THE PRESENCE OF SICKLE CELLS IN THE PERIPHERAL-BLOOD FILM - SPECIFICITY AND SENSITIVITY OF DIAGNOSIS OF HOMOZYGOUS SICKLE-CELL DISEASE IN KENYA

The final diagnosis of sickle cell disease (SCD) is established by hae moglobin (Hb) electrophoresis. The test, however, is expensive and abs ent in most hospitals in Kenya. We studied sensitivity, specificity an d cost-effectiveness of the peripheral blood film (PBF) in diagnosing sickle cell anaemia (SCA), the most common type of sickle cell disease (SCD) in Kenya, The PBF can be done even in dispensaries. The study w as performed in SCA endemic western Kenya in 767 subjects during 12 mo nths, Hb level, WBC count, PBF, sickle cell test (SCT) and cellulose a cetate paper electrophoresis (CAPE) were performed. In the PBF, presen ce of sickle cells was pathognomonic for SCA, SCA was found in 21, sic kle cell trait in 120, and normal genotype in 616 subjects. Sensitivit y of the PBF versus SCT and CAFE to detect SCA was 76% with a specific ity of 99.7%. The PBF was cheaper than both methods by 31.1%.