A pre-history of the morphological index

The article deals with an over-looked period in the modern history of leprosy, namely the first decades of the 20th Century. The introduction of soluble derivatives of traditional chaulmoogra and hydnocarpus oils for parenteral treatment was received with optimism by physicians working independently in American Hawaii and by Leonard Rogers in colonial India. They reported similar after-treatment clinical and bacteriological phenomena, but stopped short of meaningful investigation of the latter. The pioneering studies of Froilano de Melo in Portuguese Goa on quantification and interpretation of changes in bacterial morphology in stained slides are described, as also the conflict with Rogers's ideas. de Melo's three-fold 'HMG” morphological classification presaged Ridley's 'SFG' Index of five decades later. That ambiguities regarding bacterial viability based solely on morphology in stained smears, which were pointed out by de Melo, were later confirmed in the mouse foot-pad model.