# Why do influenza strains seem to originate in China **URL:** \ **Category:** Factual Questions\ **Created:** [February 26, 2020, 1:21pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549 "2020-02-26T13:21:41Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Cardigan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cardigan/32/187_2.png) [@Cardigan](https://boards.straightdope.com/u/Cardigan)\ **Post date:** [February 26, 2020, 1:21pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/1 "2020-02-26T13:21:41Z")
Why does it seem that influenza strains always seem to originate in China? ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [February 26, 2020, 1:29pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/2 "2020-02-26T13:29:04Z")
Do they really? A lot of H1N1 strains appear to have been originated in the US or Europe. A lot (but not all) of H3N2 strains do seem to flow out of China, but China also has the largest population of any country on the planet. It’s not true at a simple glance. There’s plenty of counterexamples in the past decade. Maybe confirmation bias? ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [February 26, 2020, 1:41pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/3 "2020-02-26T13:41:59Z")
It’s [those damn bats.](https://en.wikipedia.org/wiki/Horseshoe_bat#As_disease_reservoirs) ---
**Author:** ![GreenWyvern](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/greenwyvern/32/2834_2.png) [@GreenWyvern](https://boards.straightdope.com/u/GreenWyvern)\ **Post date:** [February 26, 2020, 2:10pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/4 "2020-02-26T14:10:06Z")
A cut above the usual conspiracy theories… [Covid-19 may be man-made, claims Taiwan scholar](https://asiatimes.com/2020/02/covid-19-may-be-man-made-claims-taiwan-scholar/) \*A professor at the National Taiwan University claims the highly infectious virus could be ‘synthetic’ \* > [@](#): > > “Researchers likely synthesized the Covid-19, although more studies are needed to be certain,” NTU professor Fang Chi-tai told a forum on disease control and prevention in Taipei held by the Taiwan Public Health Association earlier this month. > > During his presentation, Fang outlined several hypotheses raised by Taiwanese and overseas researchers, including the probability that the virus was “man-made” and was leaked from the Wuhan Institute of Virology due to gross mismanagement. Fang said the Wuhan facility’s biosafety level-4 laboratory was used to store, handle and research samples of SARS, Ebola and other deadly infectious viruses. “Given China’s poor track record of lab safety management, including a leakage of the SARS virus at a state lab in 2004, it is possible that a virus escaped from the Wuhan facility and resulted in the epidemic,” Fang was quoted by Taiwan’s Central News Agency and the Taipei Times as saying. > > He added that analyses of the Covid-19 virus have shown that it had a 96% genetic similarity with an RaTG13 bat virus also stored at the institute, and that the Covid-19 could be “manufactured” by modifying the RaTG13 virus. > > Fang also revealed that French researchers had discovered four more amino acids in the gene sequence of Covid-19 than other known coronaviruses, which could be added artificially to make the viral transmission easier. Fang’s theory is that natural mutations of viruses will only result in small, singular changes, and it is suspicious to see a naturally mutated virus suddenly take on four amino acids. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [February 26, 2020, 2:18pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/5 "2020-02-26T14:18:34Z")
There’s at least one other thread on the Dope where the idea that Covid-19 is man made or in anyway connected to the biolab in Wuhan is shown to be extremely unlikely. I don’t know enough biology to directly refute his claim, but from what I’ve read elsewhere it seems like CT material. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 26, 2020, 3:03pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/6 "2020-02-26T15:03:29Z")
> [@GreenWyvern](#): > > A cut above the usual conspiracy theories… > > [Covid-19 may be man-made, claims Taiwan scholar](https://asiatimes.com/2020/02/covid-19-may-be-man-made-claims-taiwan-scholar/) > \*A professor at the National Taiwan University claims the highly infectious virus could be ‘synthetic’ \* > [@Telemark](#): > > There’s at least one other thread on the Dope where the idea that Covid-19 is man made or in anyway connected to the biolab in Wuhan is shown to be extremely unlikely. I don’t know enough biology to directly refute his claim, but from what I’ve read elsewhere it seems like CT material. **Moderator Note** Since there is another thread on this, I don’t think we need additional discussion of a synthetic origin here. Let’s not hijack the thread in that direction. Colibri General Questions Moderator ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [February 26, 2020, 3:35pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/7 "2020-02-26T15:35:57Z")
Observational bias. There’s pretty compelling evidence that the 1918 "Spanish Influenza"[originated in Kansas.](https://virus.stanford.edu/uda/) The 2009 Swine Flu pandemic came [from Mexico.](https://en.wikipedia.org/wiki/Swine_influenza) A 1963 outbreak of H3N8[started in Miami](https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H3N8). ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 26, 2020, 5:16pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/8 "2020-02-26T17:16:52Z")
One theory I read - Pigs have a very similar biology to humans, so we are more susceptible to pig diseases than many others. China and southeast Asia generally, pigs seem to be a major livestock; and they are kept on small farms in smaller pens which are very messy. They are also on migratory bird routes, and there are a lot of wildlife in the area. So the pigs are rolling around in mud that has a lot of bacteria and viruses from outside sources in it. The level of hygiene and lack of modern cleaning and running water facilities, live markets, etc. aggravate the risk. Many rural and semirural butcher facilities are fairly small and less regulated. It’s not unusual for bacteria and viruses to “trade” DNA during reproduction, so this is a fairly risky setup. (Contrast this with US “factory farms” where humans rarely interact with pigs and wear moonsuits when venturing into the giant isolated pig barns; and animals have very little human contact until slaughtered in factories which are monitored for hygenic procedures). Also, with small farms, one pig or chicken represents a much bigger proportion of a farmer’s wealth, and there is a bigger incentive to hide or quickly slaughter a sick animal and pretend it is OK, than allow it to be disposed of as diseased. So you have a huge area where humans interact closely with animals who are living in a giant petri dish for creating interesting new variants on assorted diseases. Mix and match billions (trillions) of disease agents and once in a while one will emerge with interesting consequences. ---
