Reaction of the Human Body Louse

Abstract

Summary and Conclusions

Contrary to general belief, the experiments reported above indicate that guinea pig blood per se is not toxic to the human body louse.

In the first experiment it was demonstrated that the red blood cells of guinea pigs remain undigested in the gut of the louse.

In the second experiment it was shown that lice starved for an average period of 36 hours and then fed once on a guinea pig, die within 72 hours, apparently of starvation. Control lice fed only on human blood, likewise were found to die 4 to 4 1/2 days following their last human blood meal.

In the third experiment it was shown that lice fed once on guinea pig blood live their normal life span when their daily feedings are continued subsequently on human blood.

It would appear that human body lice secrete a digestive enzyme specific only for human red blood cells which makes it impossible for them to digest guinea pig blood.