Answer:
The author uses this passage to help the reader focus on why Dr. Dowell is in Thailand.
Step-by-step explanation:
In the supporting text "Disease Central" in John DiConsiglio's When Birds Get Flu, the author included details on the reason why Dr. Dowell had to go to Thailand. The scientists’ first trip overseas to Southeast Asia is to work on the "epidemic of smallpox and cholera" that has taken over the people.
This passage is included so that the readers will understand why Dr. Dowell had to be there in Thailand. It also allows the writer to provide a background on why the scientists and other experts had to make an overseas trip. It also tells us why a US-based doctor from the CDC had to come to another side of the world.