Watch BBC Bodysnatchers online: Episode 3 Microparasites

In November 2002, John and Lucinda were visiting New York when they were admitted to the Beth Israel Medical Centre after John fell seriously ill. A reporter dispatched to the hospital described their situation as something most doctors had never seen, something that hadn’t been reported in New York in over a century. John and Lucinda had been put in isolation after exhibiting classic symptoms of bubonic plague. The final episode of BodySnatchers deals with the most deadly form of parasite, the micro-parasite. To the untrained eye, they are the simplest of all organisms – tiny, single-celled, and invisible. In reality, they are infinitely complex, highly adapted and absolutely lethal. From tuberculosis to the Black Death, the micro-parasite has spread a trail of havoc across the planet, being responsible for untold millions of deaths.

click here to see where to watch or .