Effectiveness of AstraZeneca vaccine against SARS-CoV-2 (ChAdox1-S) in reducing in-hospital mortality in individuals with COVID-19 and schizophrenia: A retrospective cohort study.

ChAdOx1-S is a viral vector vaccine developed by AstraZeneca. We aimed to assess the effectiveness of 1 and 2 doses of the ChAdOx1-S vaccine in reducing COVID-19-related in-hospital mortality in individuals with schizophrenia. This is a retrospective cohort study using a nationwide hospital database in Brazil. Individuals diagnosed with COVID-19 and schizophrenia were included in the study. The exposures were 0, 1, and 2 doses of ChAdOx1-S. The outcome of mortality was measured in hazard ratios (HR), calculated using multivariable Cox regression models. The study included 1,929 positive cases of COVID-19 in schizophrenia patients. After adjusting for age, socioeconomic factors, and comorbidities, we observed a significant 55% decrease in the hazard of mortality in the 2-dose vaccination group (HR 0.45, 95% CI: 0.310-0.652) compared to the unvaccinated. Surprisingly, our results did not show any significant reduction in the hazard of mortality in the 1 dose vaccination group (HR 1.278, 95% CI: 0.910-1.795). The effectiveness of two doses of ChAdOx1-S in individuals with schizophrenia aligns with findings from studies on the general population. That one dose was insignificant. Overall, these findings are important for informing public health decisions - prioritizing individuals with schizophrenia for vaccinations and managing acceptance of vaccines.

Global seroprevalence and prevalence of infection of influenza in dogs (Canis familiaris): A systematic review and meta-analysis.

Influenza in dogs holds considerable public health significance due to their close companionship with humans, yet several facets of this phenomenon remain largely unexplored. This study undertook a systematic review and meta-analysis of observational studies to gauge the global seroprevalence of influenza in dogs. We also assessed whether pet dogs exhibited a higher seroprevalence of influenza compared to non-pet dogs, explored seasonal variations in seroprevalence, scrutinised the design and reporting standards of existing studies, and elucidated the geographical distribution of canine influenza virus (cIV). A comprehensive analysis of 97 studies spanning 27 countries revealed that seroprevalence of various influenza strains in dogs consistently registered below 10% and exhibited relative stability over the past decade. Significantly, we noted that seroprevalence of human influenza virus was notably higher in pet dogs compared to their non-pet counterparts, whereas seroprevalence of other influenza strains remained relatively uniform among both categories of dogs. Seasonal variations in seroprevalence of cIV were not observed. In summary, our findings indicated the global circulation of cIV strains H3N2 and H3N8, with other strains primarily confined to China. Given the lack of reported cases of the transmission of cIV from dogs to humans, our findings suggest a higher risk of reverse zoonosis than zoonosis. Finally, we strongly advocate for standardised reporting guidelines to underpin future canine influenza research endeavours.

Effectiveness of oseltamivir in reducing COVID-19-related in-hospital deaths: A pharmacoepidemiological study.

BACKGROUND: Oseltamivir is a low-cost antiviral agent that could support or complement treatment of COVID-19. This study assessed whether oseltamivir is effective in reducing COVID-19-related mortality. METHODS: This retrospective cohort study evaluated real-world data from a nationwide database of hospitalisation due to severe acute respiratory syndrome in Brazil. Propensity score matching was used to mimic a randomised controlled trial with 'oseltamivir' and 'no antivirals at all' as the intervention and control groups, respectively. RESULTS: A total of 21 480 and 268 486 patients admitted between February 2020 and January 2023 were included in the intervention and control groups, respectively. After matching, the odds ratio (OR) for death was 0.901 (95% confidence interval [CI] 0.873-0.930). The OR (95% CI) for death in patients who were admitted to the ICU, and on non-invasive or invasive ventilation was 0.868 (0.821-0.917), 0.935 (0.893-0.980), and 0.883 (0.814-0.958), respectively. CONCLUSIONS: Overall, the use of oseltamivir was associated with an attributable risk reduction of 2.50% (95% CI 1.77-3.29). Similar results were observed in patients who were admitted to the ICU, and on non-invasive or invasive ventilation. Oseltamivir is a low-cost potential antiviral treatment for COVID-19.

