Serum Vitamin B12Levels and Incidence of Tapeworm Anemia in a Population Heavily Infected with Diphyllobothrium Latum

Abstract

In order to elucidate the incidence of D. latum infection, tapeworm anemia and low serum vitamin B₁₂ levels, a population in Eastern Finland was subjected to a mass examination. Of the 1,345 subjects examined, 27.2 per cent were found to have tapeworm ova in their feces. Among those who had no tapeworm ova 0.3 per cent had a combination of anemia and low serum vitamin B₁₂ level, but none had megaloblastic bone marrow. Among the worm carriers 1.9 per cent had verified (megaloblastic), and another 1.1 per cent suspect (nonmegaloblastic) vitamin B₁₂ deficiency anemia. The incidence of tapeworm anemia in worm carriers is at least 1:50. The mean serum vitamin B₁₂ levels in the tapeworm carrier and control groups were 116.4 and 273.8 µµg./ml., respectively, the difference being statistically highly significant. More than fifty per cent of the worm carriers had a serum vitamin B₁₂ concentration below 100 µµg./ml., whereas this occurred in less than 5 per cent of the control subjects. It is concluded that the incidence of tapeworm anemia is much higher than has hitherto been supposed, that vitamin B₁₂ deficiency is extremely common in D. latum carriers and that the D. latum endemy in Finland is thus to be regarded as a serious public health problem.