There are certain species of flukes that are capable of triggering lung fluke infections specifically the Paragonimus westermani which triggers paragonimiasis. An individual can acquire lung fluke infections if cysts that contain immature flukes are ingested in raw, poorly cooked or pickled freshwater crayfish or crab.
Once the cysts are ingested, the larvae move out of the cyst and embed on the intestinal wall and enter the abdominal cavity. They go within the diaphragm and occupy the lungs where they develop into adults and release eggs. The worms can also reach the liver, brain, skin, lymph nodes or spinal cord and develop there. Nevertheless, the life cycle could not be completed since the eggs have no way to exit the body.
From the lungs, the eggs are passed into the sputum that is being coughed up or swallowed and passed in the stool. In case the eggs gain access to fresh water, they develop into larvae that are consumed by snails. Within the snail, they mature into a variety specifically called as cercariae that is capable of swimming. The cercariae that were released by infected snails infect crayfish or crabs and form cysts.
What are the indications of lung fluke infections?
Once an individual has been infected, he/she might develop symptoms such as:
- Abdominal pain
- Diarrhea
- Itching
- Cough
The infection damages mainly the lungs, but might also affect other organs. The individual might slowly develop symptoms such as chest pain, chronic cough and difficulty breathing. In addition, the individual might even cough up blood.
If the brain is involved, the individual can experience seizures, visual issues or difficulty using or understanding language. Additionally, the individual might be paralyzed.
How is it diagnosed
The doctor will identify liver fluke infection if eggs are present in the stool or sputum. Oftentimes, a sample of fluid is removed from the lungs and analyzed for eggs. The blood tests are used to detect antibodies to the parasite. Other tests such as CT scan or X-ray might be required to check for any damage to the lungs or other organs.
Prevention
Those who are planning to travel to areas where these infections are common should take into consideration preventive measures. It usually involves avoiding raw or undercooked freshwater crayfish and crabs.
Management
The liver fluke infections are managed using praziquantel. It works by eliminating the flukes from the body. Other alternatives include bithionol or triclabendazole. Oftentimes, surgery is required to get rid of the outgrowth on the skin or even cysts in the brain in rare cases.