Study of Iron Absorption and Utilization in Asymptomatic Malaria

The Effect of Asymptomatic Malaria on Iron Absorption and Utilization From a Sorghum-based Meal in Adult Women in Benin

Anemia is still a main public health problem in sub-Saharan Africa. Anemic women have an increased maternal and perinatal mortality and anemic adults have diminished work capacity. In sub-Saharan Africa, the etiology of anemia is multifactoral; the major causes are low dietary bioavailability and chronic parasitic infections such as malaria. These causes are likely to interact because infection and infection-associated inflammation may impair the utilization and absorption of iron. Therefore, the control of parasite infections may be important to improve iron bioavailability from foods.

Malaria infections are endemic in northern Benin. To investigate the contribution of asymptomatic malaria (a positive blood smear for malarial parasites but without clinical symptoms of fever, headache or malaise) to anemia, we are planning a human iron absorption study in Benin. We will recruit adults with asymptomatic malaria infection. The iron absorption and utilization of the study subjects will be studied while infected, then they will be treated to clear their infections, and then iron absorption and utilization will be restudied. Iron absorption will be determined by incorporation of labeled iron into erythrocytes, 14 days after the administration of a test meal containing labeled iron (stable isotope technique). Subjects will be men and non-pregnant, non-breastfeeding women with a body weight < 65 kg and between the age of 18 - 30 years.

The results of this study will provide important information on the influence of malaria infections on iron absorption and utilization in humans. The study will provide insight into the potential necessity of malaria control to ensure iron bioavailability from foods in developing countries.

Inclusion Criteria:

• Age 18-35 y
• Body weight < 65 kg
• A positive malaria smear (asexual P. falciparum parasitemia > 500/μL blood) without clinical symptoms (fever or self-reported fever in last 7 days, headache, malaise)
• If female, not pregnant (tested by pregnancy test) and not breastfeeding
• No mineral and vitamin supplements two weeks before and during the study

Exclusion Criteria:

• Severe anemia (hemoglobin < 8.0 g/dl)
• Chronic medical illnesses
• Blood donation or transfusion in the last 6 months before study time
• Soil-transmitted helminth infections (positive Kato-Katz-Smear)
• Tuberculosis (TB): The potential presence of TB will be excluded by a short health questionnaire (cough? night sweats? weight loss? close relative with TB?). If this questionnaire raises the possibility that the subject may be at risk for TB, he/she will be referred to the local medical service