece atenção?* / Main reasons for discarding corneas for transplant in Paraíba: why does anti-HBc deserve attention?*

RESUMO Objetivo: Identificar o perfil dos doadores de tecidos oculares humanos na área de atuação do Banco de Olhos da Paraíba, destacando o impacto da sorologia positiva para hepatite B no descarte dos tecidos para transplante. Métodos: O estudo é transversal e utilizou dados do Banco de Olhos da Paraíba entre janeiro de 2013 e dezembro de 2022. Dados sobre procedência, idade, sexo, causa do óbito, tempo entre óbito e enucleação, resultados sorológicos e motivo de descarte das córneas dos doadores foram coletados. Resultados: O maior motivo de descarte foi por sorologia positiva (56,5%), sendo positivadas as sorologias positivas para hepatite B e HBsAg em 11,1% e 4,75% dos pacientes, respectivamente. Conclusão: A sorologia positiva para hepatite B como um critério de descarte absoluto é responsável por grande parcela de descartes, apesar da pouca informação sobre suas repercussões e representação de infectividade nos receptores do transplante.

ABSTRACT Objective: To identify the profile of human ocular tissue donors in the area covered by the Eye Bank of Paraíba (PB), highlighting the impact of positive serology for hepatitis B (anti-HBc) in the disposal of tissues for transplantation. Methods: This is a cross-sectional that uses data from the Eye Bank of Paraíba (PB) between January 2013 and December 2022. Data on origin, age, sex, cause of death, time between death and enucleation, serological results, and reason for discarded donor corneas were collected. Results: The main reason for discarding was due to positive serology (56.5%), with positive anti-HBc and HBsAg serology in 11.1% and 4.75% of patients, respectively. Conclusion: Anti-HBc positive serology as an absolute disposal criterion is responsible for great part of disposals, despite little information about its repercussions and representation of infectivity in transplant recipients.

The burden and dynamics of hospital-acquired SARS-CoV-2 in England.

Hospital-based transmission had a dominant role in Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV) epidemics1,2, but large-scale studies of its role in the SARS-CoV-2 pandemic are lacking. Such transmission risks spreading the virus to the most vulnerable individuals and can have wider-scale impacts through hospital-community interactions. Using data from acute hospitals in England, we quantify within-hospital transmission, evaluate likely pathways of spread and factors associated with heightened transmission risk, and explore the wider dynamical consequences. We estimate that between June 2020 and March 2021 between 95,000 and 167,000 inpatients acquired SARS-CoV-2 in hospitals (1% to 2% of all hospital admissions in this period). Analysis of time series data provided evidence that patients who themselves acquired SARS-CoV-2 infection in hospital were the main sources of transmission to other patients. Increased transmission to inpatients was associated with hospitals having fewer single rooms and lower heated volume per bed. Moreover, we show that reducing hospital transmission could substantially enhance the efficiency of punctuated lockdown measures in suppressing community transmission. These findings reveal the previously unrecognized scale of hospital transmission, have direct implications for targeting of hospital control measures and highlight the need to design hospitals better equipped to limit the transmission of future high-consequence pathogens.

Detailed analysis of in-hospital transmission of SARS-CoV-2 using whole genome sequencing.

BACKGROUND: Hospital transmission of SARS-CoV-2 has proved difficult to control, with healthcare-associated infections troublesome throughout. AIM: To understand factors contributing to hospital transmission of infections, which is necessary for containing spread. METHODS: An outbreak of 56 staff and patient cases of COVID-19 over a 31-day period in a tertiary referral unit is presented, with at least a further 29 cases identified outside of the unit and the hospital by whole genome sequencing (WGS). FINDINGS: Transmission is documented from staff to staff, staff to patients, and patients to staff, showing disruption of a tertiary referral service, despite implementation of nationally recommended control measures, superior ventilation, and use of personal protective equipment. There was extensive spread from the index case, despite this patient spending only 10 h bed bound on the ward in strict cubicle isolation and with an initial single target low level (CT = 32) polymerase chain reaction test. CONCLUSION: This investigation highlights how effectively and rapidly SARS-CoV-2 can spread in certain circumstances. It raises questions about infection control measures in place at the time and calls into question the premise that transmissibility can be reliably detected by using lower sensitivity rapid antigen lateral flow tests. We also highlight the value of early intervention in reducing impact as well as the value of WGS in understanding outbreaks.

First importations of SARS-CoV-2 P.1 and P.2 variants from Brazil to Spain and early community transmission / Primeras importaciones de las variantes SARS-CoV-2 P.1 y P.2 de Brasil a Madrid y transmisión comunitaria

Introduction: SARS-CoV-2variants of concern (VOC) have been described in the UK (B.1.1.7), South Africa (B.1.351) and Brazil (P.1). Among them, the most scarce information has been obtained from the P.1 variant and more data on its global presence and about its spreading dynamics are needed.Methods: Whole genome sequencing was performed prospectively on travellers arriving from Brazil and on a random selection of SARS-CoV-2 positive cases from our population.Results: In this study we report the first SARS-CoV-2 P.1 and P.2 variants exported from Brazil to Spain. The case infected with the P.1 variant, who had only stayed in Rio de Janeiro, required hospitalisation. The two P.2 cases remained asymptomatic. A wider distribution for P.1 variant beyond the Brazilian Amazonia should be considered. The exportation of the P.2 variant, carrying the E484K mutation, deserves attention. One month after the first description of P.1 and P.2 importations from Brazil to Madrid, these variants were identified circulating in the community, in cases without a travel history, and involved in household transmissionsConclusion: Whole genome sequencing of SARS-CoV-2 positive travellers arriving from Brazil allowed us to identify the first importations of P.1 and P.2 variants to Spain and their early community transmission.

