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covid19_victoria

Covid-19 in Victoria

Introduction

  • population 6.4 million
    • 4.5 million live in Greater Melbourne
      • Western Health with Werribee Mercy services:
        • 255,000 in City of Wyndham
        • 209,000 in City of Brimbank
        • 157,000 in City of Melton
        • 97,000 in City of Hobsons Bay
        • 91,000 in City of Maribyrnong
        • plus NW regions such as Sunbury, Gisborne
        • by comparison, the population of the whole of Tasmania is 522,000
    • 188,000 live in Geelong
    • 104,000 live in Ballarat
    • 94,000 live in Bendigo
  • pre-Covid19 healthcare capacity
    • Victoria has very limited ICU capacity with only 476 ICU beds, much fewer per capita than NSW, Italy and far fewer than Japan and South Korea, but the Victorian govt is planning to at least double capacity and hopes to secure 2000 ventilators from overseas and may consider converting the Melbourne Convention and Exhibition Centre into a makeshift intensive care hospital and morgue 1)
    • Doubling the number of ICU beds means finding another 10,000 intensive care nurses if one wishes to maintain a 1:1 patient to nurse ratio. In reality, when it comes to this the system will operate in crisis mode and nurse ratios may need to be changed and standard of care reduced.
    • in March 2020, the Vic. Premier announced it will create and additional 4000 ICU beds to bring the capacity to 4500. The Victorian government will spend $1.2 billion on buying machines and personal protective equipment for healthcare professionals. A further $65 million will be spent on capital works and upskilling the health workforce.2) Unfortunately, it is hard to see how the number of ventilators, accessories and critical care enabled staffing could practically be uplifted to support anywhere near this level given global demands.
      • in May 2020, the proposal for a 750-bed intensive care unit at Melbourne Convention and Exhibition Centre was shelved when it seemed Victoria had brought Covid under control.
  • Aged Care facilities
    • over 50,000 residents in Aged care facilities in Greater Melbourne with most of these in private facilities with funding and oversight by the Federal Govt not the State Govt

Covid-19 timeline

the "1st wave" - repatriated travelers and small local outbreaks brought under control

  • 1st March: 9th case in Victoria; DHHS starts to drive hospitals to increase capacity, use telehealth3) and consider introduction of fever clinics when testing demand ramps up.
  • 11th March 2020: WHO declares it a pandemic
  • 14th March: 1st Victorian case to have been acquired in Australia without a known local contact with an overseas traveler
  • 19th March: mass gatherings of more than 100 people indoors and 500 outdoors banned in Australia, resulting in sports being played without crowds, tourist destinations such as The Twelve Apostles Visitor Centre, the 1000 steps, Werribee mansion and Buchan Caves closed.
  • 20th March: Australia bans entry of all non-residents and residents arriving will have to self-isolate for 14 days
  • 21st March: Stage 1 restrictions introduced
  • 24th March: WA, SA and NT close borders to eastern states
  • 24th March: Vic and NSW Stage 2 lock down - only essential services open, while schools and non-essential retail, gyms, etc to close
  • 28th March 2020: 1st Covid-19 patient to die at Western Health, 2 others intubated in ICU
  • 29th March: all residents arriving in Australia enforced quarantine in hotels on arrival for 14 days
  • 30th March: Stage 3 social distancing restrictions put in place - no more than 2 people together outside; beaches, outside gyms and playgrounds closed;
  • 31st March: 917 confirmed cases of which only 37 have been acquired in Australia without a known local contact with an overseas traveler (536 from OS travel and 281 local contacts of these travelers, and most cases are those in their 20's and live in CBD, inner eastern suburbs and Mornington Peninsula); 4 deaths; over 45,000 tested;
  • 1st April: massive funding boost for ICU beds as the number of confirmed coronavirus cases rose by 51 overnight, bringing the state's total to 968. The Health Department believes 39 people acquired the disease through community transmission. 32 people in hospital, including six in intensive care, and 343 people have recovered.
  • 22nd April: minimal community transmission evident; Reff estimated to be 0.5 due to the strict social distancing laws4); re-introduction of some elective surgery, particularly cat 1 priority cases;
  • 24th April: notification of a small outbreak with 16 positive cases at Albert Road Clinic, a private mental health facility in Melbourne
  • 30th April: four residents and one worker tested positive in Hawthorn Grange aged care facility
  • 1st May: voluntary screening of asymptomatic HCWs begins and plans to screen 100,000 people in next 2 weeks to ascertain degree of community spread
  • 2nd May: notification of 8 employees at a meat processing plant testing positive after one had presented to hospital with initially asymptomatic disease. Facility was closed for further cleaning and contact tracing.
  • 7th May: 62 cases now connected with the Cedar meat processing plant 5) as HCW's at two aged care facilities test positive - Bacchus Marsh and Footscray. Victoria's known active cases rise to 114.
  • 9th May: 76 cases now connected with the Cedar meat processing plant outbreak;
  • 11th May: Premier announces easing of restrictions starting 13th May - 5 family/friend visitors indoors and 10 outdoors; Can now go hiking, golf, fishing but no overnight stays including camping, hotels or AirBnB; Cafes still restricted to take aways only; Communal outdoor gyms and playgrounds remain closed; 6)
  • 14th May: new outbreak amongst workers at MacDonald's Restaurant in Fawkner
  • 17th May: Premier announced further easing of restrictions as of 1st June with cafes and restaurants allowed to re-open with max. 20 patrons per enclosed space which will increase to 50 by June 22 and 100 from mid-July but public bars will remain closed only the bistros can open, and restaurants will be required to keep contact details of all patrons and comply with a range of rules. Cedar Meats outbreak now at 100.
  • 20th May: re-fit of the former Peter MacCallum Cancer Centre in East Melbourne is completed costing $30m and establishing 84 beds over eight floors in readiness for Covid surge

