The severe acute respiratory syndrome (SARS)

Long-term outcomes for epidemic viral pneumonia survivors after discharge from the intensive care unit: a systematic review

OBJECTIVE

To review the long-term outcomes (functional status and psychological sequelae) of survivors of critical illnesses due to epidemic viral pneumonia before the COVID-19 pandemic and to establish a benchmark for comparison of the COVID-19 long-term outcomes.

METHODS

This systematic review of clinical studies reported the long-term outcomes in adults admitted to intensive care units who were diagnosed with viral epidemic pneumonia. An electronic search was performed using databases: MEDLINE®, Web of Science™, LILACS/IBECS, and EMBASE. Additionally, complementary searches were conducted on the reference lists of eligible studies. The quality of the studies was assessed using the Newcastle-Ottawa Scale. The results were grouped into tables and textual descriptions.

RESULTS

The final analysis included 15 studies from a total of 243 studies. This review included 771 patients with Influenza A, Middle East Respiratory Syndrome, and Severe Acute Respiratory Syndrome. It analyzed the quality of life, functionality, lung function, mortality, rate of return to work, rehospitalization, and psychiatric symptoms. The follow-up periods ranged from 1 to 144 months. We found that the quality of life, functional capacity, and pulmonary function were below expected standards.

CONCLUSION

This review revealed great heterogeneity between studies attributed to different scales, follow-up time points, and methodologies. However, this systematic review identified negative long-term effects on patient outcomes. Given the possibility of future pandemics, it is essential to identify the long-term effects of viral pneumonia outbreaks. This review was not funded. Prospero database registration: (www.crd.york.ac.uk/prospero) under registration ID CRD42021190296.

SARS-CoV-2 and COVID-19: A Narrative Review

The World Health Organisation has reported that the viral disease known as COVID-19, caused by SARS-CoV-2, is the leading cause of death by a single infectious agent. This narrative review examines certain components of the pandemic: its origins, early clinical data, global and UK-focussed epidemiology, vaccination, variants, and long COVID.

Antisense technology as a potential strategy for the treatment of coronaviruses infection: With focus on COVID-19

After the outbreak of coronavirus disease 2019 (COVID-19) in December 2019 and the increasing number of SARS-CoV-2 infections all over the world, researchers are struggling to investigate effective therapeutic strategies for the treatment of this infection. Targeting viral small molecules that are involved in the process of infection is a promising strategy. Since many host factors are also used by SARS-CoV-2 during various stages of infection, down-regulating or silencing these factors can serve as an effective therapeutic tool. Several nucleic acid-based technologies including short interfering RNAs, antisense oligonucleotides, aptamers, DNAzymes, and ribozymes have been suggested for the control of SARS-CoV-2 as well as other respiratory viruses. The antisense technology also plays an indispensable role in the treatment of many other diseases including cancer, influenza, and acquired immunodeficiency syndrome. In this review, we summarised the potential applications of antisense technology for the treatment of coronaviruses and specifically COVID-19 infection.

Can the coronavirus infection penetrates the brain resulting in sudden anosmia followed by severe neurological disorders?

Serious of unpredictable drawbacks of Coronavirus 2019 (COVID-19) infectious disease caused by SARS-COV-2 on the nervous system, have been widely noticed among the huge number of infected people. It was found that this type of newly revolving pandemic infection mainly infects the human respiratory tract causing mild to moderate symptoms, however, the hidden door side of COVID-19 is via penetrating the brain, revealing a huge threat especially to elderly people who are more susceptible to its severe side effects and even death to more extent. Almost 80% of COVID-19 patients suffer from severe neurological manifestations including dizziness, headache, unconscious, irritability, dysfunction in smell, and taste accompanied by muscle fatigue. Herein, we are trying to address the direct neuroinvasive pathway of COVID-19 into human brain cells which is mainly through the olfactory route leading to long-term neurological complications. In addition to highlighting the ability of COVID-19 infection to intensify a pre-existing AD to a more prominent severe stage. The other thing to emphasize is whether AD patients with a highly prominent activation of local immune responses are more or less exposed to getting infected with COVID-19. Along with underlying the hypothesis that the susceptibility to COVID-19 infection may lead to a future risk for neurodegenerative diseases including Alzheimer's disease (AD).

The natural viral load profile of patients with pandemic 2009 influenza A(H1N1) and the effect of oseltamivir treatment

BACKGROUND

The natural history of viral shedding from the upper respiratory tract of the new pandemic 2009 influenza A(H1N1) and the effect of oseltamivir treatment were uncertain.

METHODS

A retrospective cohort study involving 145 consecutive patients with specimens positive by reverse transcriptase-polymerase chain reaction for the matrix and new H1 genes was conducted.

RESULTS

The nontreated and oseltamivir-treated patients were comparable in their viral load at presentation, demography, and the presenting symptoms. No correlation was observed between viral load with age and number of symptoms. Viral load of nasopharyngeal aspirate (NPA) was significantly lower in treated than in nontreated patients at day 5 after symptom onset. When oseltamivir was initiated </= 2 days after symptom onset, a greater rate of viral load reduction in NPA of treated patients than that of nontreated patients was observed (-0.638 [95% CI, -0.809 to -0.466] vs -0.409 [95% CI, -0.663 to -0.185] log(10) copies/mL/d post-symptom onset), and the viral load was undetectable at day 6 after oseltamivir initiation, which was 1 day earlier than that of those whose treatment was initiated > 2 days of symptom onset. The viral load was inversely correlated with concomitant absolute lymphocyte count in nontreated patients (Pearson correlation coefficient [r] = -0.687, P = .001) and treated patients (Pearson r = -0.365, P < .001). Resolution of fever was 1.4 days later in nontreated than treated patients (P = .012)

CONCLUSIONS

The natural viral load profile was described. Oral oseltamivir suppresses viral load more effectively when given early in mild cases of pandemic 2009 influenza A(H1N1) infections.

