Pathogen challenge test

What we currently know about viral pathogenicity and the mechanism of viral latency represents only a small facade of what needs to be known, thereby resulting in a tremendous challenge in clinical testing. 

Britton There are notable examples of how one infection influences the responses to other pathogens, for example measles and TB. There are also intriguing data from west Africa where BCG immunization is associated with improved responses to other vaccines and reduced mortality from unrelated infectious diseases. This effect may not be seen in the north, but only in environments where there are multiple infectious threats occurring early on in life. This interaction is not readily analysed in animal models, but challenges us to develop relevant animal models to test these hypotheses. 

Challenge Microorganisms. The antimicrobial spectrum of activity of the test products must be broad, versus 25 ATCC strains of 20 species of bacteria and 2 species of yeasts listed in 333.470(a)(l)(ii) of the TFM, plus 25 fresh clinical isolates of these same species of bacteria and yeasts. The challenge microorganisms include members of normal flora in humans, common environmental contaminants, or systemic pathogens. 

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