See: Campbell MD Overcrowding Typhus
Bats, Mosquitoes and Dollars by Campbell, Dr. A. R., The Stratford Company, Boston, Mass., 1925.
"This child, although living in the same room with the patients at the Pest House, had not acquired the smallpox, after being exposed to it all of the time for a period of six weeks; yet upon the fifth day after returning home, this child acquired the initial fever. I then examined their house and found it to be literally alive with bedbugs."---CHARLES A. R. CAMPBELL, M. D.
"Assuming that bedbugs are the only diffusing agents of this loathsome disease, then our present knowledge of its being "air-borne," or of its being transmitted by fomites, must be all wrong, therefore the principal work here mentioned is the demonstration of its non-contagiousness by means of clothing, bedding, hangings --in short, fomites........Anita H., a Mexican child, four years of age, never vaccinated and who had never had the disease, was taken to the pest house, where she took a baby out of the crib and played with it about four hours, hugging and kissing it and riding it in a perambulator around the grounds; but, although this baby was covered with pustules of smallpox, and although we took no precautions whatever (the girl's mother having agreed to this experiment), the girl did not acquire the disease. P. H., a Mexican, vaccinated in infancy, who freely mingled with the smallpox patients in the discharge of his duties as night watchman at the pest house, keeping up the fires and remaining all night, did not contract the disease. A. C., decidedly strumous, never vaccinated nor had the smallpox, freely mingled with smallpox patients in all of the stages, playing cards with them, eating and sleeping in the infected tents, and has continued to do so for more than two years."---CHARLES A. R. CAMPBELL, M. D.