Itchy anus- can be due to pinworms. Thats how they spread. They lay eggs right outside and it itches, and then the eggs get on ones hands, and eventually back in the mouth.
Lung infection- maybe migrating worms. Many species first develop in the lung tissue and then crawl up only to get swallowed according to their life cycle.
My sister, who had recurring pneumonia, once used Colloidal Silver sprayed/inhaled to help clear up a persistent lung infection [after Antibiotics ] in only a few days.