Wikipedia:Reference desk/Archives/Miscellaneous/2021 December 3

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December 3

Kappa variant and Delta variant of COVID-19 in Australia

I was wondering when did the Delta variant (B.1.167.2) overtake the Kappa variant (B.1.167.1) in terms of most common infection in Australia? (Fran Bosh (talk) 20:08, 3 December 2021 (UTC))

Near as I can tell, the Kappa variant has never been the most common of the SARS-CoV-2 virus in Australia. According to This article from 24 June, 2021, the Delta variant had only recently surpassed the Alpha variant in Australia as the most commonly transmitted variant. Kappa is mentioned there, but as a less prominent variant than the other two in Australia. --Jayron32 20:14, 3 December 2021 (UTC)

OK thanks. I was under the impression that Kappa was the most common variant in May or June & then later in the year the Delta variant overtook it but maybe I was wrong. (Fran Bosh (talk) 20:16, 4 December 2021 (UTC))

My impression by reading that article was that Kappa was a concerning variant in the sense that it was relatively new, but that it never overtook either Alpha or Delta. --Jayron32 13:06, 6 December 2021 (UTC)

(EC) It may be technically true in a very limited way. For most of this year, Australia had very limited community transmission until about the middle of the year. In May, there was a small outbreak in Victoria or I believe Melbourne in particular which involved the Kappa variant so I suspect it was the dominant variant for community cases during this time. However it was a small outbreak, I think ending up maybe around 60 cases see e.g. [1]. Not long after that there were outbreaks of Delta in both Victoria and NSW which quickly spread wide enough that they've ended Australia being free of SARS-CoV-2 community transmissions.

The link Jayron32 shared appears to relate to detections in MIQ or whatever you call it in Australia i.e. cases which have come in from overseas (whether directly brought in or sometimes transmissions among them). They're not irrelevant since they're ultimately where community transmissions come from, but they're generally treated distinctly from community transmissions. (Although there is always a grey area e.g. if there's a detection in a border worker which doesn't spread to anyone else.)

But and this gets to one of the key distinctions from most other countries, the almost non existent community transmission meant that for long stretches such cases were the majority of cases in Australia. Therefore if you just looked at case numbers, alpha may have seemed to be the dominant variant. Although I don't think it's particularly meaningful to say kappa was the dominant variant in Australia when you're just talking about a single small outbreak either.

P.S. theoretically COVID-19 clusters in Australia might be useful here, it doesn't list the variant but it should give an idea of the level of community transmission. Unfortunately sorting by date seems to be broken for reasons I can't work out.

Nil Einne (talk) 13:32, 6 December 2021 (UTC)

I should add that while I don't know that much about the older Australian quarantine system, it seems reasonably possible that although that Kappa outbreak was relatively small during it even taking all detections in border quarantine into account there were still more cases from the community outbreak. Therefore even on the basis of all new cases regardless where they were, there may have been maybe 3 weeks or something where Kappa was technically dominant. Even more likely if you restrict yourself to Victoria. Nil Einne (talk) 15:21, 6 December 2021 (UTC)