"the 2nd wave" - uncontrolled community spread, contact tracing resources rapidly overwhelmed

  • 26th May (“day 0”): 1st security officer involved in hotel quarantines to become +ve goes largely unnoticed but in retrospect is the start of the second wave.7)
  • 9th June: only 6 new cases in past 4 days as previous known outbreaks are under control - the calm before the storm!
  • 17th June: highest daily infections in past month as 21 new cases recorded, although 15 are in returned travelers
  • 24th June: a further 20 new cases in a day sees R rising to 2.5 creating major concern; Victoria has requested logistical support from the Australian Defence Force and help from other states as it tries to tackle an increasing number of coronavirus infections in the community; Commence door-to-door testing of high prevalence suburbs including Keilor Downs, Sunshine West, Brunswick West, Hallam.
  • 29th June: daily new cases hit 75; Outbreak appears to stem from security staff employed to enforce hotel quarantine of returned travelers failed to ensure quarantine and claims have been made that they not only allowed some to go shopping but had sex with some of them - genomic analysis seems to confirm the hotel quarantine as the source of the outbreak which is causing the highest level of community transmission in Victoria to date.

Stage 3 restrictions introduced

  • 30th June: Premier announces 10 individual suburb lockdowns for next 4 weeks, occupants must have a valid reason for leaving the house - post codes and details here
  • 1st July: 73 cases;
  • 2nd July: 77 cases;
  • 3rd July: 66 cases;
  • 4th July: 108 new cases past day with 23 from high rise towers in Kensington and Nth Melb, 9 of which have been fully locked down while testing and cleaning is performed. Flemington and Kensington are added to the lock down suburbs.
  • 5th July: 74 cases;
  • 6th July: daily cases jump to 127 bringing the towers outbreak to 53 as Premier announces the NSW-Vic border to be closed on the 8th July.
  • 7th July: 191 more cases and the Premier announces a return to Stage 3 Restrictions for whole of Melbourne and Shire of Mitchell for the next 6 weeks and you now can't leave metropolitan Melbourne to get your daily exercise.
  • 8th July: 134 cases;
  • 9th July: 20 health care workers test +ve impacting Northern Hospital ED in particular; Victoria hits 1 millionth test and now 0.4% +ve, 7% of the +ves are asymptomatic; risk-balanced partial reductions in elective surgery re-introduced to provide capacity;
  • 10th July: 288 new cases past day, only 26 linked to known outbreaks; active cases exceed 1000 for 1st time; Govt requests wearing of masks in public;
  • 11th July: 216 new cases, 1 death;
  • 12th July: 1 death, 273 new cases brings active cases to 1484 in more than 100 active outbreaks; 138 cases linked to the high rise towers which have a cross-over with the 134 cases linked to Al-Taqwa College; 28 new cases in Carlton high rise towers; several Aged Care facilities now have outbreaks; 16 cases in ICU; 8 HCWs at Alfred Hosp test +ve as well as 11 at Brunswick Private; new outbreak in Somerville Meats meatworks in Tottenham as well as JBS Meats abbatoir; Schools to remain closed (excl. year 11 and 12) after the school holiday break ends today;
  • 13th July: 177 cases;
  • 14th July: 270 cases, 2 deaths;
  • 15th July: 238 cases, 1 death;
  • 16th July: 317 new cases; over 150 cases in HCWs; 32 pts in ICU; 2 deaths;
