“ETHICALLY IMPOSSIBLE” STD Research in Guatemala from 1946-1948 
Table 3: Timeline of all Guatemala Experiments 
Feb. NIH Syphilis Study Section recommends STD research in 
Guatemala 
Mar. National Advisory Health Council meeting that approved the 
proposal that became “Research Grant No. 65 (RG-65)” 
Apr. PASB starts project 
Aug. Dr. Cutler arrives in Guatemala 
PASB officials sign agreements with the Guatemalan government 
Army Treatment programs begin 
Penitentiary 
Nov. Penitentiary Serology Studies begin 
Dec. “The Surgeon General [Parran] has become keenly interested in 
the Guatemala project.” 
1947 
Feb. 
Army 
Gonorrhea 
First intentional exposure experiment 
Dr. Arnold visits Guatemala 
Apr. 
Drs. Mahoney, Heller and Van Slyke visit Guatemala 
New York Times says human intentional infection syphilis 
experiments “ethically impossible” 
Army 
Gonorrhea 
First artificial inoculation (deep inoculation) experiment 
May 
Penitentiary 
Syphilis 
First normal exposure experiment involving sex workers 
Hospital 
Syphilis 
First artificial inoculation experiment 
Penitentiary 
Syphilis 
First artificial inoculation experiment 
School children 
Serology 
Studies begin 
Orphanage 
Serology 
Studies begin 
June 
Dr. Cutler concerned that the wrong person finding out about the 
experiments “might wreck it or parts of it” and proposes to start 
sending “barest summaries of our progress” to PASB 
Aug. 
Hospital 
Syphilis 
First abrasion experiment 
Sept. Dr. Mahoney tells Dr. Cutler that the abrasion methods are 
“drastic” 
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