Pakistan, Aug. 13 -- If you want to know whether Pakistan is winning against polio, don't ask a podium. Last month, the National Institutes of Health found poliovirus in 42 of 117 processed sewage samples drawn from 87 districts with ten more samples still in the lab.

Compared with June's 32pc, that is a movement in the wrong direction. Sewage is evidence. And the evidence says the virus is circulating widely.

Sindh carried the heaviest load, with 19 of 29 sites positive, Punjab 12 of 27, and KP seven of 31; in Islamabad, three out of four sites lit up. Balochistan posted one positive this month, but anyone reaching for a victory lap should remember how quickly trajectories flip when refusal belts and missed-child pockets are left to fe...