JF Ptak Science Books Quick Post
I was certain at first glance that this little pamphlet was referring figuratively to the Germans in Romania as "germs". Romania was a neutral country for a good part of WWI though it is my impression that they never warmed to the idea of Germany as a friendly non-combatant, and so they would treat them as you would turn away from someone's coughing fit.
This is not the case. They were talking about real microbes, and in particular, the bacterium Bacillus anthracis that some contingent of Germans was manufacturing in Bucharest, evidently with the intent to infect horses and mules that were on their way to the Russian front, a real nasty piece of business. Now the use of biological weapons had been around for perhaps thousands of years (in crude form), though in more recent times it wasn't much used at all, though there are notable exceptions (as with the Japanese against the Chinese during the Sino-Japanese war that was fought for seven years leading into WWII. The use of biological weapons had been outlawed at the Hague Conference, but that didn't necessarily stop everybody, as this pamphlet states. So the not-metaphorical microbes were not to be used, though poison gases of all sorts was an option.