A few days after his return to Seattle, his mother took him to his family doctor. He has tested it for various common infections including mumps, Lyme disease and, of course, sexually transmitted diseases. Everything came back normally.

Three weeks after returning from vacation, his mother and son – pale and 15 pounds thinner than in June – made their way through Chia Wang, Specialist infectious disease physician at Virginia Mason Hospital in downtown Seattle.

Wang listened to the strange litany of symptoms that affected the boy's summer. Most were gone now. He sometimes had sore throats, but no pressure. His appetite was better and his testicles were normal again. But he always felt so tired – not as if he had not slept, but as if every part of his body was worn out, as one feels after the sport. Of course, he added, he was still too tired to go to the gym.

Wang sent some blood tests to see if she could determine what he had, focusing on infections that he had not known. have been tested, including the Zika virus, which was first observed in the United States the previous summer, and ehrlichia, a tick-borne infection that can cause persistent fevers and is common on the east coast. . It was known that neither one nor the other caused orchitis.

"Is it dengue?" The mother asked Wang. Dengue is the fastest spread mosquito-borne disease in most parts of the world. It is rare in the United States because the mosquito species that transmit the virus, Aedes aegypti and Aedes albopictus, do not thrive here. But the mother had learned that there had been an outbreak in Hawaii the previous year.

Zika's carrying mosquito also carries dengue, so Wang thought it was logical to order both tests. Both viruses cause febrile illness, with body aches and usually a rash – although in Zika, the symptoms are often less severe. There are no drugs for these viral infections, just supportive care. Wang told the boy and his mother that the problem of the infection would probably not matter, as it seemed to heal. And even though it was not a virus but a bacterial infection, he had already taken weeks of extremely useful antibiotics.