Polio Cases in Pakistan 2018 — Twelve Cases Before the Reversal

Pakistan recorded 12 wild poliovirus cases in 2018. On the surface it was another very low year, marginally above 2017's eight. In hindsight it was the last quiet year before the programme's worst reversal in a decade.

The warning signs

Three indicators were already deteriorating during 2018, even while the case count stayed in single figures.

• Environmental positivity was spreading. Sewage samples were testing positive for wild poliovirus across an increasing number of cities, including districts with no reported cases. Environmental surveillance sees transmission long before paralysis does, and it was signalling that the virus was more widely distributed than the case count implied.
• Refusals were rising. Community resistance was hardening in specific neighbourhoods of Peshawar, Karachi and Quetta, in some cases organised rather than individual.
• Campaign fatigue. After years of repeated rounds, both households and frontline teams were showing the effects — more "not available" children, more houses marked covered without the child actually being vaccinated.

Where cases occurred

The 2018 cases came from the familiar reservoirs: Khyber Pakhtunkhwa and the tribal districts, Balochistan around the Quetta block, and Sindh. The geographic footprint had not changed since 2016 — which was itself part of the problem, because it showed that the hardest districts were not being permanently cleared, only suppressed.

What happened next

In April 2019 a false rumour in Peshawar — that schoolchildren had fallen ill after receiving polio drops — triggered mass panic, a campaign suspension, and a collapse in public confidence that spread nationally within days. Cases rose from 12 to 147 in a single year.

The 2018–19 sequence is why the programme now treats community trust as core infrastructure rather than as messaging, and why the engagement work described in Muslim ulema dispel misconceptions and in the field stories archive receives the attention it does.

For the complete year-by-year record see polio cases by province.