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Quarantine restart: What have we learnt?

This week, international travellers began arriving in Melbourne again, and are re-entering Victoria’s revised hotel quarantine facilities. Numbers have been capped at 800 per week and will increase to 1,120 per week on April 15 provided that key recommendations are addressed – including many relating to ventilation.

Focus on airborne transmission

It has been almost two months since international passenger flights to Melbourne were stopped as a result of outbreaks from hotel quarantine that led to a five-day state lockdown. In the wake of these events, reviews were commissioned into Victoria’s quarantine systems, including detailed ventilation assessments of all hotels. Of particular concern were three cases of transmission where travellers had contracted COVID-19 from guests staying in separate rooms.

The main review was conducted by Deputy Chief Health Officer, Professor Allen Cheng, who was supported by an independent expert panel. The team focused on variants of concern (VoC) – more transmissible variants of COVID-19 that have emerged worldwide – and analysed the extent to which hotel quarantine can reduce the risk of transmission within hotels and out to the community.

The review found that additional controls, including vaccination, engineering (particularly ventilation) and administrative controls should reduce the risk of transmission of SARS-CoV-2 within hotel quarantine and from hotel quarantine to the community. It recommended that ventilation assessments be completed, and a timetable be established to deliver on those actions before international flights resumed.

In parallel to this work, detailed ventilation assessments of every quarantine hotel property were commissioned by COVID-19 Quarantine Victoria (CQV) – the dedicated agency created in November last year to oversee all elements of the quarantine program.

The assessments were conducted room by room by an occupational hygienist physician – described by CQV as an expert in heating ventilation, air conditioning and indoor air quality – and a team of engineers and other specialists.

Eight hotels were given an action plan detailing works to be completed, including rebalancing HVAC systems, sealing windows, and replacing fans. Hotels will only be used again once these works are completed, following further validation by the independent ventilation expert.

CQV is conducting further assessments for six hotels due to interim findings. In some instances, the pressure testing completed indicates a large number of rooms are positively pressured (meaning the air can flow from the room to the corridor), requiring rectification.

According to the government, investigations have confirmed that the most likely cause of two of the in-hotel transmission events was airflow from rooms into the corridor when doors were opened.

Time for a national standard?

Another review into the three transmission events mentioned above was undertaken by Safer Care Victoria (SCV) – the peak state authority for quality and safety improvement in healthcare.

This review found that hotel ventilation systems may need to be upgraded for quarantine purposes. Accordingly, SCV recommended developing and implementing minimum ventilation and engineering standards.

SCV has also recommended that the Department of Health lead discussions for a national ventilation standard.

In a press conference to announce the recommencement of international arrivals, Acting Premier James Merlino said that he had written to Prime Minister Scott Morrison to inform him of Victoria’s capacity to accept travellers, and also to advocate for a national standard for ventilation.

“Victoria is the only jurisdiction that has done this additional work in terms of ventilation,” said Merlino, “so we want to share that and have a nationally consistent approach.”

Best practice for quarantine?

The review conducted by Professor Cheng was also tasked with considering the most effective model for quarantine. It looked at three options: hotel quarantine, a hybrid model of hotel and other types of accommodation (including home quarantine), and purpose-built facilities.

The report acknowledges the limitations of hotel quarantine and the advantages of a purpose-built facility.

“While there are clearly measures that can be taken to increase protections in a hotel environment, there are also limitations on what is feasible in established buildings that were not designed to prevent transmission of infectious diseases,” says the report.

“A purpose-built quarantine facility would facilitate engineered controls that are higher in the hierarchy of controls, that in theory should provide the best protection of staff and guests. This would reduce – although not completely eliminate – the risk of incursion into the community.”

The report notes that a long-term quarantine station may be useful for future pandemics, and may have other uses that could be deployed quickly, such as emergency bushfire accommodation.

As part of the review, a member of the panel behind the report travelled to Darwin to inspect the Howard Springs facility.

“It would be fair to say it’s a place to start,” says Professor Cheng of the facility. “It’s a reference standard rather than a gold standard.” He pointed out that Victoria’s cooler climate would require a slightly different solution. The report goes into detail on other areas where the Howard Springs model could be improved.

