When Otto Treffers was born on 22 February 1892, in Oosterhout, North Brabant, Netherlands, his father, Pieter Jacobus Treffers, was 40 and his mother, Hendrika Wilhelmina Ferdinanda Roth, was 42. He married Ida Agnes Josephine Brockmoller on 11 September 1919, in The Hague, Hollande, Netherlands. In 1919, at the age of 27, his occupation is listed as east indian officer in 's-Gravenweg, South Holland, Netherlands. He died on 6 October 1944, in Sumatra, Indonesia, at the age of 52.