Lepra bacilli are mainly transmitted by

Ans. b (Droplets). (Ref. Ananthanarayan, Microbiology, 6th/pg.361)LEPRA BACILLI# Acid-fast bacilli, but less acid fast than TB bacilli.# H2SO4 used for decolorization of lepra bacilli (5%) is of less concentration than that for TB bacilli (25%).# Virchow lepra or foam cells in which globi of bacilli occur are large undifferentiated histiocytes.# Leprosy is exclusive human disease and patients are the only source of infection.# Very large numbers of bacilli are shed in nasal secretions (107/day), hence droplet is important mode of spread.# Mode of entry: Respiratory tract or through skin.# IP: 2-5years (few years to 30 days)# Not a highly communicable disease.# Prevalance in MH (1971 census) >> 5-8 cases per 1000 population.# Total no.of patients in India--4 million.