More than a quarter of people surveyed in Ebola-hit areas of the Democratic Republic of Congo told researchers they do not believe the disease exists.
Some 36% of respondents also believed that the disease had been fabricated to destabilise the country.
The authors of the study said this mistrust was a factor in prolonging the epidemic.
The current outbreak started in August and more than 600 people have died, according to the health ministry.
More than 1,000 people have contracted the virus during the current outbreak, which is the second-largest ever recorded.
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