Via The New York Times, an excellent long article: How a Medical Mystery in Brazil Led Doctors to Zika. The introduction:
Something strange was happening last August in the maternity wards of Recife, a seaside city perched on Brazil’s easternmost tip, where the country juts into the Atlantic.
“Doctors, pediatricians, neurologists, they started finding this thing we never had seen,” said Dr. Celina M. Turchi, an infectious diseases researcher at the Oswaldo Cruz Foundation, a prominent scientific institute in Brazil.
“Children with normal faces up to the eyebrows, and then you have no foreheads and very strange heads,” she recalled, referring to the condition known as microcephaly. “The doctors were saying, ‘Well, I saw four today,’ and, ‘Oh that’s strange, because I saw two.’”
Aside from their alarming appearance, many of the babies seemed healthy.
“They cried,” Dr. Turchi said. “They breast-fed well. They just didn’t seem to be ill.”
Doctors were stumped.
They did not know it then, but they were seeing the first swell of a horrifying wave. A little-known pathogen — the Zika virus, carried by mosquitoes — had been circulating in Brazil for at least a year. It would later become the chief suspect in the hunt to work out what had happened to those newborns.