"I have this thought, if he had received say five or six doses, he would have been immune from this ailment," Kanduwa said.
He says Isa received two of the oral polio vaccinations. Painfully close to the four doses recommended for complete immunity.
In a district that now has an immunization rate of around 85%, officials hope Isa's will be Nigeria's last new case of polio. More than a year of being polio-free highlights how close the country is to a major milestone. But Isa's case also shows just how difficult polio can be to fully eradicate.
Standing outside of the clinic, Kulchumi Hammanyero from the World Health Organization smiles when she sees the line of mothers with babies in their laps and immunization cards in their hands, waiting patiently for the vaccine. But her smile is matched by a heavy dose of caution.
"When we see there is no more wild polio virus (WPV) and all indicators are showing us that we have covered the necessary ground, then we can say, ok, we have reached a certain point. But we are not out of the woods, not out of the woods at all," Hammanyero said.
For Hammanyero and her colleagues from government and partner organizations, eradicating the disease means traveling to the furthest and hardest to reach corners of Africa's most populated country.
With coverage rates higher than many places in the world, complacency is now the campaign's biggest enemy. It will be at least another two years before Nigeria can be officially certified polio free. Two more years of complete community and government buy-in needed.
Nigeria is one of three countries, along with Afghanistan and Pakistan, where population density and poor sanitation, coupled with insecurity in the region and threats against healthcare workers, allowed a virus all but forgotten in most of the world to flourish.
"Better healthcare and better security are absolutely linked," said Gates Foundation CEO Sue Desmond-Hellmann.
The Gates Foundation has contributed billions toward Nigeria's polio-eradication campaign, and Rotary International, the U.S. Centers for Disease Control and Prevention, the WHO and UNICEF have all been working to end the disease as part of the Global Polio Eradication Initiative
The last push will be a challenge, Desmond-Hellmann says, but by no means an excuse.
"How do we work with community leaders, religious leaders, to ensure that we reach every child, no matter where they are? Because we believe all lives have equal value," she said.