The cumulative effect of flooding in both 2008 and 2009, in combination with the low levels of resilience, increased the levels of vulnerability especially for the large proportion of the population affected by human immuno-deficiency virus (HIV) and Acquired Immuno-deficiency Syndrome (AIDS) (Namibia has one of the highest prevalence rates in the world, estimated in 2008 at 17.8% of the adult population).