Difference in clinical features of SARS-CoV-2 in pediatric patients before and after emergence of P.1.

BACKGROUND: The P.1 variant is a Variant of Concern announced by the WHO. The present work aimed to characterize the clinical features of pediatric patients with SARS-CoV-2 before and after the emergence of P.1. METHODS: This is a cohort study. Data of symptomatic patients younger than 18 years diagnosed with COVID-19 by PCR tests registered in Painel COVID-19 Amazonas were analyzed. RESULTS: A total of 4080 symptomatic pediatric patients were identified in the database between March 2020 and July 2021, of which 1654 were categorized as pre-P.1 and 978 as P.1-dominant cases, based on the prevalence of P.1 of >90% in the North Region, Brazil. Lower case-fatality rate was observed in non-infants infected during the P.1-dominant period (0.9% vs. 2.2%). In general, patients infected during the P.1-dominant period had less fever (70.8% vs. 74.2%) and less lower respiratory tract symptoms (respiratory distress: 11.8% vs. 18.9%, dyspnea: 27.9% vs. 34.5%) yet higher prevalence of neurological symptoms, headache for example (42.8% vs. 5.9%). CONCLUSIONS: The prevalence of symptoms of COVID-19 can differ across different periods of variant dominance. Lower prevalence of fever during the P.1-dominant period may reduce the effectiveness of symptom-based screening in public premises where laboratory diagnostic tests are not available. IMPACT: The prevalence rate of symptoms of SARS-CoV-2 infection can differ among different variants. The present work documents the difference in the clinical features of SARS-CoV-2 in patients aged below 18 years before and after the emergence of P.1, the first study of its kind. Unlike previous studies that focus solely on hospitalized cases, the present work considers both mild and severe cases. While non-infants had a lower fatality rate, lower prevalence of fever associated with the emergence of P.1 may reduce the effectiveness of symptom-based screening in public premises where laboratory diagnostic tests are not available.

Risk for Severe Illness and Death among Pediatric Patients with Down Syndrome Hospitalized for COVID-19, Brazil.

Down syndrome is the most common human chromosomal disorder. Whether Down syndrome is a risk factor for severe COVID-19 outcomes in pediatric patients remains unclear, especially in low-to-middle income countries. We gathered data on patients <18 years of age with SARS-CoV-2 infection from a national registry in Brazil to assess the risk for severe outcomes among patients with Down syndrome. We included data from 14,684 hospitalized patients, 261 of whom had Down syndrome. After adjustments for sociodemographic and medical factors, patients with Down syndrome had 1.8 times higher odds of dying from COVID-19 (odds ratio 1.82, 95% CI 1.22-2.68) and 27% longer recovery times (hazard ratio 0.73, 95% CI 0.61-0.86) than patients without Down syndrome. We found Down syndrome was associated with increased risk for severe illness and death among COVID-19 patients. Guidelines for managing COVID-19 among pediatric patients with Down syndrome could improve outcomes for this population.

Better healthcare can reduce the risk of COVID-19 in-hospital post-partum maternal death: evidence from Brazil.

OBJECTIVE: COVID-19 in post-partum women is commonly overlooked. The present study assessed whether puerperium is an independent risk factor of COVID-19 related in-hospital maternal death and whether fatality is preventable in the Brazilian context. METHODS: We retrospectively studied the clinical data of post-partum/pregnant patients hospitalized with COVID-19 gathered from a national database that registered severe acute respiratory syndromes (SIVEP-Gripe) in Brazil. Logistic regressions were used to examine the associations of in-hospital mortality with obstetric status and with the type of public healthcare provider, adjusting for socio-demographic, epidemiologic, clinical and healthcare-related measures. RESULTS: As of 30 November 2021, 1943 (21%) post-partum and 7446 (79%) pregnant patients of age between 15 and 45 years with COVID-19 that had reached the clinical endpoint (death or discharge) were eligible for inclusion. Case-fatality rates for the two groups were 19.8% and 9.2%, respectively. After the adjustment for covariates, post-partum patients had almost twice the odds of in-hospital mortality compared with pregnant patients. Patients admitted to private (not-for-profit) hospitals, those that had an obstetric centre or those located in metropolitan areas were less likely to succumb to SARS-CoV-2 infection. Those admitted to the Emergency Care Unit had similar mortality risk to those admitted to other public healthcare providers. CONCLUSION: We demonstrated that puerperium was associated with an increased odds of COVID-19-related in-hospital mortality. Only part of the risk can be reduced by quality healthcare such as non-profit private hospitals, those that have an obstetric centre or those located in urban areas.