Introducción: Se han descrito «variantes de preocupación» (VOC) de SARS-CoV-2 en el Reino Unido (B.1.1.7), Sudáfrica (B.1.351) y Brasil (P.1). Entre ellas, se dispone de información más escasa para la variante P.1 y se necesitan más datos sobre su presencia global y sobre su dinámica de expansión.Métodos: Se realizó secuenciación del genoma completo de forma prospectiva de SARS-CoV-2 en viajeros procedentes de Brasil y en una selección aleatoria de casos positivos de SARS-CoV-2 de nuestra población.Resultados: En este estudio reportamos las primeras variantes de SARS-CoV-2 P.1 y P.2 exportadas desde Brasil a España. El caso infectado por la variante P.1, que solo había permanecido en Río de Janeiro, requirió hospitalización. Los 2 casos de la variante P.2 permanecieron asintomáticos. Se debe considerar una distribución más amplia para la variante P.1 más allá de la Amazonía brasileña. La exportación de la variante P.2, que porta la mutación E484K, merece asimismo atención adicional. Un mes después de la primera descripción de las importaciones de P.1 y P.2 de Brasil a Madrid, se identificaron estas variantes circulando en la comunidad, en casos sin antecedentes de viaje, e implicadas en transmisiones domiciliarias.Conclusión: La secuenciación de genoma completo de viajeros positivos para SARS-CoV-2 procedentes de Brasil nos permitió identificar las primeras importaciones de variantes P.1 y P.2 a España y su transmisión comunitaria precoz.

Professional practice for COVID-19 risk reduction among health care workers: A cross-sectional study with matched case-control comparison.

BACKGROUND: Health care workers (HCWs) are particularly exposed to COVID-19 and therefore it is important to study preventive measures in this population. AIM: To investigate socio-demographic factors and professional practice associated with the risk of COVID-19 among HCWs in health establishments in Normandy, France. METHODS: A cross-sectional and 3 case-control studies using bootstrap methods were conducted in order to explore the possible risk factors that lead to SARS-CoV2 transmission within HCWs. Case-control studies focused on risk factors associated with (a) care of COVID-19 patients, (b) care of non COVID-19 patients and (c) contacts between colleagues. PARTICIPANTS: 2,058 respondents, respectively 1,363 (66.2%) and 695 (33.8%) in medical and medico-social establishments, including HCW with and without contact with patients. RESULTS: 301 participants (14.6%) reported having been infected by SARS-CoV2. When caring for COVID-19 patients, HCWs who declared wearing respirators, either for all patient care (ORa 0.39; 95% CI: 0.29-0.51) or only when exposed to aerosol-generating procedures (ORa 0.56; 95% CI: 0.43-0.70), had a lower risk of infection compared with HCWs who declared wearing mainly surgical masks. During care of non COVID-19 patients, wearing mainly a respirator was associated with a higher risk of infection (ORa 1.84; 95% CI: 1.06-3.37). An increased risk was also found for HCWs who changed uniform in workplace changing rooms (ORa 1.93; 95% CI: 1.63-2.29). CONCLUSION: Correct use of PPE adapted to the situation and risk level is essential in protecting HCWs against infection.

Vector microbiota manipulation by host antibodies: the forgotten strategy to develop transmission-blocking vaccines.

Human and animal pathogens that are transmitted by arthropods are a global concern, particularly those vectored by ticks (e.g. Borrelia burgdorferi and tick-borne encephalitis virus) and mosquitoes (e.g. malaria and dengue virus). Breaking the circulation of pathogens in permanent foci by controlling vectors using acaricide-based approaches is threatened by the selection of acaricide resistance in vector populations, poor management practices and relaxing of control measures. Alternative strategies that can reduce vector populations and/or vector-mediated transmission are encouraged worldwide. In recent years, it has become clear that arthropod-associated microbiota are involved in many aspects of host physiology and vector competence, prompting research into vector microbiota manipulation. Here, we review how increased knowledge of microbial ecology and vector-host interactions is driving the emergence of new concepts and tools for vector and pathogen control. We focus on the immune functions of host antibodies taken in the blood meal as they can target pathogens and microbiota bacteria within hematophagous arthropods. Anti-microbiota vaccines are presented as a tool to manipulate the vector microbiota and interfere with the development of pathogens within their vectors. Since the importance of some bacterial taxa for colonization of vector-borne pathogens is well known, the disruption of the vector microbiota by host antibodies opens the possibility to develop novel transmission-blocking vaccines.

