Mello worked passionately to eradicate tuberculosis in Goa and malaria from Velha Goa. His efforts towards this end, led to the establishment of two important institutions, namely the first leprosarium in Asia at Macasẚna in Salcette in 1934, today known as Leprosaria Froilano de Mello and Dispensario Virgem Peregrina at St. Inez, Panjim. He also established the TB sanitarium in Margao in 1928 and opened a ward for those suffering from leprosy in Daman. In 1926, Mello with the help of one of his pupils, Dr. Luís Bras de Sa, carefully mapped the site of Old Goa and recognised more than 4,800 wells in the area, which were breeding grounds of anopheles mosquitoes. This led to the closure of these wells, and in turn, led to the reduction of the mosquito breeding sites. This factor played a significant role in curbing the Malaria epidemic in Goa in the 1920s.
