Wassermann Test Background
The Wassermann Test, named after German physician and bacteriologist August von Wassermann, was developed in 1906. The exam involves testing patients’ blood samples for the syphilis bacterium antibody. Syphilis, an STD, is treatable in early stages through doses of penicillin. However, at the third stage of the disease, the bacteria travels and infects both the brain and heart, leading to blindness, insanity, and sterility. Though the Wassermann Test is the most effective way in identifying a syphilis infection, there is still a relatively high rate of false negative test results. Therefore, multiple, continuous tests to ensure a lack of the syphilis bacteria may be necessary.
Wassermann Test Process
The Wassermann Test is reliant upon the Wassermann reaction, which simply indicates the process of a body producing substances to protect against foreign objects inside: in this case, the syphilis bacteria. The Wassermann Test thus includes two components:
Syphilitic system: If a patient’s body has been fighting against syphilis antigens, it would create and release amboceptors. If the amboceptors are found, then the disease is also present. In order to identify the amboceptors, blood serum is extracted from a large superficial vein in the arm. The serum should then be heated so that it is killed. A complement will then be added from another animal to the blood serum. This will prepare the serum for identification of amboceptors.
Hemolytic system: Hemolytic antigens are typically consist of sheep’s red blood cells that are washed through the blood system of a rabbit. The serum is then heated to kill the complements of the rabbit, leaving the amboceptors of the sheep.
The syphilitic system and hemolytic system are mixed together, and two observations are made: one soon after and one after being iced overnight.
Diagnosing During Different Stages of Syphilis
If there is complete non-hemolysis of the sheep’s red blood cells, meaning that the sheep’s red blood cells appear the same as before being mixed, it means that the patient’s serum contained the syphilis amboceptors, and is a “++++” on the Wassermann test. A positive Wassermann test ranges from “++++,” meaning a strong positive, to a “+/-,” meaning a weak positive, depending on the level of non-hemolysis of the sheep’s red blood cells. Complete hemolysis indicates a negative test result.
Primary syphilis: The Wassermann Test has difficulty identifying primary syphilis due to the fact that tissue destruction to a degree where sufficient reagin is produced has not occurred. The primary stage of syphilis is the optimal point of diagnosis to begin treatment. Therefore, research to determine a more effective method of diagnosing syphilis is still being conducted.
Secondary syphilis: The Wassermann reaction will nearly always be positive if tested during secondary syphilis. This is because of the active proliferation and widespread dissemination of infecting organisms, which leads to an abundance of reagin formed. 90-95% of syphilis cases tested through the Wassermann reaction will return positive, and secondary syphilis is the most reliable time to use the Wassermann reaction to diagnose.
Latent syphilis: Late syphilis (tertiary syphilis) and neurosyphilis often presents with minimal external symptoms. Due to the absence of clinical symptoms during this time,, the Wassermann Test is most diagnostically valuable. Again, the Wassermann test has relatively high probability for error, and therefore many tests should be conducted among different laboratory settings in order to eliminate technical error. A cerebro-spinal fluid exam should also be conducted.
Author - Sara Stevens