Beginning in 1962 Pierre Collart and his group at the Fournier Institute in Paris stirred up a small hornets' nest not many people seem to have been interested at the time they announced that active spirochetes may persist in the tissues after apparently satisfactory treatment of late syphilis. Since that time Collart's work has been confirmed in at least three laboratories in this country, and also in Italy and in England. It was my good fortune to be able to spend several hours with Dr. Collart and his colleagues in his laboratories on the Boulevard Saint-Jacques, in April, 1970. They have been studying an important biological problem with appropriate objectivity, uncovering startling information and not worrying too much about all its implications.

Two points need emphasis here. The first is that even massive and prolonged penicillin treatment of late syphilis sometimes fails to cure it, in the sense that spirochetes persist in the tissues, alive and still virulent for rabbits. This may well be the reason for persistently positive TPI tests in such patients. What it means in terms of actual progress of the disease in these late syphilitics is not yet clear and may not be known for some years. N. S. C. Rice and his English colleagues, who have confined some of Collart's work, make this encouraging comment:

“The findings do not alter the fully substantiated facts that the clinical results of treatment of early syphilis are excellent and that it is only the moist lesions of early syphilis that are infectious by sexual contact.”

The second point is the one that really disturbs me. Dr. Collart showed me some syphilitic rabbits and the fully active spirochetes taken from them, and brought out notebooks with details of his more recent work. He has been able to make these spirochetes resistant to 2.4 million units of penicillin (the common single curative dose for man). Penicillin resistance, a bugbear in gonorrhea, as we will see, has not yet been reported for syphilis outside of Collart's rabbits with a single possible exception. A group of workers at Johns Hopkins University, inheritors of one of the most distinguished traditions of syphilis research, reported in May, 1970, that a baby girl with congenital syphilis died 22 days after birth despite massive penicillin treatment. Penicillin had been given ten days before delivery and for seventeen days after birth. Live and virulent spirochetes were recovered from the infant at autopsy. The case is represented as the first on record in which adequate penicillin treatment failed to halt the progress of early syphilis. That the treatment was adequate by the usual standards became clear when blood samples from both mother and child taken at birth, ten days after the earlier penicillin treatment, showed enough penicillin still in the serum to kill the usual spirochetes. The authors do not speculate on the possible reasons for this baby's death: "Regardless of how T. pallidum survived in this infant, survive it did." They relate their observations to those of Collart and his followers, and mention the possibility of penicillin resistance.