Post on 16-Dec-2015
Necator americanusReaction after penetration of
infective larvae (iL3)
Prof Rick Speare
Tropical Health Solutionsrickspeare@gmail.com
22 July 2012
101 iL3 have been placed on a pad under a bandage on the ventral surface of the wrist*
• Itching starts within 2 mins as iL3 begin to penetrate the skin
* 101 iL3 was too high!
12 hr post-infection
• Penetration site is itchy• Indistinct areas of erythema visible
1 day post-infection
• Erythema has increased• Papules are forming
2 days post-infection
• Multiple papules formed• Coallesced due to the large number of iL3 used
4 days post-infection
• Papules are increasing in size still
6 days post-infection
• Some papules are starting to vesiculate
7 days post-infection
8 days post-infection
9 days post-infection
10 days post-infection
• Vesiculation progresses
11 days post-infection
• At last! Signs that the lesions will disappear!
12 days post-infection
15 days post-infection
20 days post-infection
• Three weeks for the penetration reaction to resolve is 3 times longer than normal
Useful sources
• All images were original made by Rick Speare
• For additional information on experimental infections:
• Croese J, Speare R, Wood M, Melrose W. Allergy controls the population density of Necator americanus in the small intestine. Gastroenterology 2006;131(2):402-409.
• Croese J, Speare R. Intestinal allergy expels hookworms: seeing is
believing. Trends in Parasitology 2006;22(12):547-550.• Hookworms at Tropical Health Solutions