Paragonimus lung fluke, light microscopy
Light microscopy showing a lung fluke (Paragonimus sp.), a type of parasitic flatworm that causes the disease paragonimiasis in humans. Symptoms initially involve the digestive system before the fluke migrates to the lungs. Here it can cause a cough, blood in the phlegm and chest pain. In around 25% of cases the flukes can then infect the brain which can lead to seizures, vomiting and headaches. It is caught from eating undercooked crustaceans, and is particularly prevalent in rural communities in east Asia. Filmed in Vietnam in 2008.