DAKAR, Senegal — Nearly one-third of Africans surveyed say they have been forced to pay bribes including for medical treatment, according to a 34-nation poll released Wednesday.
The Afrobarometer survey also found it was often the poorest people in each country who pressured to pay bribes at health clinics and hospitals.
The West African nation of Sierra Leone fared the worst overall, with 63 percent of respondents saying they’d paid up at least once in the previous year. Morocco and Guinea came next, each with 57 percent.
‘‘Corruption is a cancer which has spread nationwide,’’ said Onesimus Johnson, an analyst in Sierra Leone where bribes are known as a ‘‘put for me.’’ More than 69 percent of citizens polled there said that most or all police were corrupt.
In Guinea, the culture of corruption dates back to the decades of dictatorship that enriched its ruler and his associates. The West African country held its first democratic presidential election in 2010.
Medical treatment was the second most common reason cited after paying off officials to obtain a document or permit, said Richard Houessou, who headed the Afrobarometer project.