From Tshumbe Sainte Mariee where I had worked as a medical students in 1951, Dr.Hemerijckx went to India where he started a large program of detection and ambulatory treatment of leprosy patients ( clinics under the trees ) in Polambakkam, South India, under the auspices of a new Foundation. They were in charge of 35,000 patients in the villages of the area. I proposed to Hemerijckx's successor, Dr.Claire Vellut, my classmate at the university, to try developing a mathematical model of the transmission of leprosy based on the excellent statistical data of this project. It was a huge enterprise, with retrieval of the individual data representing some 400,000 person-years of observation, transfer to punched cards, conceptualization of the model, writing special softwars, and forthcoming simulation of epidemiological indices, incidence and prevalence, according to operational variables such are delay for detection, segregation of the patients, vaccination (virtual since non existing), compliance to treatment. I got precious help from my research assistant, C.Misson, and his husband, an operation research specialist. The simulations' results were utilized to guide the research efforts, discuss actual data of the leprosy control campaigns, recommend allocation of resources.
In the 70ies, in the context of increasing world-wide leprosy control activities, it became indispensable to improve and standardize statistics on the registration of leprosy patients. As Collaborative Center of WHO for the Epidemiology of Leprosy, my department at the University was suggested by WHO to develop such a system. Under the appellation of OMSLEP Recording and Reporting System, it was translated into French, Spanish, Portuguese, Arabic, Chinese, tested in a number of countries, and accepted by many, We started then to regularly publish statistics, an activity taken thereafter by WHO