New insights into the kinetics and variability of egg excretion in controlled human hookworm infections.

Four healthy volunteers were infected with 50 Necatoramericanus infective larvae (L3) in a controlled human hookworm infection trial and followed for 52 weeks. Kinetics of fecal egg counts in volunteers was assessed with Bayesian multi-level analysis, revealing an increase between weeks 7 and 13 followed by a plateau at about 1000 eggs per gram feces. Variation in egg counts was minimal between same day measurements but varied considerably between days, particularly during the plateau phase. These analyses pave the way for the controlled human hookworm model to accelerate drug- and vaccine efficacy studies.