In August 2015, the same month that Dr Vanessa saw her first case of microcephaly related to Zika, my own daughter was sent for a brain scan.

She was eight months old and no trouble at all. Whereas her brother had been a difficult, colicky baby, Katy would sit quietly in her bouncy chair, her hands folded demurely together.

But while the other babies born around the same time began to interact with the world around them – gurgling and smiling, grasping rattles and sitting upright – Katy’s babyhood seemed to drift on throughout that summer. She didn’t smile or fix on things clearly with her eyes. She didn’t reach out for objects, and, for a long time, she couldn’t support her head.

I will never forget how tenderly the hospital paediatrician examined her, his hands gently pressing her tummy, folding her legs onto her.

The morning after the brain scan, he called us back into the hospital on the pretext of needing to redo a blood test. “To be honest, the scan was not completely normal,” he said when we got there. He pointed at the image on his computer screen – an apple-shaped black-and-white cross-section of our daughter’s brain – and said the black areas were too large, and the white areas were too small.

Katy was diagnosed with ventriculomegaly, meaning there was too much fluid and not enough brain. Later, the neurologist added a diagnosis of microcephaly. The pregnancy and birth had been quite normal, so the doctor surmised that Katy probably had an underlying disease, and warned that our son might have it too.

We knew, at least, that it wasn’t congenital Zika syndrome because we hadn’t been travelling in the affected areas. It was to be another two-and-a-half years before we learned that Katy’s condition was caused by a rare genetic disorder and that our son is unaffected.

But that first winter was miserable. Katy didn’t laugh or smile.

We couldn’t leave the house with her because it was too cold, and our buggy did not support her floppy little body. She couldn’t master the complicated chain of movements required to swallow, and we didn’t have the right chair to feed her properly. She was constipated and angry, and my head was filled with thoughts of her death.

In the evening, our screens were filled with images of Brazil’s microcephaly babies. I thought: "How much harder would it be if our private ordeal was an international news story too?"