Is pregnancy a risk factor for in-hospital mortality in reproductive-aged women with SARS-CoV-2 infection? A nationwide retrospective observational cohort study.

OBJECTIVE: To examine the effect of pregnancy on coronavirus disease 2019 (COVID-19) -related in-hospital mortality in women of reproductive age (between 15 and 45 years), with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed with polymerase chain reaction tests, adjusted for factors such as co-infection and intervention that were not considered in existing literature. METHODS: Data gathered from a nationwide database in Brazil were analyzed using multivariate logistic regression and multivariate Cox regression. Adjusted odds ratios and hazard ratios of independent factors associated with in-hospital death were calculated. RESULTS: A total of 97 712 women were included in the study. After the adjustment for sociodemographic factors, epidemiologic characteristics, pre-existing medical conditions, and intervention, pregnant women were found to be associated with lower risk for in-hospital mortality as well as longer survival time compared with non-pregnant women. When covariates of intervention were omitted from the analysis, pregnancy did not appear to be a significant factor associated with mortality. CONCLUSION: With the adjustment for intervention that was shown to be an independent factor associated with mortality, pregnancy appeared to have a favorable effect on SARS-CoV-2 infection. Given the immunosuppressed state of pregnancy, this finding is in line with the hypothetical protective role of a weaker immune response that inhibits the production of proinflammatory cytokine.

The Incubation Period of COVID-19: Current Understanding and Modeling Technique.

This chapter aims to answer the following questions regarding the incubation period of COVID-19. Why is understanding the incubation period of COVID-19 important? How long is the incubation time, and what are the associating factors? How should the incubation period be modeled given the current pandemic situation? Where should we go from here? As a critical epidemiological metric, the incubation period is of public health and clinical importance. While the incubation time of COVID-19 is generally similar to that of SARS and MERS, recent studies identifying factors that impact the incubation period of COVID-19, travel history, for example, only tell part of the story. Therefore, in addition to reviewing current findings, this chapter also explores the modeling technique and future research directions of the incubation period of COVID-19.

Guillain-Barre syndrome should be monitored upon mass vaccination against SARS-CoV-2.

In response to the recent pandemic, vaccines have been developed for large-scale immunization. Despite safety and efficacy verified by health authorities, Guillain-Barre syndrome (GBS) remains a risk of unexpected adverse reactions. Since COVID-19-related GBS cases have largely been reported in Europe, vaccines involving viral genetic materials can potentially trigger GBS, as demonstrated in clinical trials in the Americas. Therefore, medical professionals should be aware of GBS as a potential adverse reaction in SARS-CoV-2 vaccination. Consultation with a neurologist may be needed. Nevertheless, this is not to say that the use of vaccines against SARS-CoV-2 should be suspended and that the association between GBS and the vaccine is confirmed or excluded. The benefits of vaccine still outweigh potential adverse effects.

The younger the milder clinical course of COVID-19: Even in newborns?

BACKGROUND: Milder symptoms were observed in children with COVID-19. However, whether this also holds true for neonates is not known. METHODS: The clinical data of a total of 3213 patients aged 2 years or below, including 749 neonates, in Brazil nationwide were studied. Comparisons were made between neonate and infant patients by conducting statistical tests. RESULTS: Neonates appeared to bear more severe clinical courses. In addition to higher case fatality rates, newborns with COVID-19 had much shorter time from symptom onset to death and longer time from symptom onset to discharge. Dyspnoea, sore throat and cough were more prominent in neonate patients, suggestive of both upper and lower respiratory tract infection, as opposed to upper respiratory tract symptoms mostly observed in children. CONCLUSION: Findings suggested that trained immunity provides a possible explanation because the innate immune system in newborns is not "well-trained" while that in adult tends to hyperactive.

