The researchers also found genes from parasites, fungi, and viruses, in both healthy hives and in those which had undergone collapse. But IAPV only appeared in samples from CCD populations.
Even if a primary culprit has been found, this doesn't mean that there is a cure to the problem, although it certainly helps in finding one.
UPDATE via Science News:
IAPV was detected in 83 percent of samples of bees from faltering colonies but in only 5 percent of samples from colonies without symptoms . . . . The bee analysis included two fungi that have been suspects in colony collapses. Nosema ceranae and Nosema apis occurred in 90 percent and 100 percent, respectively, of samples of sick colonies, says the Lipkin team, but also in 72 percent and 92 percent, respectively, of symptomfree colonies.
Study author Diana Cox-Foster of Pennsylvania State University in University Park "suspects that bees become susceptible to the virus only when weakened by some other factor, such as pesticide exposure."