[Differential diagnostic value of occult blood in stool in hookworm infection in the Third World. Study from Papua New Guinea].

In 633 persons of the Madang province in Papua-New Guinea hookworm-infection, blood hemoglobin and the presence of blood in stools were studied. 60% of the subjects were infected with hookworm (Necator americanus). There was a significant linear correlation between the intensity of hookworm infection and blood haemoglobin level. The Colo-Rectal test gave positive results in 17% of the cases without worm-infection. In infected persons, the Colo-Rectal test gave an increasing rate of positive results as the parasite infection increased: 24% for subjects with low levels of infection, and 57% and 67% for moderate and high levels, respectively. The mean blood-haemoglobin level was lower in persons with positive Colo-Rectal-Test and hookworm infection (11.8 g%) than among those with negative Colo-Rectal-Test and hookworm infection (15.0 g%, p < 0.01). In young populations with a known high prevalence of hookworm infection, Colo-Rectal test is therefore suitable for the detection of moderate or severe hookworm infections. It may serve as a simple and useful method to work up anaemia is such populations.