  • 17th July: 428 new cases; 122 in hospital; 3 deaths;
  • 18th July: 217 cases; 3 deaths;
  • 19th July: 363 cases; 3 deaths; wearing masks in public to become mandatory on 23rd July. R0 apparently is 1.3.
  • 20th July: 275 cases, 1 death;
  • 21t July: 374 cases, 3 deaths;
  • 22nd July: 484 new cases; over 300 cases now in Aged Care;
  • 23rd July: 403 new cases, 13 in regional victoria; 201 in hospital, 40 in ICU; deaths now at 49 after 5 deaths in 24hrs;
  • 24th July: 300 new cases; 3734 active cases; 7 more deaths;
  • 25th July: 357 cases; 5 deaths;
  • 26th July: 459 new cases; 4233 active cases incl.381 HCWs; 10 more deaths; 228 in hospital; 42 in ICU; 1.5 million tests done; 8191 total cases (0.5% of all tests);
  • 27th July: 532 new cases; 6 more deaths to total 77 and 161 deaths Australia-wide; 683 active Aged care sector cases; this “second wave” mainly driven now by workers in aged care, distribution centres, meatworks, cool stores and warehouses exacerbated by the pre-existing casualisation of the workforce and concerns over lost income and presenteeism if don't go to work with mild symptoms;
  • 28th July: 384 new cases; 6 more deaths; 20% of Aged care facilities affected with 764 active cases across private residential aged care facilities, 100 residents have been moved to hospitals; 400 active cases in HCWs; all non-urgent elective surgery halted
  • 29th July: 295 new cases; 9 more deaths; 4839 active; 92 deaths in total;
  • 30th July: 723 new cases; 13 more deaths; 312 in hospital; 34 in ICU; 5835 active cases incl. 255 in regional Vic.; new restrictions for regional Victoria - Geelong-Colac areas. Masks to become mandatory in all of Victoria as of 3rd Aug and this intervention is expected to reduce R0 by 15%.
  • 31st July: 627 new cases;8 deaths; 928 active cases with 61 deaths in Aged Care facilities - only 5 cases are in a public run facility with mandated nurse ratios and less casualisation of nurses although public makes up only 10% of beds and these are mainly in regional Victoria. 2 doctors are now in ICU - an ED registrar and a GP.
  • 1st Aug: 397 new cases; 3 deaths; 5919 active cases of which 1008 in Aged Care and 311 from the housing tower blocks; 379 in hosp; 41 in ICU; 637 active HCW cases (1075 total)

Stage 4 restrictions introduced and State of Disaster enacted

  • 2nd Aug: 671 new cases; total to date now 11,557; 7 deaths; 6322 active cases incl. 649 HCWs; 385 in hospital; 38 in ICU; Premier announces State of Disaster and Stage 4 restrictions including 8pm-5am curfew and exercise and shopping restricted to within 5km of home, schools, non-essential retail and most industries are closed while others are reduced
  • 3rd Aug: 429 new cases; 13 deaths (8 from Aged Care) taking deaths to 136; 6489 active; 416 in hospital, 45 in ICU;
  • 4th Aug: 439 new cases; total 12,335 with 6706 active incl. 731 HCWs and 1186 in Aged care; 11 deaths taking tally to 147; 456 in hospital; 38 in ICU;
  • 5th Aug: 725 new cases; 15 deaths incl. a man in his 30's; 538 in hospital; 42 in ICU; 7227 active cases incl. 1435 in Aged Care;
  • 6th Aug: 471 new cases; 8 deaths;
  • 7th Aug: 450 new cases; 11 deaths; 7637 active incl. 911 HCWs 1548 in aged care; 607 in hospital, 41 in ICU;
  • 8th Aug: 466 new cases; 12 deaths incl. a man in his 30's; 636 in hospital, 44 in ICU; “Premier states there are adequate supplies of PPE” R0 appears to have dropped to 0.9;