The government is continuing to investigate the possibility of a permanent, dedicated facility. According to Merlino, 10 sites have been identified, and this will be narrowed down to one in a business case that will be finalised by the end of April. A decision will then be made about whether to proceed.

One Reply to “Quarantine restart: What have we learnt?

  1. What haven’t we learned is the real question!
    HVAC systems incorporate a filtration system.
    What is the function of a filter?
    How does an air conditioner filter work?

    https://www.google.com/search?q=how+does+a+filter+work+in+an+airconditioner+system&rlz=1C1GCEA_enAU827AU827&oq=how+does+a+filter+work+in+an+airconditioner+system&aqs=chrome..69i57j33i22i29i30.57303j0j7&sourceid=chrome&ie=UTF-8

    The air filter is stationed at the point where air is pulled into the system. It traps air-born particles that get sucked in with the air and keeps them from blocking the blower and clogging up the coils. Clogged coils can’t heat or cool the air passing over them, and they may damage the system.

    How Often Should You Change Your Filters During a Pandemic?
    https://www.priorityrental.com/switch-out-hepa-filter-covid-19/
    Usually, air scrubber filters can be changed about once a month; however, during heightened measures where clean air is a top priority, upgrading your system with a new filter at least once a week is considered a good practice.
    There is still a lot of information we don’t know about COVID-19, but we know that droplets carrying the virus can linger in the air for several hours and have a longer life span depending on the surface they are occupying.
    To err on the side of caution, we decided to get on a Zoom call with one of our manufacturers to understand how often businesses should change out their air filters during this pandemic.
    Pre-Filters Should be Changed Once a Week
    Pre-filters enhance air quality by capturing the larger particles, so it makes sense that these would become dirty quickly. These should be switched out on a weekly basis to ensure the system works effectively and in tandem with the HEPA filter.
    HEPA Filters Should be Changed Almost Bi-Weekly
    HEPA filters focus on the smaller particles and are often the final step in the filtration process. As long as you are maintaining your pre-filter appropriately, the HEPA filter should be switched out every 2-3 weeks.
    It’s important to note that if the unit is moved from one room to another, all of your systems filters should be automatically changed. If not, you may run the risk of contaminating the new area.

    How Long can the Coronavirus Survive on HEPA Filters?
    2020-09-10 by Paddy Robertson
    https://smartairfilters.com/en/blog/coronavirus-survive-purifier-hepa-filter/
    Excerpt
    Bottom Line: How Long can the COVID-19 Coronavirus Survive on HEPA Filters
    The coronavirus, SARS, and influenza A viruses typically die in under 48 hours, across a range of surfaces. A hardy, non-enveloped virus (MS-2 coliphage) was able to survive up to 6 days on HEPA filters. However, the coronavirus – being a non-enveloped virus – is unlikely to last this long. A reasonable estimate for the survival of the coronavirus on HEPA filters is 48 hours, with 72 hours being a conservative number.

    COMMENT
    THE REAL PROBLEM
    Any filter has active viral products being deposited on the filter material 24/7.
    There is no guarantee of viral load on the filters, therefore they must be changed!
    But it is commonly acknowledged the regimes can be compromised because of costs.

    A UVC lamp of the correct nano meter range is the only guaranteed method to stop viruses especially the COVI19 issues
    When a UVC lamp is incorporated into the HVAC system prior to coils and fans these along with filters, any viral contamination is killed.
    Then the filter does what is designed to do capture particles which are now not contaminated thus clean virus free air can be introduced into the HVAC system.

    Everyone in the industry knows but everyone remains silent. WHY?

    This article states windows are sealed, where is the outside fresh air.
    Yes, we know from an incident at the Alfred Hospital Melbourne a person jumped out of an opening window.
    Therefore, appropriate security grills must be installed.
    Re jigging pressures in the HVAC system is dangerous there is still possibilities of contaminated air interacting.

    For the experts? What happens when your finger is pressed into kids plasticine?
    The plasticine around your finger moves upwards and outwards, as your finger is pressed downwards.
    Same thing with varying HVAC system pressures in different interconnecting areas.
    No guarantee to stop spreading the virus.
    When the air within the HVAC is correctly treated the issues are as humanly as possible addressed.

    The proposal I read in this article from so called experts are unprofessional and flawed.

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