The answer was that in Burundi, having a clean bill of health has taken on a very particular meaning: unless and until you have paid for your hospital treatment, you simply can't leave, you are in effect a captive.
Comet: A comet is a relatively small solar system body that orbits the sun. When close enough to the Sun they display a visible coma (a fuzzy outline or atmosphere due to solar radiation) and sometimes a tail.
