Answer: Probable Strongyloides stercoralis larvae
Higher magnification would be needed to confirm the characteristic features of S. stercoralis filariform larvae (the stage that migrates to the lung during autoinfection). However, the overall appearance and clinical presentation is most consistent with strongyloidiasis hyperinfection.
To answer my question about the last photo - this does not represent a parasite, but might represent a fiber with proteinaceous debris. I was curious to see what others had to say, but no one commented.
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