Differences in blood status of three ethnic groups inhabiting the same locality in Northern Nigeria. Anaemia, splenomegaly and associated causes.

In a village population in N. Nigeria the Fulani form a heterogeneous group in comparison with the Hausa and Maguzawa people. It was demonstrated that, apart from having a different body build, Fulani men have on the average lower haemoglobin concentrations, more splenomegaly and higher IgM and IgG concentrations. Splenomegaly and higher IgM levels were correlated in the Fulani only, and this probably is a manifestation of their altered immune response to malaria, which is manifested by the prolonged parasitaemia in Fulani men suggesting that their control over malaria parasites is less effective. Very high IgM levels (more than 9.6 g/l) were present in 6/70 (9%) of Fulani and in none of the others. According to the criteria used the Tropical Splenomegaly Syndrome could be diagnosed in 4/70 (6%) of Fulani and in 2/89 (2%) of Hausa and Maguzawa. A nutritional factor, presumably iron intake, and Schistoma haematobium infections appeared to be determinants of haemoglobin concentration in the Hausa and Maguzawa. In Fulani a different pattern emerged characterised by the nutritional factor and a haemolytic factor related to the sickle cell trait. The frequency of the sickle cell trait, however, was similar in all tribes. The significance of the findings is discussed and it is suggested that the heterogeneity of Fulani is possibly due to their less complete adaptation to stable malaria.