Chapter VI The Blood Test for Syphilis

It seems desirable at this point, while we are trying to fix in mind the great value of recognizing syphilis in a person in order to treat it and thus prevent dangerous complications, to say something about the blood test for syphilis, the second great advance in our means of recognizing doubtful or hidden forms of the disease. The first, it will be recalled, is the identification of the germ in the secretions¹ from the early sores.

Antibodies in the Blood in Disease.—It is part of the new understanding we have of many diseases that we are able to recognize them by finding in the blood of the sick person substances which the body makes to neutralize³ or destroy the poisons made by the invading germs, even when we cannot find the germs themselves. These substances are called antibodies, and the search for antibodies in different diseases has been an enthusiastic one. If we can by any scheme teach the body to make antibodies for a germ, we can teach it to cure for itself the disease caused by that germ. So, for example, by injecting dead germs as a vaccine⁴ in typhoid fever and certain other diseases, we are able to teach the body to form protective substances which will kill any of the[Pg 55] living germs of that particular kind which gain entrance to the body. Conversely, if the body is invaded by a particular kind of germ, and we are in doubt as to just which one it is, we can identify it by finding in the blood of the sick person the antibody which we know by certain tests will kill or injure a certain germ. This sort of medical detective work was first applied⁵ to syphilis successfully by Wassermann, Neisser, and Bruck in 1904, and for that reason the test for these antibodies in the blood in syphilis is called the Wassermann reaction. To be sure, it is now known that in syphilis it is not a true antibody for the poisons of the Spiroch?ta pallida for which we are testing, but rather a physical-chemical change in the serum⁶ of patients with syphilis, which can be produced by other things besides this one disease. But this fact has not impaired⁷ the practical value of the test, since the other conditions which give it are not likely to be confused with syphilis in this part of the world. The fact that no true antibody is formed simply makes it unlikely that we shall ever have a vaccine for syphilis.

Difficulties of the Test.—The Wassermann blood test for syphilis is one of the most complex tests in medicine. The theory of it is beyond the average man's comprehension. A large number of factors enter into the production of a correct result, and the attaining⁸ of that result involves a high degree of technical skill and a large experience. It is no affair for the amateur. The test should be made by a specialist of recognized standing², and this term does not include many of the commercial laboratories[Pg 56] which spring up like mushrooms in these days of laboratory methods.

The Recognition of Syphilis by the Blood Test.—When the Wassermann test shows the presence of syphilis, we speak of it as "positive." Granted that the test is properly done, a strong positive reaction means syphilis, unless it is covered by the limited list of exceptions. After the first few weeks of the disease, and through the early secondary period, the blood test is positive in practically all cases. Its reliability¹⁰ is, therefore, greatest at this time. Before the infection has spread beyond the first sore, however, the Wassermann test is negative, and this fact makes it of little value in recognizing early primary lesions. In about 20 to 30 per cent of syphilitic individuals the test returns to negative after the active secondary stage is passed. This does not necessarily mean that the person is recovering. It is even possible to have the roof fall out of the mouth from gummatous changes and the Wassermann test yet be negative. It is equally possible, though unusual, for a negative Wassermann test to be coincident with contagious¹¹ sores in the mouth or on the genitals. So it is apparent that as an infallible test for syphilis it is not an unqualified success. But infallibility is a rare thing in medicine, and must be replaced in most cases by skilful¹² interpretation¹³ of a test based on a knowledge of the sources of error. We understand pretty clearly now that the Wassermann test is only one of the signs of syphilis and that it has quite well-understood limitations. It has revealed an immense[Pg 57] amount of hidden syphilis, and in its proper field has had a value past all counting. Experience has shown, however, that it should be checked up by a medical examination to give it its greatest value. Just as all syphilis does not show a positive blood test, so a single negative test is not sufficient to establish the absence of syphilis without a medical examination. In a syphilitic, least of all, is a single negative Wassermann test proof that his syphilis has left him. In spite of these rather important exceptions, the Wassermann test, skilfully¹⁴ done and well interpreted, is one of the most valuable of modern medical discoveries.

