A security guard in the dusty Nigerian city of Kano is living with tragedy -- a 14-year-old son whose dazed eyes, uneven gait and slow speech signal brain damage.
Mustapha Mohammed says he knows who to blame -- Pfizer Inc, the world's largest drug maker.
New York-based Pfizer is facing four court cases -- two filed by the federal government, two by the state in recent months -- in Nigeria over a decade-old drug trial that included Mohammed's son.
The company, which denies any wrongdoing, is accused of using a 1996 meningitis epidemic to push through a sloppily managed study without the full understanding of parents or proper regulatory approval, contributing to death in some and infirmities in others.
Whether Pfizer acted improperly, the fallout provides a case study of the ethical dilemmas that arise when Western medical priorities run into Third World poverty and ignorance. The communication gap between those handing out medical alms and those receiving has bred mistrust and anger in Kano -- with damaging, far-reaching effect.
In 2003, residents of Kano and the state of the same name boycotted a polio vaccine effort on charges that it was a Western plot to make Africans infertile. The Pfizer uproar has been cited as one reason for suspicion about Western medicine.
Without mass vaccination, polio exploded in Nigeria and eventually spread to 25 previously polio-free countries.
Though the meningitis epidemic is long over and the polio vaccination program is back on track, suspicions persist.
Mohammed is sure no one asked his permission to test a drug on his child. But he also wasn't asking many questions when he rushed his son to the hospital in 1996.
"We were desperate for drugs. We just took it in good faith," said Mohammed, who lives in a tiny house off a dirt road in one of Kano's poorer neighborhoods. Mohammed -- who can't read or write -- only later found out that the pink paper he kept with Pfizer's name and treatment dates meant his son had been in the study.
Pfizer says it explained the study to families using practices in line with US and international guidelines, even employing local, Hausa-speaking doctors and nurses. Written permission was obtained when possible, or oral consent if they were illiterate.
Across town, Abu Abdullahi Madaki can't be sure if her daughter Firdausi took part in the Pfizer study. Citing privacy concerns, Pfizer has declined to release the names of the 200 children it treated.
All Madaki knows is she took a feverish 8-month-old infant to the hospital in 1996, and now her daughter suffers severe brain damage that left her unable to sit up or talk.
Meningitis -- a brain infection -- leaves 10 percent to 20 percent of survivors with mental damage, hearing loss or learning disabilities, according to the WHO.
But Madaki said: "My younger sister had meningitis, but it was nothing like this. My younger sister is now a mother with children."
Madaki, who is illiterate, said she'd always felt that the hospital did something wrong, and decided when she heard about the charges against Pfizer on the radio that her daughter must have been in the study.
Pfizer says it brought the drug -- an antibiotic called Trovan -- to Nigeria as a humanitarian effort. Trovan had already gone through human trials in the US. It was a tablet, which could be easier to use with children than the standard meningitis treatment -- a painful injection.