Complement Fixation in Human Malaria Using an Antigen Prepared from the Chicken Parasite Plasmodium Gallinaceum.

The literature concerning various serological reactions in malaria in man has been well reviewed (1). According tothis review, attempts to obtain a specific complement fixation reaction with sera from human beings infected by Plasmodium vivax or by Plasmodium falciparum have led in the past to inconclusive results because no sensitive, specific, and easily standardized antigen was available. Due to the difficulty in obtaining sufficient quantities of heavily infected human blood from which to prepare an antigen, these investigators developed an antigen from Plasmodium knowlesi which occurs naturally in the malaria of monkeys and can be used to induce malaria in man. A complement fixation test using such an antigen was found to give a group reaction with sera from human beings infected with Plasmodium vivax and Plasmodium falciparum. When the onset of war made procurement of monkeys impracticable, two workers (2) prepared an antigen from the chicken malarial parasite Plasmodium gallinaceum. One of them (3) demonstrated the group specificity of this antigen, using the sera of soldiers with malaria at Percy Jones General Hospital. Further studies appeared desirable since there are no certain clinical criteria indicative of a complete cure in malaria and a test that could detect latent malaria would obviously serve a very useful purpose. The present report deals with the serological investigations conducted at the Harmon General Hospital. The antigen prepared from Plasmodium gallinaceum was supplied originally by the aforementioned workers and subsequently by the Army Medical School. The specificity and sensitivity of this complement fixation test was studied