The Blood Test in the Treatment and Cure of Syphilis.—In addition to its value in recognizing the disease, the Wassermann test has a second field of usefulness in determining when a person is cured of syphilis, and is an excellent guide to the effect of treatment. Good treatment early in a case of syphilis usually makes the Wassermann test negative in a comparatively short time, and even a little treatment will do it in some cases. But will it stay negative if treatment is then stopped? In the high percentage of cases it will not. It will become positive again after a variable interval¹⁵, showing that the disease has been suppressed but not destroyed. For that reason, if we wish to be sure of cure, we must continue treatment until the blood test has become negative and stays negative. This usually means repeated tests, over a period of several years, in connection with such a course of treatment as will be described later. During a large part of this time[Pg 58] the blood test will be the only means of finding out how the disease is being affected¹⁶ by the treatment. To all outward appearance the patient will be well. He may even have been negative in repeated tests, and yet we know by experience that if treatment is stopped too soon, he will become positive again. There is no set rule for the number of negative tests necessary to indicate a cure. The whole thing is a matter of judgment¹⁷ on the part of an experienced physician, and to that judgment the patient should commit himself unhesitatingly. If a patient could once have displayed before him in visible form the immense amount of knowledge, experience, and labor⁹ which has gone into the devising and goes into the performing of this test, he would be more content to leave the decision of such questions to his physician than he sometimes is, and would be more alive to its reality and importance. The average man thinks it a rather shadowy and indefinite affair on which to insist that he shall keep on doctoring, especially after the test has been negative once or twice.

Just as a negative test may occur while syphilis is still actively¹⁸ present and doing damage in the body, so a positive Wassermann test may persist long after all outward and even inward signs of the disease have disappeared. These fixed¹⁹ positives are still a puzzle to physicians. But many patients with fixed positives, if well treated regardless of their blood test, do not seem to develop the late accidents of the disease. If their nervous systems, on careful examination, are found not to be affected, they are[Pg 59] reasonably safe as far as our present knowledge goes. People with fixed positives should accept the judgment of their physicians and follow their recommendations for treatment without worrying themselves gray over complications which may never develop.

Practical Points About the Test.—Certain practical details about this test are of interest to every one. Blood for it is usually drawn²⁰ from a small vein²¹ in the arm. The discomfort²² is insignificant—no more than that of a sharp pin-prick. Blood is drawn in the same way for other kinds of blood tests, so that a needle-prick in the arm is not necessarily for a Wassermann test. There is no cutting and no scar remains²³. The amount of blood drawn is small and does not weaken one in the least. The test is done on the serum or fluid part of the blood, after the corpuscles are removed. It can also be done on the clear fluid taken from around the spinal²⁴ cord, and this is necessary in certain syphilitic nervous diseases. There is nothing about the test that need make anybody hesitate in taking it, and it is safe to say that, when properly done, the information that it gives is more than worth the trouble, especially to those who have at any time been exposed, even remotely, to the risk of infection. But the test must be well done, by a large hospital or through a competent physician or specialist, and the results interpreted to the patient by the physician and not by the laboratory that does the test, or in the light of the patient's own half-knowledge of the matter.

1 secretions   

n.分泌（物）( secretion的名词复数 )

参考例句：

• Lysozyme is an enzyme found in egg white, tears, and other secretions. 溶菌酶是存在于卵白、泪和其他分泌物中的一种酶。 来自辞典例句
• Chest percussion and vibration are used with postural drainage to help dislodge secretions. 在做体位引流时要敲击和振动胸部帮助分泌物松动排出。 来自辞典例句

2 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

3 neutralize   

v.使失效、抵消，使中和

参考例句：

• Nothing could neutralize its good effects.没有什么能抵消它所产生的好影响。
• Acids neutralize alkalis and vice versa.酸能使碱中和碱，亦能使酸中和。

