Variant or better case tracking?

Lockdown of Victoria Will be extended It will take another week to handle the growing number of community cases, which currently reaches 60.

However, questions remain about what is behind these incidents.Victorian COVID-19 Inspection Commander Jeroen Weimar Said yesterday In about 4-5 cases, the virus was transmitted only by “temporary contact”.

today, We heard from About Brett Sutton, Chief Health Officer of Victoria 1 case suspected Infected when visiting the site for about 2 hours rear There was an infected person. The source case has been around for a long time and was described as a poorly ventilated space.

Nonetheless, this is in line with the spread of aerosols that we have become more and more concerned about, and this is probably the first record of quarantine outside this hotel.

Health officials also heard today that about 10% of cases were associated with more accidental exposures, including “Tier 2” sites (Victoria has released exposure sites at risk. Explain and Tier 1 sites are the most risky).

So was it the virus that led to the discovery of such accidental exposure, or was it a more focused effort to track the case?

Is it a virus?

Despite today’s news, people are less likely to get infected by passing someone on the street.

In most cases, people were infected by very close contact or in certain conditions.Primary subcontractor“As a known case, the exposure site there at the same time.

There is evidence that Indian-related variants are more infectious. However, the strain of this particular Indian subspecies B.1.617.1 may not be: Infectious As another pedigree.

This emphasizes how important it is to contain the increased risk of spread as soon as possible to the extent that it is still manageable.

On average, in the subspecies of concern that are currently prevalent in Victoria, one case can infect 15% of household contacts instead of the 10% seen in 2020. The jump of the case number becomes large.

The way the virus spreads within the cluster has not changed. In some cases, the virus is not transmitted, and in a small number, it is transmitted to many people.

If this virus strain is much more contagious than the original strain, it is expected that many cases will be seen. This strain has been in our community for a month, but has not been detected and has been running for free for over 2 weeks. If this is true, there will be more than 60 cases.

Also good at tracking cases

The main change since the second wave in Victoria last year is that we are doing forensic analysis of all cases and are good at finding accidental connections between cases.

We are currently publishing a list of venues with exposure times, with more people participating in the test than during the peak of the second wave in Victoria. We also have check-in data for many venues.

This provides more reliable measurements of both total spread and pathways of viral infection than outbreaks in the second wave or in communities of this size.

Transmissions associated with more casual exposure would have been much more likely to be overlooked before. Even if these cases were picked up, they could have been counted as “mysterious cases”, accounting for 18% of all cases in 2020. A clear link between these cases and known cases. It was not known where these cases were infected because of the lack of.

This time I’m doing much better with only three outbound events that aren’t fully understood yet.

What about this “temporary contact”?

The four or five cases Weimar mentioned yesterday relate to various indoor exposure sites such as exhibition halls, Telstra stores, local grocery stores, and shopping strips.

This is where people may have come into direct contact with the case, but if the definitive exposure event is not documented, check-in will not occur and people will not know each other.

Therefore, as we know so far, there was a crossover between the time most cases were present and the time the contact was infected. And 90% of these are in environments known to be at high risk of infection, especially in homes and workplaces where long hours of contact are repeated indoors.

Yesterday, more casual contact at exhibition halls and Telstra stores could have overlapped with cases in a small closed area, long enough to receive an infectious dose.

Another example Sutton provided today was an infection that began with someone sitting in the same outdoor area as the hotel bistro case. We know that the risk is generally low in an outdoor environment, but on autumn days it turns out that this is sufficient.

Due to the current confirmed infection in the beer garden, all nearby individuals are reclassified as primary close contacts and require 14 days of quarantine, even with negative results. I’m sorry, but it’s better to be safe.

Therefore, it is very important to check in with a QR code. You don’t always know the name of the person standing (or sitting) next to you. This is also why more retail stores and public facilities require check-in throughout the state. Being able to identify contacts with these settings removes some of the horror associated with this more casual spread.

So what should we do about this?

This latest news emphasizes the importance of QR codes and check-in. While shopping, I don’t know who is standing next to me in a long line. Further expansion of QR codes, which are now known to be at risk, such as retail stores, grocery stores, and exhibition halls, is a good move.

The message does not change. If you have symptoms or are instructed by public health authorities, you will be examined and quarantined if necessary. Pay particular attention to those exposed sites, especially if you just stopped by for a cup of coffee.

But you don’t have to worry too much about COVID-19 being spread by “temporary contact”. The precautions we know (hygiene, distance, masks) are still in effect and are our best protection.

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