The virulent spirochete tests would probably replace all others if they were easier to do, and they would be easier, for example, if virulent spirochetes could be cultured. But they still have a few drawbacks, and it is possible that reagin type tests would continue to be needed in any event.

A simpler test was worked out at the Venereal Disease Research Laboratories of the U.S. Public Health Service at the Center for Disease Control in Atlanta, and is known by the initials of the laboratories, the VDRL test. It is the one most widely used now for premarital screening, preliminary tests, and tests done routinely for private physicians; and it has been coming into use all over the world.

We measure the reliability of these tests in terms of two qualities, which we call sensitivity and specificity. The words are clear enough if you will think about them. A sensitive test picks up more cases of syphilis, misses fewer cases, does not turn up as many false negatives.

The first group, still the most widely used, is based on the test discovered by Wassennann and his team in 1906, and his name is still given to the particular form of the test he discovered. These tests, surprisingly enough, all depend on an antibody which has no direct connection with the spirochete of syphilis.

In the chancre stage of syphilis, diagnosis depends on identifying spirochetes in the sore, or sometimes in the regional lymph nodes. The best way to do this is with a darkfield microscope, which means having the patient and the microscope not more than a few feet apart, so that fresh fluid can be put on a slide and examined before it dries.

The venereal diseases are all caused by single microbes and ought therefore to be as near simplicity as we can get. Moreover, they are all bacterial diseases and therefore unlike virus diseases treatable with antibiotics. There are nevertheless some technical difficulties.

The first step is to be sure we know certain things about infectious disease, a subject on which misconceptions have been increasing since the new drugs encouraged the idea that the whole problem would soon be cleared up. Most people know that virus diseases like colds, influenza, and hepatitis have not been taken care of yet.

The public health people don't need to tell them they are not succeeding very well. They are not giving up, but they show signs of discouragement. Partly for this reason they are trying to get at the problem in other ways. One is to try to devise new techniques, or to perfect old ones, so that doctors who are busy with other (more important?) things will have less excuse for not bothering.

He who knows syphilis, knows medicine," said the great physician Sir William Osler; and the famous remark heads Chapter 1 of a little book called Syphilis: a Synopsis written for doctors by the U.S. Public Health Service and dated 1968. Somewhere the book admits that "many physicians have been graduated without an adequate knowledge of the many faces of syphilis" -- which was possibly the polite understatement of 1968.

Two seventeenth century drawings included in the treatise by W. A. Pusey show the treatment of syphilis. In one, several patients and attendants appear in various positions. A patient is covered except for his head in an enclosure or cabinet, with a towel hanging from his head.