It was more likely that the virus was still present but had retreated to undetectable levels in mr stimpson ' s blood 这更象是病毒依然存在，只是血液中病毒的量已经少到检测不出的水平。
2.
Professor grulich said it was possible mr stimpson was a " slow progressor " and that he " could develop aids in 17 years or 20 years instead of 10 years " 在感染的初期，病毒载量有时会有很大波动，从很高到很低，他说： “病毒完全查不出是不寻常的，但也不是没听说过。 ”