Effect of Covid-19 Vaccination on Transmission of Alpha and Delta Variants.

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 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 nCoV-19 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.).

Country-specific optimization strategy for testing through contact tracing can help maintain a low reproduction number ([Formula: see text]) during unlock.

In response to the COVID19 pandemic, many countries have implemented lockdowns in multiple phases to ensure social distancing and quarantining of the infected subjects. Subsequent unlocks to reopen the economies started next waves of infection and imposed an extra burden on quarantine to keep the reproduction number ([Formula: see text]) < 1. However, most countries could not effectively contain the infection spread, suggesting identification of the potential sources weakening the effect of lockdowns could help design better informed lockdown-unlock cycles in the future. Here, through building quantitative epidemic models and analyzing the metadata of 50 countries from across the continents we first found that the estimated value of [Formula: see text], adjusted w.r.t the distribution of medical facilities and virus clades correlates strongly with the testing rates in a country. Since the testing capacity of a country is limited by its medical resources, we investigated if a cost-benefit trade-off can be designed connecting testing rate and extent of unlocking. We present a strategy to optimize this trade-off in a country specific manner by providing a quantitative estimate of testing and quarantine rates required to allow different extents of unlocks while aiming to maintain [Formula: see text]. We further show that a small fraction of superspreaders can dramatically increase the number of infected individuals even during strict lockdowns by strengthening the positive feedback loop driving infection spread. Harnessing the benefit of optimized country-specific testing rates would critically require minimizing the movement of these superspreaders via strict social distancing norms, such that the positive feedback driven switch-like exponential spread phase of infection can be avoided/delayed.

Speech air flow with and without face masks.

Face masks slow exhaled air flow and sequester exhaled particles. There are many types of face masks on the market today, each having widely varying fits, filtering, and air redirection characteristics. While particle filtration and flow resistance from masks has been well studied, their effects on speech air flow has not. We built a schlieren system and recorded speech air flow with 14 different face masks, comparing it to mask-less speech. All of the face masks reduced air flow from speech, but some allowed air flow features to reach further than 40 cm from a speaker's lips and nose within a few seconds, and all the face masks allowed some air to escape above the nose. Evidence from available literature shows that distancing and ventilation in higher-risk indoor environment provide more benefit than wearing a face mask. Our own research shows all the masks we tested provide some additional benefit of restricting air flow from a speaker. However, well-fitted mask specifically designed for the purpose of preventing the spread of disease reduce air flow the most. Future research will study the effects of face masks on speech communication in order to facilitate cost/benefit analysis of mask usage in various environments.

Prioritizing high-contact occupations raises effectiveness of vaccination campaigns.

A twenty-year-old idea from network science is that vaccination campaigns would be more effective if high-contact individuals were preferentially targeted. Implementation is impeded by the ethical and practical problem of differentiating vaccine access based on a personal characteristic that is hard-to-measure and private. Here, we propose the use of occupational category as a proxy for connectedness in a contact network. Using survey data on occupation-specific contact frequencies, we calibrate a model of disease propagation in populations undergoing varying vaccination campaigns. We find that vaccination campaigns that prioritize high-contact occupational groups achieve similar infection levels with half the number of vaccines, while also reducing and delaying peaks. The paper thus identifies a concrete, operational strategy for dramatically improving vaccination efficiency in ongoing pandemics.

Intestinal viral infections of nSARS-CoV2 in the Indian community: Risk of virus spread in India.

In December 2019, novel severe acute respiratory syndrome coronavirus 2 (nSARS-CoV-2) virus outbreaks emerged from Wuhan, China, and spread all over the world, including India. Molecular diagnosis of Coronavirus Disease 2019 (COVID) 19 for densely and highly populated countries like India is time-consuming. A few reports have described the successful diagnosis of nSARS-CoV-2 virus from sewage and wastewater samples contaminated with fecal matter, suggesting the diagnosis of COVID 19 from the same to raise an alarm about the community transmission of virus for implementation of evacuation and lockdown strategies. So far, the association between the detection of virus and its concentration in stool samples with severity of the disease and the presence or absence of gastrointestinal symptoms have been rarely reported. We led the search utilizing multiple databases, specifically PubMed (Medline), EMBASE, and Google Scholar. We conducted a literature survey on gastrointestinal infection and the spread of this virus through fecal-oral transmission. Reports suggested that the existence and persistence of nSARS-CoV-2 in anal/rectal swabs and stool specimens for a longer period of time than in nasopharyngeal swabs provides a strong tenable outcome of gastrointestinal contamination and dissemination of this infection via potential fecal-oral transmission. This review may be helpful to conduct further studies to address the enteric involvement and excretion of nSARS-CoV-2 RNA in feces and control the community spread in both COVID-19 patients ahead of the onset of symptoms and in asymptomatic individuals through wastewater and sewage surveillance as an early indication of infection. The existence of the viral genome and active viral particle actively participate in genomic variations. Hence, we comprehended the enteric spread of different viruses amongst communities with special reference to nSARS-CoV-2.