# How do Modern People pose a health threat to native people? **URL:** \ **Category:** Factual Questions\ **Created:** [February 1, 2019, 4:58pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794 "2019-02-01T16:58:06Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 1, 2019, 4:58pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/1 "2019-02-01T16:58:06Z")
I had childhood Chicken Pox and Measles. I’ve had the flu at least once. If I go deep into the jungle and shake a native’s hand. How could I transfer any diseases? I know the European explorers are blamed for passing on diseases. I’ve assumed someone in the expedition was actually sick and infected the native population. How can a disease I had 45 years ago hurt anyone? > **[American missionary accused of exposing an isolated tribe to potentially...](https://www.independent.co.uk/news/world/americas/brazil-steve-campbell-us-missionary-uncontacted-tribe-disease-hi-merima-a8743746.html)** > > ‘Probability of transmission of diseases is high,’ says Brazil’s ministry for indigenous affairs > [@](#): > > The Brazilian government has accused a missionary from the US of exposing an isolated indigenous tribe to potentially fatal diseases. > > \ > “It’s a case of rights violation and exposure to risk of death to isolated indigenous population,” said a spokesman for the Brazilian government’s Indigenous Affairs Department (Funai). > > Mr Campbell camped in the area the Hi-Merimã occupy and invaded one of the isolated tribe’s recently abandoned camping grounds, Funai said. ---
**Author:** ![leahcim](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@leahcim](https://boards.straightdope.com/u/leahcim)\ **Post date:** [February 1, 2019, 5:23pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/2 "2019-02-01T17:23:05Z")
Typhoid Mary famously spread typhoid without experiencing symptoms from it. And if you have had chicken pox, the virus is still in your system (although you are unlikely to spread it without symptoms) ---
**Author:** ![griffin1977](https://avatars.discourse-cdn.com/v4/letter/g/977dab/32.png) [@griffin1977](https://boards.straightdope.com/u/griffin1977)\ **Post date:** [February 1, 2019, 5:32pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/3 "2019-02-01T17:32:57Z")
There is a chance you are actually incubating a flu or cold right now (I am getting over one). I don’t know what percentage of the human race is about to carrying a cold or flu at any given time (particular in flu season), but its not an insignificant percentage. If your uninvited visitor is one of those people, then its game over. That said would a cold virus (rather than flu) be fatal to isolated populations? ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [February 1, 2019, 6:13pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/4 "2019-02-01T18:13:56Z")
> [@leahcim](#): > > And if you have had chicken pox, the virus is still in your system (although you are unlikely to spread it without symptoms) To amplify – chicken pox is a [retrovirus](https://en.wikipedia.org/wiki/Retrovirus). > [@](#): > > A retrovirus is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.[1] Such viruses are specifically classified as single-stranded positive-sense RNA viruses. > > Once inside the host cell’s cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backwards). The new DNA is then incorporated into the host cell genome by an integrase enzyme, at which point the retroviral DNA is referred to as a provirus. The host cell then treats the viral DNA as part of its own genome, transcribing and translating the viral genes along with the cell’s own genes, producing the proteins required to assemble new copies of the virus. It is difficult to detect the virus until it has infected the host. At that point, the infection will persist indefinitely. Once you’ve had it, it’s part of your cellular DNA forever. There are numerous viruses like this (herpes is a well-known example). ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [February 1, 2019, 6:24pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/5 "2019-02-01T18:24:51Z")
> [@griffin1977](#): > > That said would a cold virus (rather than flu) be fatal to isolated populations? According to an article I just read at lunch, yes. A Brazilian photographer named Sebastião Salgado went to the Amazon jungles to photograph the Korubu people. He says he was quarantined for a week before going to visit because “even a cold could kill them.” But then, he’s just a photographer not an epidemiologist. His info was probably second hand. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 1, 2019, 7:41pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/6 "2019-02-01T19:41:21Z")
I nearly forgot about the smallpox vaccination. I still have a faint scar. They quit routinely giving them in 1972. > **[Vaccine Basics | Smallpox | CDC](https://www.cdc.gov/smallpox/vaccine-basics/index.html)** > > Vaccine Basics ---
**Author:** ![leahcim](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@leahcim](https://boards.straightdope.com/u/leahcim)\ **Post date:** [February 1, 2019, 11:05pm UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/7 "2019-02-01T23:05:42Z")
More generally, our really nasty diseases come from animals – they are mild diseases in animals that become dangerous in humans. Cultures where there is a history of prolonged contact with animals through farming have had more exposure to those diseases in the past so will be generally more immune than cultures where there is no (animal) farming. ---
**Author:** ![DinoR](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dinor/32/2821_2.png) [@DinoR](https://boards.straightdope.com/u/DinoR)\ **Post date:** [February 2, 2019, 1:21am UTC](https://boards.straightdope.com/t/how-do-modern-people-pose-a-health-threat-to-native-people/828794/8 "2019-02-02T01:21:57Z")
> [@aceplace57](#): > > I nearly forgot about the smallpox vaccination. I still have a faint scar. That’s a case where an isolated population in Brazil might have more protection than most in the developed world at this time. The vaccine isn’t actually an exposure to dead or weakened smallpox. It’s started with an exposure to cowpox which is less dangerous and happens to confer immunity to smallpox. It morphed into an exposure to a virus related to both of them but still not actually smallpox. When I got a smallpox booster in 2007 (Thanks Army!) there was an NCO waiting with me that was getting a second attempt at the vaccine. He hadn’t formed the pustule that is associated with forming the immunity. His civilian job was on a cattle farm. He’d gotten the extra dosing on the first attempt because of his occupation and then came back for another attempt.\* If that isolated tribe has cattle and those cattle hadn’t always been isolated they might already be carrying cowpox. There’s also some related viruses that might be flitting around other types of their livestock that could also have an impact on immunity. (The opposite direction, using smallpox vaccine to control an outbreak of the related monkeypox virus happened in the US in 2003.) A lower tech society with more interaction with their livestock could thus be better protected from smallpox. They may be regularly exposed to something that confers immunity without killing them. - - The vaccine is not an injection. It’s delivered with a two bladed needle. It looks a bit like a small seafood fork. They dip it in the vaccine and then poke it into your arm.“Extra dosing” is just increasing how many times they poke the infected fork into your arm. I was born a little before the end of routine vaccination so I was presumed vaccinated and got the extra pokey version. That poor NCO got the super pokey variant. He was not amused.