PON1 and parasitic infectious disease: The effects of the second most common parasitic infections caused by nematodes on PON1 activity were studies by Farid et al. [92,93] who showed that infection by Nippostrongylus brasiliensis, a gastrointestinal nematode that infects mice and rats and has a similar life cycle as human pathogens Ancylostoma duodenale and Necator americanus[133], reduces serum PON1 activity in male rats.