Techniques to kill infective larvae of human hookworm Necator americanus in the laboratory and a new material safety data sheet

Abstract

With increasing experimental use of the human hookworm Necator americanus in therapeutic trials, an evidence based approach to laboratory safety is needed to produce an accurate Material Safety Data Sheet (MSDS). Five chemical disinfectants and hot water were evaluated for their killing effect on infective larvae (iL3) of N. americanus. The most effective chemical was 70% ethanol which achieved 100% kill in 10 min. Dettol® was also effective after 20 min. Formalin (10% concentration) had a slow killing effect while bleach (1% concentration) and glutaraldehyde (2% concentration) were ineffective. Infective larvae were killed by hot water at 80 oC or higher. In a simulated bench top spill 70% ethanol at five times the spill volume was 100% effective after 20 min. Addition of hot water was effective when the water was close to boiling, but did not kill 100% of iL3 at 80 oC.