My situation is somewhat different; nothing so straight-forward as a
latrine.  I have a  vent that was used for years to circulate air
through a ship.  I know from the occupants that they had problems with
"crabs."  There may have been other problems as well.  I am wondering
what (if anything) can be done with air-borne deposits.  Large amounts
of hair, thread, string, and other very light fraction is present.  Is it
possible by examining hair, for example, to find the eggs of lice?  What
else might be possible?  What about the dust fraction?  I joke about it
being defoliated  human skin, but even that may be possible.  Is there a
way to test for such?
 
In summary, my situation is that I have air-borne deposits and am unsure
about its potential.  Has there been any work done with such?  And if
not, what would you say is its potential?  And finally, is there any
special treatment/handling that this material should be accorded either
in collection or storage?