COVID-19: Can NZ do contact-tracing effectively quickly enough?

A little list

A contact list
What is the gist
Who did you see
Near recently
Take care none missed

Alan Grace
24 April 2020

Remember to keep a list of all your contacts to assist with contact-tracing in case you or someone you have been in contact with get infected.

Contract-tracing should ideally be achieved within three days.

Can NZ achieve this target?

Try the challenges at the bottom of this post.

The Government is looking at apps to assist with contact-tracing.
We may look at possible scenarios for an app in another post.

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Update:

Please see:
https://yournz.org/2020/04/27/contact-tracing-apps-versus-privacy/
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We look at randomly-generated (binary) trees to get an idea of what the real-life situation may look like.

Below is a random tree generated in Excel with p=0.5 for branching.

Note: Each tree starts at the top left of the tree.

We started with a different approach to generate trees using p=0.7:

Challenge 1

Suppose you are employed to carry out contact-tracing.

Assume the above trees show cases that are already known.

You have been told a contact has a name beginning with a vowel (A,E,I,O,U).

Identify from the above trees all possible contacts.

How many potential contacts are there?

How many trees are there in each of the above images?

Email me your highlighted possible contacts.

Challenge 2

Use Excel to randomly generate trees like the above.

Prize: A (virtual) chocolate fish for the first person to successfully complete this challenge. Email me your Excel spreadsheet.

Here are pdf versions of the trees:
tree19
tree8

Challenge 3

Suppose the cells without text (blank cells) are a maze.

How many ways can you find to go from the left side to the right side?

What may be a possible significance of this?

 

My little List

As some days may happen
That a contact must be found
I’ve got a little list
I’ve got a little list
Of my recent contacts
Who might well be underground
And never should be missed
They never should be missed

Alan Grace
24 April 2020
(with apologies to Gilbert and Sullivan and Eric Idle)

Little List song

From the 1987 Jonathan Miller production of “The Mikado” starring Eric Idle

Historical notes: The original “Little List Song” from “The Mikado” by Gilbert and Sullivan has long been acknowledged as fairly dated. So when Eric Idle starred in a production by the English National Opera,, he rewrote the lyrics of the song to include topical references. Hence the song could (and did) change from night to night. This is just one version of the updated song:

As some days may happen
That a victim must be found
I’ve got a little list
I’ve got a little list
Of society offenders
Who might well be underground
And never would be missed
They never would be missed

 

There’s weightlifters and bodybuilders
People of that sort
Bank robbers who retire to spend
The minute they get caught
Bishops who don’t believe in God
Chief constables who do
All people who host chat shows
And the guests who’s on them too
And customs men who fumbling through your underwear insist
I don’t think they’d be missed
I’m sure they’d not be missed

 

Chorus: He’s got them on the list
He’s got them on the list
And then none of them be missed
And none of them be missed

 

There’s the people with pretentious names
Like Justin, Trish, and Rob
And the gynaecologist
I’ve got him on the list
All muggers, joggers, buggers, floggers
People who play golf
They never would be missed
They never would be missed

 

All waitresses who make you wait
Accountants of all kinds
And actresses who kiss and tell
And wiggle their behinds
And pouncy little singers who to entertain us try
By dressing up like women and by singing far too high
And who on close observance must be either stoned or pissed
I don’t think they’d be missed
I’m sure they not be missed

 

Chorus: He’s got them on the list
He’s got them on the list
And then none of them be missed
And none of them be missed

 

There’s the beggars who write letters
From the inland revenue
And the gossip columnist
I’ve got him on the list
All critics and comedians and opera singers too
And none of them be missed
And none of them be missed

 

All traffic wardens, bankers,
Men who sell Venetian blinds
All advertising chappies
And Australians of all kinds
And nasty little editors whose papers are the pits
Who fill their rags with gossip
And huge and floppy… ritz.
And girls who sell the stories
Of the Tories they have kissed
But you must have got the gist
‘Cause none of them be missed

 

Chorus: You may put them on the list
You may put them on the list
And then none of them be missed
And none of them be missed

 

Original song by: Gilbert and Sullivan

New lyrics by: Eric Idle

My other COVID-19 posts can be found here:
https://aaamazingphoenix.wordpress.com/tag/coronavirus/

Data for my posts can be found at:
https://www.worldometers.info/coronavirus/
https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_New_Zealand

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