Density and distribution of Clostridium tetani in the soil.

Clostridium tetani or its toxin was recovered from a minute amount of soil samples collected on the surface of the ground of various places. C. tetani was recovered from 10% and tetanus toxin alone from another 1% of soil samples employing 1 mg of the soil. C. tetani or its toxin alone was recovered, employing 1 mg or more of soil, from the wet shores of ponds and rivers, fields and rice fields (85%), the yards of farmers and non-farmers (53%), school and hospital grounds (30%) and on the roadside (20%). Two tetanus patients were injured in their yards where 1 mg soil samples yielded C. tetani. 12 of 13 soil samples collected at the yard of one of these patients at 3 different times yielded C. tetani. C. tetani did not remain at the same place in the same quantity. It was isolated more readily from the soil samples collected on the surface of than deep in the ground.