In the middle of the second verse, Ron Isley goes down memory lane after saying "The down low happened to me all over again"; additionally, the third verse starts with Mr. Biggs asking R. Kelly "What the hell is going on between the sheets in my own home?

"Contagious" rose to number 19 on the pop singles chart and number 3 on the R&B singles chart and made the Isleys the first group to score a hit in six consecutive decades on Billboard's Hot 100.

In 2002, the song won a Soul Train Music Award for Best R&B/Soul Single, Group, Band or Duo.

R. Kelly makes a cameo in the 2003 follow-up song "Busted" that is told from the prospective of Mr. Biggs and his current partner.

In the video, he is seen returning the woman to Mr. Biggs's home before she is confronted about the affair.