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Comment by sago | Hacker News Reader

Every day hundreds of thousands of people fly in and out of Brazil to and from all corners of the world. Rio Galeão alone handles 17m passengers per year, much more than the total number of Olympic tickets available (most of which are sold to Brazilians, and most of the attendees buy more than just one).

Nobody I can find is giving credible numbers that show the olympics will constitute a significant increase to affected areas over the year as a whole (edit: as adevine points out, below, the article puts the increase at c 0.0025), nor that travel is currently only from a handful of places worldwide.

If international travel to Rio is a public health problem, then focussing on the olympics is pure tokenism.

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What percent of current travel comes from areas where Zika could exist, but doesn't? And what amount of travel from such places will the Olympics bring?

Total volume isn't the right consideration if almost all visitors are from places that Zika already exists or can't exist.

Update: I checked the stats: 93% of visitors to Brazil come from places where Zika already is or can't go:

https://en.m.wikipedia.org/wiki/Tourism_in_Brazil

5% are from Asia. Africa isn't mentioned, but it must be less than 2%, part of which would be from North African countries that can't get Zika.

The olympics will bring visitors from every country. It should increase the speed with which the virus reaches sub Saharan African, and Southern Asia.

I don't think your information actually allays any of the concerns, as the total stats refer to visitors from different countries than those who will be visiting during the olympics.

You also have to see probability of someone getting infacted. I am seeing number in range of 500 for population of 10M. I suspected car accidents probably has higher fatality rates.

> I am seeing number in range of 500 for population of 10M.

Over what time period?

I spent a few minutes on it and it looks like, if Zika did not exist, the Olympics would add 10% of extra total yearly tourism to Rio. Some complications:

* tourism to Rio this year is presumably lower than the baseline I'm using because it is presently the site of a Zika outbreak.

* the tourism into Rio for the Olympics is especially international, so it may be reasonable to be especially concerned about its effect on global transmission of the virus.

I think the people advocating for canceling the Olympics understand that it's only 10% extra tourism, but still think that small percentage of extra tourism is a bad outcome.

I posted the article. I think the second point is most worrisome. Most visitors to Rio are either:

1. From Latin America, where Zika already is, or 2. From US/Europe, where Zika can't go.

The olmypics will bring a delegation from every country + tourists from more of those countries. So Zika can spread to other regions. And once it spreads anywhere in a large region it will likely spread everywhere.

> From US/Europe, where Zika can't go.

What? There have been Zika cases in the US.

What he meant was that while Zika can be carried anywhere by humans, it won't spread in areas which don't have the right type of mosquitos.

Except that it is communicable between humans (and, presumably, other hosts).

It can be communicated between humans, but it sounds like the rate at which that occurs is far too low to cause an epidemic.

That's what I meant. It's already going to spread through the US regardless because it's physically connected to areas where Zika exists.

I suppose Southern Europe might be able to get it? I'm not sure if the extent of the mosquitos there.

Update: only a very small bit of southern Spain. So not really a concern for Europe or North Africa. Also, they don't have the sort of contiguous area where it would spread across a whole continent.

Map of Aedes Aegyptus: http://m.imgur.com/uCegZHS?r

On the east coast, the mosquitos that carry Zika are found as far north as New York.

This appears to be true: http://www.cdc.gov/zika/vector/range.html

The range shown here includes all of the Southeast and Texas, much of the southern Midwest, and California up to and including the Bay Area.

This is only the range of Aedes aegypti. Whether a particular strain of the mosquito can carry Zika remains to be seen (though quite likely) as Aedes aegypti is very heterogenous.

That point is argued in the article:

> "There’s been some claims that if the Olympics happen, it’s going to disseminate the virus everywhere, it’s going to amplify it," Frieden said. "Well, we looked at the numbers. The Olympics account for less than one quarter of 1 percent of all travel to Zika-affected areas."

I think this was a plot to a Michael Crichton novel, except instead of Zina it was a terrorist group's bioweapon.

Tom Clancy's Rainbow Six had a created virus released at the Olympics as a plot point.

If Olympics increase annual tourism by 10% as I have seen elsewhere and in this thread, then that effectively doubles the tourism to Rio for the duration of the Olympics.

As others have pointed out, there are poor countries that have trouble eradicating mosquito borne disease (think malaria, which is transmitted via the same species as zika) that do not currently have zika. Increasing the speed of the spread of the disease does not seem logical given that we do not even have a vaccine.

Moreover, this is a rapidly evolving disease which is also sexually transmitted.

I would not recommend traveling to Rio or other Zika-invested countries right now. You can't just get vaccinated before travelling.

Doubling the tourism to Brazil for a month seems like a bad idea at best, hazardous at worst.

http://www.vox.com/science-and-health/2016/2/1/10887868/worl...

There are a couple of factors that could make Olympic travelers much more likely than the general non-Olympic traveler to contract or spread the virus.

1. The Olympics venues are in places that have been particularly hard hit by the virus.

2. Much of those non-Olympic travelers are business travelers on short visits. Olympic visitors will typically visit for longer. Risk of infection should go up as length of stay goes up.

3. The virus can be sexually transmitted between humans. I'd expect that Olympic visitors have a higher probability than the average visitor of engaging in sex during their stay.

It's not the full set of hundreds of thousands of people that fly in and out of Brazil each day that you should be comparing against, but rather the subset of those that are there for vacations lasting at least a week or two.

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