Transmission of leprosy
Tranmission by contact
The possibility of transmission of leprosy through the respiratory route is gaining increasing attention in recent years. It is interesting to note that as early as 1898 this possibility has also been discussed at some length by Schiffer (Schiffer, 1898). The possibility of transmission through the respiratory route is based on (a) the inability of the organisms to be found on the surface of the skin, (b) the demonstration of a large number of organisms in the nasal discharge, (c) the high proportion of morphologically intact bacilli in the nasal secretions, and (d) the evidence that M.leprae could survive outside the human host for several hours or days.
Transmission through insects
With the available evidence on intracutaneous inoculation as a successful method of transmission of M.leprae in the mouse footpad model and a similar situation possibly existing in human beings, the question arises whether insects could play any role in natural infection. Although a large number of experiments had been conducted in the past demonstrating AFB in biting insects, the question whether insects actually transmitted infection had remained unanswered.