The health ministry ordered a vaccination campaign across the capital after the three-year-old was diagnosed.
Polio remains endemic in Afghanistan, Pakistan and northern Nigeria, but has been almost wiped out around the world.
In all three countries Islamic extremists have obstructed
health workers, preventing polio eradication campaigns from taking
place.
Since the Afghan Taliban changed their policy, allowing
vaccination in recent years, there has been a decline in cases in
Afghanistan.
There were 80 cases in 2011, 37 in 2012, and 14 in 2013.
The emergence of a new case in Kabul is worrying health officials.
It was discovered in a very poor community of Kuchis,
formerly nomadic herdsmen, now settled on a hillside in the east of the
capital.
In response, health workers have tried to visit every home in the community.
There is no running water or electricity, and some of the ex-nomads still live in tents, despite the cold of winter in Kabul.
Children from Kabul's poor Kuchi community have now been vaccinated against the disease
Once the workers have put drops into the mouths of infants they
find, they mark their hands with a blue line, and write the date on the
wall.
It seems rudimentary, but tens of thousands of volunteers in
campaigns like this across the country have succeeded in almost beating
the disease.
Cross-border transmission
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