AFTER CLINIC, GWEN FOUND a message in her mailbox. Charlie Sawyer from the CDC called. She had met Charlie the previous spring at a meeting in Atlanta and learned he was seeking collaborators to field test an assay he was developing to diagnose HTLV-III infection. As the assistant director of the AIDS program at City Hospital, Gwen had access to hundreds of AIDS and ARC patients getting routine blood draws who would be willing to donate an extra tube for research. She eagerly agreed to help.
Gwen had another agenda in joining the project. Since her needle-stick, whenever she had a cold or was tired, the fear she might be infected had to be dealt with or suppressed, usually the latter. Checking her lymphocyte count, which she did on each equinox and solstice for good luck, and seeing a robustly normal number made it easier for her to believe she had dodged the bullet, but it wasn’t definitive proof. In June, after listening to Charlie’s caveats about the assay’s accuracy problems, Gwen sent him a sample of her serum. Ten days of tension, punctuated by panic attacks, ensued before she received the result—HTLV-III antibodies not detected.
Charlie had warned her that the test was still a work in progress. Her result could be a false negative. He promised to check her serum again once the improved accuracy of his next generation assay was verified. She had told Rick the news with restrained optimism. Charlie had also talked her into enlisting health care workers at City Hospital as study subjects. Their samples would be run the moment his new version was validated.
Gwen dialed the number in Atlanta. Charlie answered and excitedly told her his next generation assay was ready for prime time. He was packing test kits to ship to her as they spoke. The City Hospital staff’s specimens she had stored in a basement freezer could finally be thawed.
“Charlie,” she asked awkwardly, “can I send you my serum now? I mean it would be weird to run it in our lab.”
“That’s not necessary.”
“I don’t understand. You said…”
“Gwen,” he interrupted, “I saved an aliquot of the serum you sent me in June. I already ran it with the new assay so you wouldn’t have to wait for the results like last time. I can guess how that must feel. Anyway, you’re not infected.”
Gwen was mute as she absorbed the news.
“This version of the assay has a less than five percent probability of false negatives, Gwen. And because you were antibody negative before, even though it was using a less accurate test, the probability is actually way, way lower because of the multiplicative... I don’t think you want a statistics lecture right now. Suffice it to say you are not going to get AIDS.”
Gwen had the presence of mind to thank him, which she kept repeating until he begged off.
“I’ll get back to you in a month. We want to follow those City Hospital results very, very closely.”