Altered pathogenesis of porcine respiratory coronavirus in pigs due to immunosuppressive effects of dexamethasone: implications for corticosteroid use in treatment of severe acute respiratory syndrome coronavirus

The pathogenesis and optimal treatments for severe acute respiratory syndrome (SARS) are unclear, although corticosteroids were used to reduce lung and systemic inflammation. Because the pulmonary pathology of porcine respiratory coronavirus (PRCV) in pigs resembles SARS, we used PRCV as a model to clarify the effects of the corticosteroid dexamethasone (DEX) on coronavirus (CoV)-induced pneumonia. Conventional weaned pigs (n = 130) in one of four groups (PRCV/phosphate-buffered saline [PBS] [n = 41], PRCV/DEX [n = 41], mock/PBS [n = 23], and mock/DEX [n = 25]) were inoculated intranasally and intratracheally with the ISU-1 strain of PRCV (1 x 10(7) PFU) or cell culture medium. DEX was administered (once daily, 2 mg/kg of body weight/day, intramuscularly) from postinoculation day (PID) 1 to 6. In PRCV/DEX pigs, significantly milder pneumonia, fewer PRCV-positive cells, and lower viral RNA titers were present in lungs early at PID 2; however, at PID 4, 10, and 21, severe bronchointerstitial pneumonia, significantly higher numbers of PRCV-positive cells, and higher viral RNA titers were observed compared to results for PRCV/PBS pigs. Significantly lower numbers of CD2(+), CD3(+), CD4(+), and CD8(+) T cells were also observed in lungs of PRCV/DEX pigs than in those of PRCV/PBS pigs at PID 8 and 10, coincident with fewer gamma interferon (IFN-gamma)-secreting cells in the tracheobronchial lymph nodes as determined by enzyme-linked immunospot assay. Our results confirm that DEX treatment alleviates PRCV pneumonia early (PID 2) in the infection but continued use through PID 6 exacerbates later stages of infection (PID 4, 10, and 21), possibly by decreasing cellular immune responses in the lungs (IFN-gamma-secreting T cells), thereby creating an environment for more-extensive viral replication. These data have potential implications for corticosteroid use with SARS-CoV patients and suggest a precaution against prolonged use based on their unproven efficacy in humans, including possible detrimental secondary effects.

Bioaerosol sampling for the detection of aerosolized influenza virus

BACKGROUND

Influenza virus was used to characterize the efficacy of a cyclone-based, two-stage personal bioaerosol sampler for the collection and size fractionation of aerosolized viral particles.

METHODS

A Collison single-jet nebulizer was used to aerosolize the attenuated FluMist vaccine into a calm-air settling chamber. Viral particles were captured with bioaerosol samplers that utilize 2 microcentrifuge tubes to collect airborne particulates. The first tube (T1) collects particles greater than 1.8 microm in diameter, while the second tube (T2) collects particles between 1.0 and 1.8 microm, and the back-up filter (F) collects submicron particles. Following aerosolization, quantitative PCR was used to detect and quantify H1N1 and H3N2 influenza strains.

RESULTS

Based on qPCR results, we demonstrate that aerosolized viral particles were efficiently collected and separated according to aerodynamic size using the two-stage bioaerosol sampler. Most viral particles were collected in T2 (1-1.8 microm) and on the back-up filter (< 1 microm) of the bioaerosol sampler. Furthermore, we found that the detection of viral particles with the two-stage sampler was directly proportional to the collection time. Consequently, viral particle counts were significantly greater at 40 minutes in comparison to 5, 10 and 20 minute aerosol collection points.

CONCLUSIONS

Due to a lack of empirical data, aerosol transmission of influenza is often questioned. Using FluMist, we demonstrated that a newly developed bioaerosol sampler is able to recover and size fractionate aerosolized viral particles. This sampler should be an important tool for studying viral transmission in clinical settings and may significantly contribute towards understanding the modes of influenza virus transmission.

Infectious diseases emerging from Chinese wet-markets: zoonotic origins of severe respiratory viral infections

PURPOSE OF REVIEW

In China, close contacts between humans and food animals have resulted in the transmission of many microbes from animals to humans. The two most notable infectious diseases in recent years are severe acute respiratory syndrome and avian influenza. In this review, these two severe zoonotic viral infections transmitted by the respiratory route, with pandemic potential, are used as models to illustrate the role of Chinese wet-markets in their emergence, amplification and dissemination.

RECENT FINDINGS

Two research groups independently discovered the presence of severe acute respiratory syndrome coronavirus-like viruses in horseshoe bats. An astonishing diversity of coronaviruses was also discovered in different species of bats. For the recent and still ongoing avian influenza H5N1 outbreak that originated in Southeast Asia, from 2003 to 21 April 2006, 204 humans have been infected, with 113 deaths. Most patients had recent direct contacts with poultry.

SUMMARY

In Chinese wet-markets, unique epicenters for transmission of potential viral pathogens, new genes may be acquired or existing genes modified through various mechanisms such as genetic reassortment, recombination and mutation. The wet-markets, at closer proximity to humans, with high viral burden or strains of higher transmission efficiency, facilitate transmission of the viruses to humans.