**Author:** ![russian\_heel](https://avatars.discourse-cdn.com/v4/letter/r/f05b48/32.png) [@russian\_heel](https://boards.straightdope.com/u/russian_heel)\ **Post date:** [March 1, 2020, 5:37am UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/9 "2020-03-01T05:37:17Z")
> [@Machine\_Elf](#): > > It’s [those damn bats.](https://en.wikipedia.org/wiki/Horseshoe_bat#As_disease_reservoirs) Not only does China have a bad history of treatment of animals with strange dietary choices that may have lead to the COVID-19 transmission from animal to human, but its major cities are overcrowded, often unhygienic, with a low level healthcare system, and polluted, making China a perfect petri dish for many diseases. Not every disease comes from China, but if I were a Virus, its the first country I’d pick to feed on especially with the international vectors it offers. ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [March 1, 2020, 6:04am UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/10 "2020-03-01T06:04:34Z")
> [@russian\_heel](#): > > Not only does China have a bad history of treatment of animals with strange dietary choices that may have lead to the COVID-19 transmission from animal to human, but its major cities are overcrowded, often unhygienic, with a low level healthcare system, and polluted, making China a perfect petri dish for many diseases. Not every disease comes from China, but if I were a Virus, its the first country I’d pick to feed on especially with the international vectors it offers. Those criteria don’t actually leave out a lot of places. Human-animal interactions take place in all sorts of settings. No need to travel all the way from wherever you are in virus form to the skeezier bits of Wuhan. Just pick anywhere people live near some sort of animal, and are complacent, thinking that viruses only come from China. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [March 1, 2020, 8:07am UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/11 "2020-03-01T08:07:55Z")
I’ve heard it is a combination of population density, _animal_ population density, subsistence farming, and the way that meat tends to be prepped & cooked. There are lots more opportunities for animal-to-human transmission. On top of that, tourism is about 23% of China’s GDP. For comparison, it’s about 3% of the US’s. So viral outbreaks in China are international news, and also more likely to leave China. Personally, I think statistics plays a role as well. Because very close to 1/5 of the world’s population lives in China, it would make sense that 1/5 of new human viruses arise in China. That sounds about right, albeit, the deadliest viruses don’t seem to come from China. HIV, the hemorrhagic fevers, Swine flu, Spanish flu & H1N1 did not come from China. SARS was not especially deadly. ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [March 1, 2020, 9:12am UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/12 "2020-03-01T09:12:12Z")
It’s difficult to project death percentages relative to influenza for the coronavirus given so much uncertainty in reported cases. ---
**Author:** ![Aspidistra](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aspidistra/32/3894_2.png) [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)\ **Post date:** [March 1, 2020, 9:22am UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/13 "2020-03-01T09:22:17Z")
I have no idea what countries different influenza strains come from. Is there actual information on this somewhere? ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [March 1, 2020, 12:16pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/14 "2020-03-01T12:16:05Z")
> [@Aspidistra](#): > > I have no idea what countries different influenza strains come from. Is there actual information on this somewhere? Not quite an answer but [an interesting article](https://www.researchgate.net/publication/335070476_Animal_Influenza_Virus_Infections_in_Humans_A_Commentary) on different possible animal hosts for influenzas. Written a few months ago, and with a focus on commercial farming species and domesticates, they put [and probably lost] their money on pigs. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [March 1, 2020, 2:24pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/15 "2020-03-01T14:24:52Z")
North Carolina exports pigs to China. As does Virginia. I don’t think we sell bats, though. ---
**Author:** ![RioRico](https://avatars.discourse-cdn.com/v4/letter/r/f04885/32.png) [@RioRico](https://boards.straightdope.com/u/RioRico)\ **Post date:** [March 1, 2020, 9:39pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/16 "2020-03-01T21:39:31Z")
> [@Triskadecamus](#): > > North Carolina exports pigs to China. As does Virginia. I don’t think we sell bats, though. No, Louisville Sluggers still come from Kentucky. 🆒 ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [March 2, 2020, 9:00pm UTC](https://boards.straightdope.com/t/why-do-influenza-strains-seem-to-originate-in-china/848549/17 "2020-03-02T21:00:04Z")
> [@RivkahChaya](#): > > On top of that, tourism is about 23% of China’s GDP. For comparison, it’s about 3% of the US’s. So viral outbreaks in China are international news, and also more likely to leave China. I think your GDP numbers are wrong there (my cite says 11% of GDP for China). But they’re _also_ misleading. According to [this cite](https://ceoworld.biz/2016/04/26/worlds-top-10-visited-countries-international-tourists-2015/), China has the 4th-most international tourists, the US has the second-most. All you’re measuring with GDP numbers is that the US has _lots of other industries_ that contribute a lot of money to GDP. Number of international tourists is almost certainly a better measure of how well diseases will leave a country than number dollars spent, and it’s certainly a better measure than percentage of dollars spent.