This poster would have been used to keep track of monthly VD cases. It features an image of a record book.
Source
National Archives, Record Group 112: Records of the Office of the Surgeon General (Army), Series: Posters Promoting Venereal Disease Prevention and the Prevention of Other Diseases, circa 1942-1944.
"In 1942 This Station Had: [Blank] Cases of Venereal Disease : Prophylaxis Taken Promptly After Exposure Would Have Prevented Them : Venereal Disease Helps the Enemy"
American Social Health Association Records (1905-2005), University of Minnesota, Social Welfare History Archives, Army Air Forces Training Command, circa 1940-1945, Box 177, Folder 26.