was biomathematics, the use of mathematical models to help
understand phenomena in biology. He was in charge of the predictive
modeling efforts at Theranos and was Daniel Young’s boss. Seth called
to mind Doc Brown from the 1985 Michael J. Fox movie Back to the
Future. He didn’t have Doc’s crazy white hair, but he sported a huge,
frizzy gray beard that gave him a similar mad scientist look. Though in
his late fifties, he still said “dude” a lot and became really animated
when he was explaining scientific concepts.
Seth had told Elizabeth about a math model called SEIR (the letters
stood for Susceptible, Exposed, Infected, and Resolved) that he
thought could be adapted to predict where the swine flu virus would
spread next. For it to work, Theranos would need to test recently
infected patients and input their blood-test results into the model.
That meant getting the Edison readers and cartridges to Mexico.
Elizabeth envisioned putting them in the beds of pickup trucks and
driving them to the Mexican villages on the front lines of the outbreak.
Chelsea was fluent in Spanish, so it was decided that she would head
down to Mexico with Sunny. Getting authorization to use an
experimental medical device in a foreign country is usually no easy
thing, but Elizabeth was able to leverage the family connections of a
wealthy Mexican student at Stanford. He got Chelsea and Sunny an
audience with high-ranking officials at the Mexican Social Security
Institute, the agency that runs the country’s public health-care system.
IMSS approved the shipment of two dozen Edison readers to a
hospital in Mexico City. The hospital, a sprawling facility called
Hospital General de México, was located in Colonia Doctores, one of
the city’s most crime-ridden neighborhoods. Chelsea and Sunny were
discouraged from going to and from the hospital on their own. A
driver dropped them off inside the gates of the facility every morning
and picked them up at the end of each day.
For weeks, Chelsea spent her days cooped up in a little room inside
the hospital. The Edison readers were stacked on shelves along one
wall. Refrigerators containing blood samples were lined up along
another. The blood came from infected patients who’d been treated at
the hospital. Chelsea’s job was to warm up the samples, put them in