The routine treatment of children with antimalarials will be monitored. Children with a positive malaria film and/or a positive rapid diagnostic test (RDT) will be included in a follow-up study. The genetic basis of the parasites for developing resistance will be examined. In case of reappearance of parasites the child will be re-treated following the guidelines of the national malaria programme.

Children from the Bandim area in Bissau who are seeking medical advice and who are recommended treatment for malaria in accordance with the current routines will be included as follows:

All children getting the clinical diagnosis of malaria will be registered and basic information collected. Of theses, children fulfilling the inclusion criteria will be included in a follow-up study.

The children included in the follow-up part of the study will be visited on day 7, day 14, day 21, day 28, day 35 and day 42. At each visit the condition of the child will be evaluated, a questionnaire will be filled in and a malaria film and approximately 100 µl blood on filter-paper (for PCR analysis in case of re-parasitaemia) will be taken. Furthermore, on day seven 100 μl blood on filter-paper will be taken for drug-analysis.

Children with parasitaemia detected by only one of the following methods will be excluded from the final analyses of the effectiveness: 1) malaria film, 2) RDT, and 3) PCR.

If the parents do not ensure that the children get the correct medication resulting in a high rate of recrudescence and/or a low drug-concentration on day seven the policy of the National Malaria Programme should be re-evaluated. If the health staff do not follow the guidelines of the National Malaria Programme the reasons why should be elucidated in order to ensure a better adherence.

Inclusion Criteria:

• Prescribed an anti-malarial at the Bandim Health Centre
• Having P. falciparum parasites in a thick film and/or a positive RDT
• The Bandim address is known (to enable follow up).

Exclusion Criteria:

• Children where the parents do not accept to participate in the study.
• Signs of severe malaria such as convulsion or severe anemia

Children diagnosed as having malaria at Bandim Health Center in Bissau. Of these all children with a positive malaria film and/or a positive rapid diagnostic test will be included in an observational follow-up study.