What's the plural form of onchocerciasis? Here's the word you're looking for.
Answer
The noun onchocerciasis can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be onchocerciasis.
However, in more specific contexts, the plural form can also be onchocerciases e.g. in reference to various types of onchocerciases
or a collection of onchocerciases.