Most native peoples didn’t have large population centres filled with domesticated animals and human shit in water supplies.
Also, not directly related to the question, but I’m not aware of any cases of indigenous peoples *intentionally* spreading disease to European colonisers. But, when the British arrived to colonise Australia, they brought with them several vials of small pox pathogens. While we do not technically know that these vials were used to spread small pox to the indigenous Australians, we do know that the vials went missing and European diseases killed up to 90% of the indigenous population….
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