The lower Hb levels in women are a common phenomenon in several other African studies [10]–[12], [15]–[19] these levels can further be exacerbated by poor nutritional status resulting in iron deficiency, genetic disorders including thalassemia and sickle cell trait or infections with helminthes, malaria or schistosomiasis for which we did not test. Here, GSTM1 is linked to schistosomiasis.