Predictive modelling

  • epidemic calculators:
    • day 0 is mid-Feb 2020, day 150 is thus mid-July
    • the timing of the peak is very sensitive to the duration a patient is likely to be infectious or the incubation period, and less sensitive to reductions in R0
    • some things to note with this calculator:
      • it is really designed to examine community spread and not cases brought in from outside the region
      • it would appear that given it displays calculated numbers of infected persons rather than tested confirmed cases, one should probably use the true fatality rate of around 0.7% rather than case fatality rates, and thus the hospitality rates should also be reduced to have the unconfirmed community cases added to the denominator and thus hospitalization rates should perhaps be reduced from 20% down to around 3-5%
      • unless you untick the display fatalities option, the chart of those in hospital is actually in ADDITION to fatalities to date so you need to look at the value on the left legend to determine how many are in hospital, not the Y axis value.
    • for a suburban region of population 750,000, incubation period 5 days, infectious period 6 days, CFR 0.7%, time to hospitalization 5 days, hospitalization rate 4%, hosp. LOS 15 days, time to death 18 days, initial R0 of 2.2:
      • if no social distancing measures and R0 remains at 2.2:
        • peak hospitalizations will occur at day 130 with around 6,400 in hospital although there are only around 1000 actual beds and deaths at this time would be around 2,100 with 70 deaths per day at CFR of 0.7% but given the health services would be overwhelmed, CFR may well be 5 times this much as is the Italian scenario. Hospitalized cases would continue for about 250 days as herd immunity exceeds 80% and total fatalities would reach over 4,000 if hospital capacity was able to meet demand but the realities are that fatalities would probably be 5 times this much.
      • if social distancing reduces R0 to 1.6:
        • peak hospitalizations will occur at day 180 with around 3,200 in hospital although there are only around 1000 actual beds and deaths at this time would be around 1,800 with 33 deaths per day at CFR of 0.7% but given the health services would be overwhelmed, CFR may well be 3-5 times this much as is the Italian scenario. Hospitalized cases would continue for about 1 year and presumably social distancing will need to be almost as long. Total fatalities would reach over 3,000 but may be 3-5x this much if system is over-whelmed.
      • if social distancing reduces R0 to 1.2:
        • peak hospitalizations will occur at day 270 with around 700 in hospital which is now manageable while deaths at this time would be around 840 with 7 deaths per day. Hospitalized cases would continue for almost 2 years and presumably social distancing will need to be almost as long. Total fatalities would reach over 1,600.
      • if extreme social distancing reduces R0 to 0.8:
        • peak hospitalizations will occur at day 25 after the reduction to R0 of 0.8 with around 45 in hospital and deaths at this time would be around 14, HOWEVER, borders would need to remain closed until a vaccine is available otherwise it will start all over again. Hospitalized cases would continue for about 1 year and presumably extreme social distancing will need to be almost as long. Total fatalities would be around 50.
  • scenario 2: July 2020 Stage 3 restrictions reduce R0 to 0.5
    • for Greater Melbourne population 4.5m, incubation period 5 days, infectious period 6 days, CFR 0.7%, time to hospitalization 7 days, hospitalization rate 6%, hosp. LOS 13 days, time to death 18 days, initial R0 of 1.8:
      • hospitalization peaks around 3 weeks after restrictions introduced at around 165 inpatients
      • after 2 months of restrictions:
        • inpatients fall to 50, deaths at around 70 and community infections at a potentially more controllable level of under 100-200
        • if restrictions then lifted and outbreaks not kept under control, risk of return to July levels very rapidly.
      • had stage 3 restrictions not been put in place and R0 was 1.8:
        • by 2 months: 50,000 infectious, peak hospitalisation of 33,000 inpatients well above capacity at 18wk mark and by 200 day mark, herd immunity obtained but with perhaps 350,000 deaths across Greater Melbourne as case fatality rate would become closer to that seen in northern Italy with an overwhelmed health system.
  • scenario 3: Aug 2020 Stage 4 restrictions only reduce R0 to 2.15
    • for Greater Melbourne population 4.5m, incubation period 5 days, infectious period 6 days, CFR 1.15%, time to hospitalization 7 days, hospitalization rate 4.7%, hosp. LOS 16 days, time to death 18 days, initial R0 of 2.5 (June 2020):
      • On 10th July (day 45 of 2nd wave), there were 1000 active cases
      • On 26th July there were over 4,000 active cases, 228 in hospital, 70 deaths this would fit with the model of R0 = 2.15 for the period 10th-26th July!
      • if this R0 were to continue at 2.15 for 10% of Melbourne's population who are less able to comply while 90% of the population comply strictly and do not get infected in this wave:
        • by 9th August, we would hit over 11,000 active cases, 40 hospital admissions a day with over 550 inpatients and deaths increasing to 11 per day for a total of over 130
        • by early Sept at day 100, we would hit over 45,000 active cases, 160 hospital admissions a day with over 3,000 inpatients and deaths increasing to 50 per day for a total of well over 800
        • by late Sept at day 126 hospital inpatients would peak at over 45,000 active cases, with over 6,000 inpatients and deaths increasing to 80 per day for a total of around 3,000 (probably a lot more as the hospital systems are now over-whelmed)
        • by Dec this wave would have almost ended as long as the 90% do not stop complying while there are infectious cases whilst 10% of Melbourne's population would have been infected with over 5,000 dying.
covid19_victoria.txt · Last modified: 2020/08/08 11:50 by gary1