Prevalence and Incidence of River Blindness
River Blindness: Rare Disease
River Blindness is listed as a "rare disease" by the Office of
Rare Diseases (ORD) of the National Institutes of Health
(NIH). This means that River Blindness, or a subtype of River Blindness,
affects less than 200,000 people in the US population.
Ophanet, who are a consortium of European partners,
currently defines a condition rare when if affects 1 person per 2,000.
They list River Blindness as a "rare disease".
More information about River Blindness is available from Orphanet
About prevalence and incidence statistics:
The term 'prevalence' of River Blindness usually refers to the estimated population
of people who are managing River Blindness at any given time.
The term 'incidence' of River Blindness refers to the annual diagnosis rate,
or the number of new cases of River Blindness diagnosed each year.
Hence, these two statistics types can differ:
a short-lived disease like flu can have high annual incidence but low prevalence,
but a life-long disease like diabetes has a low annual incidence but high prevalence.
For more information see about prevalence and incidence statistics.