Hydatid Disease (Part V), wherein we finally explain why it makes you sick.
It takes years for symptoms to show up. Oh, but when they do....
The growing cyst puts pressure on the liver, producing symptoms of obstructive jaundice and abdominal pain. If the cyst ruptures into the biliary tree (the collection system of bile in the liver), severe, possibly life-threatening inflammation along with intense pain and jaundice.
The most serious problem, though, is the rupture of the cyst. This occurs in 50-90% of the cases. It can cause anaphylactic shock, which is life-threatening.
The presence of hydatid cysts in the lungs can cause chest pain, difficult breathing, or rupture. If a cyst is larger than 2 inches in diameter, it will compress airways.
Secondary infection can occur, as can pneumothorax, a condition where air fills the chest outside of the lungs, impeding their ability to expand. Cough and chronic wheezing can develop. And as with hepatic (liver) cysts, acute rupture carries the risk of anaphylaxis.
What to do?
Prevention is always best, right? It turns out that while avoiding hydatid disease is straightforward--don't let dogs eat sheep offal, practice good hygiene, administer antiparasitics to dogs on a regular basis--the elimination of hydatid disease is not all that easy. New Zealand, a island nation and therefore naturally having a distinct advantage when trying to eradicate diseases, still took 20 years to rid itself of hydatid disease. This is in a modern, developed nation with strong public health laws and enforcement, not to mention a sheep industry that coordinated to get behind the effort. Less developed countries that complained of high prevalence of hydatid disease 30 years ago are still struggling with the same levels of infestation. Wales, a country that thought that its hydatid days were over, recently found the parasite again.