Zimbabwe suffered occasional outbreaks of acute diseases (such as plague in 1994). The gains on the national health were eroded by structural adjustment in the 1990s, the impact of the HIV/AIDS pandemic and the economic crisis since the year 2000. In 2006, Zimbabwe had one of the lowest life expectancies in the world according to UN figure—44 for men and 43 for women, down from 60 in 1990, but recovered to 60 in 2015. The rapid drop was ascribed mainly to the HIV/AIDS pandemic. Infant mortality rose from 6% in the late 1990s to 12.3% by 2004. By 2016 HIV/AIDS prevalence had been reduced to 13.5% compared to 40% in 1998.