BRING BACK DDT: Agonizing Tropical Disease Comes To The United States — To Stay? “To this point, all the US residents diagnosed with chikungunya were infected outside the country; there is no evidence that anyone has acquired the disease within the US. Health authorities wonder, though, whether that can happen. Once the virus multiples in someone’s blood enough to cause symptoms, it can be picked up by a mosquito that bites that person, and then transmitted when the bug bites someone else in turn. That pattern has caused the mosquito-borne disease dengue to become re-established in Florida. The same mosquito species that spread dengue spread chikungunya as well.”