Islamabad: Massive return of expelled Afghan nationals is bringing poliovirus back, as over 40 percent of Pakistan’s detections in two months were linked to Afghanistan, where 50 polio cases were reported against nine in Pakistan, officials said on Friday.
Officials said Afghans who had been sent back are reportedly returning in large numbers through sporadic crossing points in Balochistan and Khyber Pakhtunkhwa (KP) and moving across the country, making this the biggest concern for polio eradication.
Afghan-linked poliovirus has been found as far as Jamshoro district in Sindh while all three polio cases reported from Khyber district this year are also linked to Afghanistan, according to PEI and World Health Organization (WHO) officials monitoring both countries.
The Pakistan Polio Eradication Initiative (PEI) said the share of Afghan-linked detections stood at about 50 percent in September and 40 percent in October, showing that the threat from across the border has not eased.
Pakistan’s ninth case of 2026 was confirmed this week in a seven-month-old boy from Bara tehsil of Khyber district.
Of Pakistan’s nine cases, seven are from KP, four from southern districts and three from Khyber, while two are from Sindh.
Afghanistan’s outbreak is far larger. The WHO and Afghan ministry of health data show 50 cases this year across 12 provinces, with Hilmand reporting 12, Kandahar 11 and Nangarhar 10. These three provinces alone account for 33 cases, or two-thirds of the total.
Baghlan and Hirat have reported three cases each, Farah, Kabul, Kunar and Nuristan two each, while Logar, Paktika and Uruzgan have reported one each.
The virus has also been found far from the border. According to the PEI, 29 positive sewage samples collected in Pakistan between January and October have been linked with Afghanistan. Balochistan accounts for 14 of them, KP for nine, Sindh for four and Punjab for two.
In Balochistan, 11 samples were from Quetta, two from Chaman and one from Zhob. In KP, six were from Peshawar, two from Khyber and one from North Waziristan. In Punjab, one each was from Rawalpindi and Multan. In Sindh, two were from Karachi’s Keamari district, one from Jamshoro and one from Karachi East. Seven of the 29 samples were collected in October alone, including three each in Quetta and Sindh.
The PEI listed Peshawar and Khyber, the Quetta block, Zhob, Karachi, and Rawalpindi and Multan in Punjab as the main affected districts.
The WHO describes Pakistan and Afghanistan as a single epidemiological block, meaning transmission in one country puts the other at risk. Health experts blame poor-quality vaccination drives in Afghanistan for the explosion in cases.
The WHO has raised concern over restrictions on house-to-house campaigns, particularly in southern provinces, where vaccination has largely been carried out at fixed sites, leaving infants and children in remote communities unprotected.
Pakistan’s own figures show steady progress. Cases fell from 74 in 2024 to 31 in 2025 and nine so far this year, while the country has cut polio cases by 99.8 per cent from an estimated 20,000 a year in the early 1990s. However, Afghanistan has reported more than five times as many cases as Pakistan this year, and officials warned that progress could be reversed if the virus keeps crossing the border.
The PEI said Khyber district faced security constraints and previous campaigns had left children unreached because of access barriers. Routine immunisation in several districts is also below the required level, leaving children vulnerable.
A door-to-door vaccination campaign is under way from November 2 to 8 in 97 districts, including Khyber, to protect nearly 24 million children under five. The campaign is being synchronised with Afghanistan. From October 26 to 31, a targeted injectable polio vaccine campaign in 78 union councils of the Peshawar block reached 829,000 children up to the age of 10.
The PEI said it had launched a comprehensive investigation of the Khyber case and was finalising a science-based response, while measures to strengthen routine immunisation and sustain access in affected areas were being considered.
It urged all parents to ensure that every child under five receives the polio vaccine in every round, regardless of previous doses.
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