k ▁group ▁of ▁the ▁country . ▁Second ▁phase ▁is ▁concentr ated ▁ep ide mic ▁when ▁proportion ▁of ▁inf ected ▁people ▁in ▁any ▁high - ris k ▁group ▁r ises ▁more ▁than ▁ 5 %. ▁Third ▁and ▁last ▁phase ▁of ▁ep ide mic ▁is ▁generalized ▁ep ide mic ▁when ▁pre val ence ▁of ▁H IV ▁in fection ▁r ises ▁over ▁ 1 % ▁among ▁blood ▁don or ▁or ▁pre gn ant ▁women . ▁Like ▁other ▁Asian ▁countries , ▁Pakistan ▁is ▁following ▁a ▁compar able ▁H IV ▁ep ide mic ▁tr end ▁having ▁moved ▁from ▁‘ low ▁pre val ence , ▁high ▁risk ’ ▁to ▁‘ con cent r ated ’ ▁ep ide mic ▁in ▁the ▁early ▁to ▁mid - 2 0 0 0 s . ▁Pakistan ' s ▁ep ide mic ▁is ▁primarily ▁concentr ated ▁among ▁two ▁of ▁the ▁key ▁population ▁groups ▁driving ▁the ▁ep ide mic ▁in ▁the ▁country . ▁These ▁are ▁people ▁who ▁inject ▁dru gs , ▁with ▁a ▁national ▁pre val ence ▁of ▁ 2 7 . 2 % ▁( weight ed ▁pre val ence ▁of ▁ 3 7 . 8 % ); ▁followed ▁by ▁trans gender ▁sex ▁workers , ▁standing ▁at ▁ 5 . 2 % ▁and ▁then ▁ 1 . 6 % ▁among ▁male ▁sex ▁Work ers . ▁The ▁pre val ence ▁in ▁female ▁sex ▁workers ▁still ▁remains ▁low ▁at ▁ 0 . 6 %. ▁The ▁ge ographic ▁tr end ▁of ▁key ▁populations ▁is ▁from ▁major ▁urban ▁cities ▁and ▁provincial ▁capit als , ▁expand ing ▁over ▁time ▁to ▁smaller