BACKGROUND: Haematological values derived from local populations are useful in laboratories to improve diagnoses for local patients. In Cameroon, these data are not yet available. Moreover, there is great variation in baseline parameters pertaining to full blood cell count among medical laboratories. OBJECTIVES: This study aimed to determine values for the complete blood cell count of a healthy adult Cameroonian population for use in locally derived ranges in our medical laboratories METHODS: A cross-sectional study was conducted among blood donors attending three blood banks in Yaoundé from November 2015 to September 2016. We expected to obtain at least 120 venous blood samples from both men and women. Tests were performed for (1) HIV, (2) complete blood cell count, (3) hepatitis B virus, (4) malaria, (5) syphilis, (6) C-reactive protein and (7) hepatitis C virus. RESULTS: We enrolled 294 healthy participants (161 men, 133 women) aged 18 to 55 years. The median haemoglobin concentration was 135 g/L in men and 114 g/L in women (p < 0.001). The median reticulocyte count was 60 × 10(9)/L in men and 40 × 10(9)/L in women (p < 0.001). Significant variation by sex was observed for the platelet count. The median white blood cell count was 4.1 × 10(9)/L in men and 4.6 × 10(9)/L in women (p = 0.008). CONCLUSION: This study provides locally derived ranges for complete blood cell and reticulocyte counts for a healthy adult population in Yaoundé, Cameroon. These results can be used pending larger studies.

Os limites das ações de comunicação que repousam sobre a informação e a persuasão são conhecidos. Se elas permitem modificar as atitudes e os saberes, elas não permitem, entretanto, modificar os comportamentos efetivos, porque boas atitudes não são suficientes para ter bons comportamentos. O objetivo deste artigo é propor uma nova abordagem de mudança social à luz da teoria do compromisso. Três estudos são relatados, mostrando sua eficácia para promover os comportamentos de cidadania desejados (participação eleitoral, proteção do meio-ambiente e economia de energia). Esta abordagem, chamada "comunicação do compromisso", apóia-se sobre os atos preparatórios e os atos de comprometimento que convém obter das pessoas enfocadas.

We already know the limits of communication actions based on information and persuasion. If that type of actions can lead to changing attitudes and knowledge, they hardly allow modifying the effective behaviours, simply because having the right attitudes is usually not enough to have the right behaviour. The goal of this article is to propose a new approach of social change in the light of the commitment theory. Three studies are reported, which show this theory efficiency to promote required citizenship behaviours: electoral participation, environmental protection and saving energy. This approach, called "committing communication", is based on preparatory acts and acts of commitment which are necessary to obtain from target subjects.