To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Share Embed Share URL Video File Node URL Embed Code <iframe title="MRC TV video player" width="640" height="360" src="https://www.mrctv.org/embed/128303" allowfullscreen></iframe> Chris Matthews, who once served in the Peace Corps in Africa, doesn't know how to pronounce "dengue fever," a malady common throughout much of the continent.