P057 Virus aerosol propagation by CPAP is proportional to mask leak and can be prevented by use of a hood and air filtration system

Introduction Nosocomial transmission of SARS-CoV-2 has caused significant morbidity/mortality in the COVID-19 pandemic. Because patients auto-emit aerosols containing viable virus, these aerosols can be further propagated when patients undergo certain treatments including continuous positive airway pressure (PAP) therapy. This study aimed to assess the degree of viable virus propagated from mask leak in a PAP circuit. Methods Bacteriophage PhiX174 (108copies/mL) was nebulised into a custom PAP circuit. Mask leak was systematically varied to 0, 7, 21, 28 and 42 L/min at the mask interface. Plates containing Escherichia coli assessed the degree of viable virus settling on surfaces around the room. In order to contain virus spread a ventilated headboard and high efficiency particulate air (HEPA) filter was tested. Results Increasing mask leak was associated with virus contamination in a dose response manner (χ2= 58.24, df=4, p<0.001). Clinically relevant levels of leak (≥21 L/min) were associated with virus counts equivalent to using PAP with a standard vented mask. Viable viruses were recorded on all plates (up to 3.86m from source). A plastic hood with HEPA filtration significantly reduced viable viruses on all plates. HEPA exchange rates of 170 and 470m3/hr eradicated all evidence of virus contamination. Discussion Mask leak from PAP circuits may be a major source of environmental contamination and nosocomial spread of infectious respiratory diseases. Subclinical levels of leak should be treated as an infectious risk. Cheap and low-cost patient hoods with HEPA filtration are an effective countermeasure.

Source Tracking of Chicken Infectious Anemia Virus in a SPF Chicken Population, the Latest Report in China

BackgroundLive attenuated vaccines have been extensively used to prevent infectious disease in poultry flocks. However, exogenous virus contamination in attenuated vaccines had been reported several times in the past, which brought enormous threat to poultry production and diseases prevention and control. Recently, an attenuated vaccine against Newcastle Disease produced in China was detected contamination with chicken infectious anemia virus (CIAV) in a routine inspection for exogenous virus. To understand the multiple routes of transmission of CIAV, and to better formulate correct prevention and control, it is necessary to find out the possible source of this contamination.Methodslood samples of SPF chickens that generated vaccines were collected to investigate CIAV antibody titers by ELISA test. Then, 14- to 18-day-old SPF chicken embryos (n=40) were randomly selected, DNA was extracted and detected by quantitative real-time PCR and nucleic acid dot hybridization assays. To further investigate the molecular features of the CIAV isolate, the complete genome of CIAV was amplified and analyzed.ResultsThe results showed both SPF chickens and embryos for vaccine preparation were CIAV-positive. In addition, the full-length genome sequences of CIAV from vaccines and SPF chicken embryos were consisted of 2,298 nucleotides (nt) with 100% homology, named as SDSPF2020 (Genbank accession number: MW660821). It demonstrated 95.7%-99.6% homology with the complete nucleotide sequences of reference strains, and shared the closest evolution relationship with the Chinese strain HLJ15125. ConclusionThis study illustrated that vertical transmission of CIAV from SPF chickens and embryos was an important way for exogenous virus contamination in vaccine production. As such, vaccine quality monitoring and health control are significant in the poultry industry from an environmental safety point of view.

Development of a Quantitative One-Step RT-PCR Method for the Detection of Sabin 2 Virus Contamination in a Novel Oral Poliovirus Vaccine Type 2

To control circulating vaccine-derived type 2 poliovirus outbreaks, a more genetically stable novel Oral Poliovirus Vaccine type 2 (nOPV2) was developed by targeted modifications of Sabin 2 genome. Since the use of OPV2 made of Sabin 2 strain has been stopped, it is important to exclude the possibility that batches of nOPV2 are contaminated with Sabin 2 virus. Here, we report the development of a simple quantitative one-step reverse-transcription polymerase chain reaction assay for the detection and quantitation of Sabin 2 virus in the presence of overwhelming amounts of nOPV2 strain. The method is specific and linear within 8 log10 range even in the presence of relevant amounts of nOPV2 virus. It is sensitive, with a lower limit of detection of 0.2 CCID50/mL (an equivalent of 198 genome copies per mL), and generates reproducible results. This assay can be used for quality control and lot release of the nOPV2.

Mental Health Issues during Covid-19 Pandemic in Portuguese Prisons

During imprisonment, inmates face many difficulties to adapt to prison life well depicted in either classical works or recent research. They usually face many struggles related to the lack of contact with their families. For instance, the less the number of prison visits, the higher levels of aggressiveness and, consequently, the lower levels of adaptation. Additionally, this population is already problematic in “normal conditions” of their imprisonment. When facing crisis – such as the Covid-19 pandemic – their mental and emotional conditions become even worst. Inmates may experience higher levels of anxiety and stress due to the uncertain and high-risk circumstances they are all living. In addition, the deprivations of the support from their families, combined with the higher risk they are exposed due to the danger of Covid-19 virus’ contamination, substantially increase their concerns and could contribute to their lack of adjustment. The present chapter refers to the policies implemented by the Portuguese Prison Administration to deal with the Covid-19 pandemic and a provisional balance of its effects after one year of implementation. Besides information regarding inmate’s mental health conditions during pandemic, data on recidivism rates and criminal activity will also be discussed concerning their implication for future penitentiary policies.