Scott and others1 report that their results with B6 mice and Plasmodium yoelii 17X “suggest that chronic tuberculosis worsens in the presence of an acute malarial infection.” Several old studies with Macaca mulatta on the reciprocal interaction may be of interest here. First, Coggeshall and Kumm2 made the intriguing claim that, “It has been repeatedly observed that tuberculosis has an inhibitory effect on the course of P. knowlesi infection in monkeys,” although their own results seemed to involve just one unexpected, concurrently-infected survivor. Singh and others3 found peak and mean P. knowlesi parasitemia were dramatically decreased by concurrent tuberculosis, but all 15 experimental and 10 control animals died quickly; with P. inui, three concurrently infected animals died within days versus months in five controls. Bazaz-Malik4 reported increased survivorship, with these two species and P. cynomolgi. Finally, in this journal, Freund and others5 summarized the results of their famous malaria-vaccine adjuvant studies: “Killed P. knowlesi parasites emulsified in paraffin oil containing killed tubercle bacilli protect rhesus monkeys against fatal infection with P. knowlesi. … No satisfactory substitutes were found for killed tubercle bacilli.”
Scott CP, Kumar N, Bishai WR, Manabe YC, 2004. Short report: modification of Mycobacterium tuberculosis infection by Plasmodium in the murine model. Am J Trop Med Hyg 70 :144–148.
Coggeshall LT, Kumm HW, 1938. Effect of repeated superinfection upon the potency of immune serum of monkeys harboring chronic infections of Plasmodium knowlesi. J Exp Med 68 :17–27.
Singh JP, Ray AP, Nair CP, 1956. Relationship of tuberculosis on the course and intensity of plasmodial infections in M. mulatta.Indian J Malariol 10 :3–10.
Bazaz-Malik G, 1973. Increased resistance to malaria after Mycobacterium tuberculosis infection. Indian J Med Res 61 :1014–1024.
Freund J, Thomson KJ, Sommer HE, Walter AW, Pisani TM, 1948. Immunization of monkeys against malaria by means of killed parasites with adjuvants. Am J Trop Med 28 :1–22.