According to Parasites in Humans, about 22 million people in Africa, South and Central America, and Asia are infected by human lung flukes (trematodes), which are parasites that commonly live in the lungs. In severe cases, lung flukes can travel to the spinal cord, causing paralysis, or to the heart, which can result in death. The parasite is most commonly found in seafood, and if ingested it will gnaw its way through the intestines and into the lungs, where its life cycle is completed. Flukes can also live in the blood, intestines and liver.
One of the most common symptoms of lung flukes is coughing, which may begin as a dry heaving cough and progress to severe coughing with red flakes of blood.
Patients may notice severe chest and abdominal pain as a result of inflammation. They may attribute this pain to coughing when it is fact a result of the parasitic infestation.
Although many lung parasite infections go unnoticed, more severe cases may result in a low- to high-grade fever.
Lung flukes may cause diarrhoea. One way to detect lung flukes is to test faeces of patients who display symptoms; they often travel into the intestines and make their way out of the body.
Those who suffer from frequent cases of pneumonia and bronchitis might consider being tested for lung parasites, which often contribute to the development of these conditions. They can also contribute to the development of lung abscesses.