Risk factors for predicting mortality in elderly patients with COVID-19: A review of clinical data in China.

While elderly patients are at high risk of fatality, research concerning COVID-19 has largely been done on clarifying the clinical features. As such, the present work aims to identify risk factors for mortality in elderly patients with COVID-19. Given that single-centre studies are less likely informative as elderly remains a minority in the total Chinese population, the present study reviewed the clinical data of geriatric COVID-19 patients gathered from different sources in the public domain. Based on the data of 154 individuals from 26 provinces, age remained a key mortality risk factor among geriatric patients of different ages. While dyspnoea and chest pain/discomfort were more commonly seen in deceased patients as they represented severe pneumonia, fever was more prominent in surviving patients. This was likely due to the lower baseline body temperature observed in elderly which translated to a lower maximum temperature of fever. However, lowering the threshold temperature for fever is not recommended in surveillance. Instead, baseline body temperature measured on a regular basis should be used to define the threshold temperature for fever. Against mixed results, more research should be done on identifying comorbidities associated with mortality in geriatric patients.

Clinical characteristics of COVID-19 in children: Are they similar to those of SARS?

Although the number of SARS-CoV-2 infections has been rising amid the current pandemic of COVID-19, the low infection rate of SARS-CoV-2 in children has been low. By examining the clinical data available in the public domain, the present work clarifies the clinical presentations in children with COVID-19 in China. Statistical significance tests and adjusted odds ratios estimation were performed on the children (age below 18) and adults (age 18 or above) cohorts in China. SARS-CoV and SARS-CoV-2 shared similar clinical features. Lower respiratory tract infection was less prominent in children as evidenced by the relatively low prevalence in chest pain/discomfort and dyspnea. Similar to SARS, younger children had a less aggressive clinical course, compared with adolescents. While fewer symptoms were observed in children compared to adults, there is not yet sufficient evidence to conclude shorter hospital stay in children.

Clinical features of deaths in the novel coronavirus epidemic in China.

In response to the recent novel coronavirus outbreak originating in Wuhan, Hubei province, China, observations concerning novel coronavirus mortality are of urgent public health importance. The present work presents the first review of the fatal novel coronavirus cases in China. Clinical data of fatal cases published by the Chinese Government were studied. As of 2 February 2020, the clinical data of 46 fatal cases were identified. The case fatality rate was significantly higher in Hubei province than the rest of China. While 67% of all deceased patients were male, gender was unlikely to be associated with mortality. Diabetes was likely to be associated with mortality. There is, however, not yet sufficient evidence to support the association between hypertension and mortality as similar prevalence of hypertension was also observed in the Hubei population.

The difference in the incubation period of 2019 novel coronavirus (SARS-CoV-2) infection between travelers to Hubei and nontravelers: The need for a longer quarantine period.

Data collected from the individual cases reported by the media were used to estimate the distribution of the incubation period of travelers to Hubei versus that of nontravelers. Because a longer and more volatile incubation period has been observed in travelers, the duration of quarantine should be extended to 3 weeks.

A lesson learnt from the emergence of Zika virus: What flaviviruses can trigger Guillain-Barré syndrome?

While Zika virus outbreaks raised the concern about rare viral infections in human, attention should also be paid to other Guillain-Barré syndrome (GBS) inducing viruses. This study aims to search for other flaviviruses likely to be associated with GBS. Amino acid (aa) sequence matching analysis was conducted to identify viruses molecularly similar to the Zika virus and human GBS-related proteins. A systematic review of clinical literature was performed to summarize the clinical findings of the GBS-associated flaviviruses identified in the aa sequence matching analysis. It was found that more than 10 pentapeptides were shared between 9 flaviviruses, Zika virus, and human GBS-related proteins. Twenty-six articles totaling 42 clinical cases were eligible for inclusion in the systematic review concerning the nine flaviviruses identified. While some patients showed signs of encephalitis, 5 out of 42 cases demonstrated typical GBS symptoms. Public health professionals should be aware of other GBS-associated flaviviruses and GBS cases with mild symptoms.