Comments on “Malaria in China and Equatorial Pacific Area from 1937 to 1943” by Isao Ebisawa

Malaria was the major medical problem confronting the allied military forces in the campaign in the equatorial Pacific area from 1942 through 1945. In the period 1942 through 1943, the disease dominated military strategy. In the Solomon Islands and New Guinea campaigns, American divisions such as the First Marine Division, the Americal Division, the 25th and 43rd Infantry divisions had high proportions of troops at least temporarily incapacitated due to malaria. Plasmodium falciparum infections were a serious problem in the earlier phases. After experience had been gained in the methodology of malaria suppressive regimes, earlier with Atabrine, and toward the end of the war with chloroquine, Plasniodium vivax became the more prominent infection. Plasmodium malariae was only infrequently seen, and Plasmodium ovale was not reported. The impact of malaria was seen most particularly under actual combat conditions, where suppressive regimes might be temporarily forgotten. Plasmodium vivax infections, ordinarily suppressed, broke through the lowered suppressive barrier. Fortunately, the multiple drug-resistant P. falcipar-um strains encountered in the historically recent Vietnam campaigns were either absent or insignificant in the WW II period. When combat units were removed from malarious areas and rested up in rear bases (New Zealand, Australia, Fiji, or British Samoa) controlled studies were made of the effects of discontinuing Atabrine suppression. The results were dramatic. In the 147th Infantry regiment, for example, of 1311 individuals followed for 6 months after discontinuing Atabrine suppression, only 106 did not come down with P. vivax malaria. The situation in the Japanese garrisons in the equatorial Pacific islands can only be surmised. The small number of captives taken were almost invariably malarious. Availability and appropriateness of antimalarial drugs employed by the Japanese, either as therapeutic or suppressive agents was probably curtailed as Japanese supply lines were progressively interrupted. It can only be guessed, but almost certainly correctly, that crippling as malaria was for the Allied forces, it was much more crippling for the Japanese. This in turn must have influenced the malaria experiences of the Allied forces greatly. As Japanese cantonment areas, occupied by malarious Japanese troops were successively invaded and occupied by unseeded Allied forces, these forces certainly encountered anopheline populations heavily loaded with malaria sporozoites, and completely ready to pass the curse of the Japanese garrison on to the newly arrived susceptible invaders. A victorious occupation could be followed in a couple of weeks by devastating malaria. This was certainly seen on Guadacanal,