[sonicxxg]

This recent coronavirus outbreak has been very enlightening, cause it gaves us more information on why cruises are a bad idea, and perfect for an epidemic. The same air is recirculating among all cabins.

However, it does not explain why we haven't heard of flu outbreaks in cruises before this coronavirus. It seems cruises are perfect for the proliferation of any airborne virus.

[dragonwriter]

> This recent coronavirus outbreak has been very enlightening, cause it gaves us more information on why cruises are a bad idea, and perfect for an epidemic. The same air is recirculating among all cabins.

We already knew that about cruises.

> However, it does not explain why we haven't heard of flu outbreaks in cruises before this coronavirus

We have, actually, but we don't hear about it much, because, except with the scrutiny occurring during this COVID-19 outbreak, which led to media exposure for a cruise ship flu outbreak [0], cruise ships are only required track and report when gastrointestinal disease hits a certain threshold, not respiratory ailments. [1]

[0] https://www.baltimoresun.com/health/bs-hs-royal-carribean-fl...

[1] https://www.cdc.gov/nceh/vsp/surv/gilist.htm

[ridaj]

Interesting. On [0], it seems like people on that ship were not tested for coronavirus though, because they weren't meeting criteria that the CDC had laid out for who could be tested. Let's hope it was really just the flu!...

[TheCapn]

>However, it does not explain why we haven't heard of flu outbreaks in cruises before this coronavirus.

Anecdotally I hear about it almost every time the topic of cruises come up on Reddit or other social media. I just don't think its particularly newsworthy so it isn't making headlines. Cruise ships and Conventions are pretty similar in the sense that people just get notoriously sick after attending is my understanding.

[phonypc]

Why would recirculated air be a concern on cruise ships? They're not airplanes. Also COVID-19 only seems to be airborne in the sense that you can get it from coughed/sneezed droplets directly from a sick person, not aerosols that can be widely distributed.

[new2628]

So how did 696 passengers on Diamond Princess become infected?

[barry-cotter]

https://en.wikipedia.org/wiki/2020_coronavirus_outbreak_on_c...

> Kentaro Iwata, an infectious diseases expert at Kobe University who visited the ship, strongly criticised the management of the situation in two widely circulated YouTube videos published on 18 February.[36][37][38][39] He called Diamond Princess a "COVID-19 mill".[40] He said that the areas possibly contaminated by the virus were not in any way separated from virus-free areas, there were numerous lapses in infection control measures, and that there was no professional in charge of infection prevention—the bureaucrats were in charge of everything.

[mtmail]

"Ocean-going ships are actually legally required to have both body bags and a morgue (they mostly have space for three or four bodies, but it depends on the size of the ship)." https://www.telegraph.co.uk/travel/cruises/galleries/secrets...

[lowercased]

I've been on a whole 2 in my life, but enjoyed both trips quite a lot - especially when people get off at various ports and I have huge areas mostly to myself :). Understanding there's some potential for this sort of thing, but may take the risk again in the future.

[new2628]

For the locals in those ports though ...

[formercoder]

Agree, I’ve been on 20+ cruises. Will continue doing so after this has passed.

[dboreham]

I'm interested in what the known spreading instances on ships and at conferences tell us about how the virus is transmitted.

As I understand it, the message from CDC etc is, roughly: It's transmitted through droplets coughed or sneezed from one person that then end up through common touching of not-cleaned surfaces and thence into the body through face-touching.

My gut feel is that if that's how transmission occurs, we shouldn't see infection spread between large numbers of people who were simply present in the same room as each other for a few days.

Which makes me wonder if all the hand washing is just "Epidemiology Theater".

[barry-cotter]

> My gut feel is that if that's how transmission occurs, we shouldn't see infection spread between large numbers of people who were simply present in the same room as each other for a few days.

People cough and sneeze all the time, even healthy people, and the droplets of saliva from that land on surfaces that other people touch and then they touch their faces, rub their eyes and pick their noses. So the virus will spread in the air and also by transmission onto mucus membranes from your hands. It’s not airborne but there is droplet transmission. The danger is relatively small if people don’t touch, like shaking hands, hugging or kissing, and if surfaces are wiped down with disinfectants regularly and everyone washes their hands but that does not describe most people’s experience of being in a room with other people for a few days.

[dboreham]

I read in another thread that sneezing aerosolizes the payload such that it will stay in suspension in a large volume of air (a large room for example) for hours. I'd call that "airborne transmission" but it seems that means something different. That being the case, could it be that the hand washing is more to do with reducing the surface area onto which a droplet can land and make it into the target's body? This would explain quite well how someone can infect 50 other people in a large room, and also why hand washing is helpful (but not a 100% protection since droplets can still float in through the nose and mouth).

[ridaj]

There are plenty of commonly-touched surfaces when people spend a long time in the same space: door handles, elevator buttons, countertops, buffet utensils, gym equipment, money...

I don't think the hand-washing is epidemiology theater, in part based on this thread: https://twitter.com/PalliThordarson/status/12365493051895971...

[godshatter]

Not sure about conferences, but for cruise ships buffets would be my guess. Most people on cruise ships eat at least a few meals at an overcrowded buffet. Multiple people touching serving utensils, stacks of plates, fishing for silverware, etc. Not to mention sneezing around open food containers.

[dboreham]

I got the impression people were still being infected on the Diamond Princess after they were confined to their cabins.

[dboreham]

Perhaps because most people already have some immunity to flu and other not-new viruses? Those viruses are spread around a ship just as much but the effect is less noticeable.

[rtkwe]

Coronavirus has a lot going for it over the flu; a very long incubation period where you can still actually spread the virus before you start really showing symptoms, higher virulence, and a lack of vaccines.