The largest part of the country is tropical savannah with a rainy season from June to October (average rainfall: 1000 mm per year, mean temperature > 25°C), a cold dry season from November to February, (min. temp. 15°C) and a hot dry season from March to May. Malaria transmission is seasonal (June to December)and the major mosquito vectors are A. gambiae, A. funestus and A. arabiensis. Malaria morbidity represents 30 to 50% of febrile illnesses and is the most frequent reason for health centres attendance and hospitals admission.Since it's first notification in 1986, P. falciparum resistance to CQ increased slowly with a considerable variation in space and time and resistance to SP has remained low. CQ clinical failures are in general less than 20% in 6-59 months children and parasitological resistance is around 30%. Malaria prevention in pregnancy is given as weekly 300 mg CQ following a presumptive initial treatment as recommended by the national malaria control programme (MOH). ANC services in health centres provide pregnant women with CQ and haematinics. The health centre 'Centre médical Paul VI' is a peri-urban health facility of Ouagadougou. It comprises general outpatient consultation service, paediatric and maternity wards, and a laboratory.Patients come from the peri-urban districts and the neighbouring villages.