4 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

5 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

6 serum   

n.浆液，血清，乳浆

参考例句：

• The serum is available to the general public.一般公众均可获得血清。
• Untreated serum contains a set of 11 proteins called complement.未经处理的血清含有一组蛋白质，共11种，称为补体。

7 impaired   

adj.受损的；出毛病的；有（身体或智力）缺陷的v.损害，削弱( impair的过去式和过去分词 )

参考例句：

• Much reading has impaired his vision. 大量读书损害了他的视力。 来自《现代汉英综合大词典》
• His hearing is somewhat impaired. 他的听觉已受到一定程度的损害。 来自《现代汉英综合大词典》

8 attaining   

（通常经过努力）实现( attain的现在分词 )； 达到； 获得； 达到（某年龄、水平、状况）

参考例句：

• Jim is halfway to attaining his pilot's licence. 吉姆就快要拿到飞行员执照了。
• By that time she was attaining to fifty. 那时她已快到五十岁了。

9 labor   

n.劳动，努力，工作，劳工；分娩；vi.劳动，努力，苦干；vt.详细分析；麻烦

参考例句：

• We are never late in satisfying him for his labor.我们从不延误付给他劳动报酬。
• He was completely spent after two weeks of hard labor.艰苦劳动两周后，他已经疲惫不堪了。

10 reliability   

n.可靠性，确实性

参考例句：

• We mustn't presume too much upon the reliability of such sources.我们不应过分指望这类消息来源的可靠性。
• I can assure you of the reliability of the information.我向你保证这消息可靠。

11 contagious   

adj.传染性的，有感染力的

参考例句：

• It's a highly contagious infection.这种病极易传染。
• He's got a contagious laugh.他的笑富有感染力。

12 skilful   

(=skillful)adj.灵巧的，熟练的

参考例句：

• The more you practise,the more skilful you'll become.练习的次数越多，熟练的程度越高。
• He's not very skilful with his chopsticks.他用筷子不大熟练。

13 interpretation   

n.解释，说明，描述；艺术处理

参考例句：

• His statement admits of one interpretation only.他的话只有一种解释。
• Analysis and interpretation is a very personal thing.分析与说明是个很主观的事情。

14 skilfully   

adv. (美skillfully)熟练地

参考例句：

• Hall skilfully weaves the historical research into a gripping narrative. 霍尔巧妙地把历史研究揉进了扣人心弦的故事叙述。
• Enthusiasm alone won't do. You've got to work skilfully. 不能光靠傻劲儿，得找窍门。

15 interval   

n.间隔，间距；幕间休息，中场休息

参考例句：

• The interval between the two trees measures 40 feet.这两棵树的间隔是40英尺。
• There was a long interval before he anwsered the telephone.隔了好久他才回了电话。

16 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

17 judgment   

n.审判；判断力，识别力，看法，意见

参考例句：

• The chairman flatters himself on his judgment of people.主席自认为他审视人比别人高明。
• He's a man of excellent judgment.他眼力过人。

18 actively   

adv.积极地，勤奋地

参考例句：

• During this period all the students were actively participating.在这节课中所有的学生都积极参加。
• We are actively intervening to settle a quarrel.我们正在积极调解争执。

19 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

20 drawn   

v.拖，拉，拔出；adj.憔悴的，紧张的

参考例句：

• All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
• Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。

21 vein   

n.血管，静脉；叶脉，纹理；情绪；vt.使成脉络

参考例句：

• The girl is not in the vein for singing today.那女孩今天没有心情唱歌。
• The doctor injects glucose into the patient's vein.医生把葡萄糖注射入病人的静脉。

22 discomfort   

n.不舒服，不安，难过，困难，不方便

参考例句：

• One has to bear a little discomfort while travelling.旅行中总要忍受一点不便。
• She turned red with discomfort when the teacher spoke.老师讲话时她不好意思地红着脸。

23 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

24 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。