Blood tests might have shown antibodies to the virus, meaning the birds had been infected but survived.

Over 15% showed antibodies to yellow fever and more human cases quickly followed.

"If anyone shows antibodies to Taenia solium, then this theory is more than just a house of cards."

A blood test that shows antibodies to HSV-1 means you could have genital or oral herpes.

Only one shows antibodies, and he isn't really symptomatic.

A test when the baby was 3 months old showed antibodies to the AIDS virus.

More than 90 per cent of pregnant women show antibodies to varicella-zoster virus, which means they've had the infection in childhood, sometimes without realising it.

The auto dealer's wife shows antibodies, but no symptoms as yet.

"Three or four days until he starts showing antibodies, probably."

No, he'd been exposed by sexual contact only, and now his blood was showing antibodies, too.