Parasitology Division, Center for Disease Control, Public Health Service, U.S. Department of Health, Education, and Welfare, Department of Serology, Walter Reed Army Institute of Research, Walter Reed Army Medical Center, Atlanta, Georgia 30333
The complement fixation (CF), indirect immunofluorescence (IIF), and indirect hemagglutination (IHA) tests for malaria were compared by using sera from U.S. citizens with either natural infections or heroin-associated, needle-induced infectons. In natural Plasmodium vivax infections, the CF, IIF, and IHA tests apparently detect malarial antibodies equally efficiently for the first 2 months after the onset of symptoms, but the titers obtained by CF and IIF rapidly decline within a year, while the IHA titers remain elevated. In the sera from heroin addicts who developed needle-induced P. vivax infections, sensitivities of all three tests were decreased: the IIF and IHA tests each detected 83%, but the CF test detected only 57.1%. False-positive reactions with this group were very high for the CF (76.6%) and IHA (15.9%) tests, but only 2% for IIF.