Prevalence of hookworm infection, anaemia and faecal blood loss among the Yupno people of Papua New Guinea.

The present report describes a study of hookworm infection, anaemia and the presence of blood in stool among the inhabitants of the Yupno area in Madang Province, Papua New Guinea. The study group comprised 588 persons of all age groups. A second group of 45 patients attending the Madang General Hospital, in the provincial capital on the coast, was used for comparison. In the Yupno area, 59% of the subjects were infected with hookworm; in the coastal group the infection rate was 82%, which was significantly higher. There is therefore a moderate prevalence of hookworm infection in the Yupno area, which does not impair the health of the population to any great extent. In both places there was a clear increase in the infection rate between the group of children 1-5 years old and the older groups. The mean blood haemoglobin level was 15.1 g/dl among the Yupno, which was significantly higher than that of the second group (10.7 g/dl). There was a significant negative linear correlation between the intensity of hookworm infection and blood haemoglobin level. The Colo-Rectal-Test for blood in stool was used on samples from 145 persons in the Yupno and from 43 in the coastal group. The 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 burden increased: 24% for subjects with low levels of infection, and 57% and 67% for moderate and high levels, respectively. The Colo-Rectal-Test is therefore a simple method for the detection of faecal blood loss in populations with a high prevalence of hookworm infection. However, it is not useful as an instrument for general screening for hookworm infections.