Longitudinal survey in Northern Senegal to investigate the environmental factors modulating the immune response to childhood vaccines and to malaria.

A cohort of 410 children aged 1 to 10 from 5 villages of the Senegal River Valley(Podor District) was followed-up for 18 months. During that period, 5 visits have been made to the villages to assess the immunological and nutritional status of the children.

Longitudinal survey in Northern Senegal to investigate the environmental factors modulating the immune response to childhood vaccines and to malaria.

A cohort of 410 children aged 1 to 10 from 5 villages of the Senegal River Valley(Podor District) was followed-up for 18 months. During that period, 5 visits have been made to the villages to assess the immunological and nutritional status of the children (T1 (October 2008), T2 (January 2009), T3 (June 2009), T4 (October 2009) and T5 (January 2010)).

The project was approved by the National Ethics Committee of Senegal. Written individual informed consent was obtained from each participant's parent or legal guardian at the beginning of the survey, and at each visit child's and parent's approval was sought orally.

Capillary blood was collected from the finger tip of each child, using sterile single-use material.

Body temperature was measured by means of auricular thermometer at all visits. Anthropomorphic data were collected at visits T2, T3, T4 and T5.

A Hemocue photometer (HemoCue AB, Ängelholm, Sweden) was used to determine haemoglobin concentration on a blood drop at visits T3, T4 and T5.

At each visit, a questionnaire was filled in for every child. Information was collected on the date of birth family membership to asses if siblings or children living in the same house were in the cohort.

Inclusion Criteria:

• Age: between 1 and 10 years

Exclusion Criteria:

• Fever (body temperature superior to 38.5 °C)

Residents of 5 villages from the Senegal Valley River, belonging to the Podor District in Saint-Louis Region in Northern Senegal.

Agniam (16°32'N-14°48'W; total population (TP): 989; several temporary ponds, traditional housing, irrigated crops) Fanaye Diery (16°32'N-15°13'W; TP: 6781; animal husbandry, irrigated crops, some urbanized habitat) Niandane (16°35'N-14°59'W; TP: 5100; Rice and banana farming, irrigated crops, some urbanized habitat) Ndiayène Pendao (16°30'N- 15°03'W; TP: 2734; animal husbandry, Savannah surroundings) Guédé Village (16°33'N-14°48'W; TP:3005; Traditional housing, irrigated crops)