[ExI] new new zealand cases

[Keith Henson]

<spike at rainier66.com> wrote:

> I am surprised at how hard it is to find the answer to an obvious question regarding the new New Zealand covid cases.  They went over 3 months with no new cases, yesterday they found 4 members of one family testing positive.  All the news I can find is about the new New Zealand lockdown, rather than the obvious question for an island with closed borders: how did the virus get there?

> Did it come in on the mail?

That would be my guess.  I think mail might be one case in a million,
but you get millions of mail deliveries, that's going to occasionally
cause cases to crop up.

Another example was a cluster of around 50 cases near Beijing that
look like the virus came in on refrigerated or frozen fish from
Europe.

I presume they will sequence the virus.  There is enough variation now
that the origin of those cases can probably be traced to a
geographical location.  Then you start asking the family where they
got mail from.

I can't find the reference, but I remember a case back in the 1950s
where an isolated base in the antarctic had a cold epidemic after a
mail drop.

> Are there still some travelers who are asymptomatic?  If it came in with no obvious mechanism, what could be the remaining unknown vector?  If there is an unknown vector (such as somehow being carried by birds or bats (?) then how can we be sure that lockdowns work?

Birds, no.  Bats, possible but very, very unlikely.  However, I would
consider the virus possibly circulating in cats and possibly dogs.
Again, this is unlikely, but this is one event in the whole NZ
population, so you have to consider the unlikely such as mail and
cats.

And lockdowns clearly work to reduce the spread of the virus.  But
having worked, the highly susceptible population makes NZ into a
sensitive culture test plate
.
I will follow this with great interest.

Keith