Epidemiology of Orofacial clefts in Africa: Methodological challenges in ascertainment

BACKGROUND To carry out a systematic review of the birth prevalence of cleft lip with or without cleft palate (CLP) and cleft palate (CP) in Africa based on available published data. METHOD Using the Cochrane search strategy and the following keywords words "cleft palate", "prevalence", "incidence", "cleft lip" and "Africa" to screen Ovid Medline {1966 to March 2007), Cinahl {1982-March 2007}, Pub Med, Scopus, and Web-Google. All identified published, prospective and retrospective studies on the birth prevalence of CLP and CP in Africa were included. The dates, location, sources, number of births (live births, still births, number of cleft cases, prevalence rates, sex ratio, cleft types, and clefts with associated anomalies were extracted. RESULTS Ascertainment of cases was through the hospitals. Overall there were 57 CL/P, 56 CL and 36 CP reported from all the studies. From seven studies combined, 21 males and 20 females had CL, 10 males and 22 females with CP and 26 males and 24 females with CL/P. There were 3 cases with CL/P, 2 with CP and 2 with CL from the three studies that reported clefts with associated anomalies. CONCLUSION For an improved ascertainment of cleft cases, there is a need to set up a birth defects surveillance system in the form of a national birth registry. Future studies should then aim to include the entire population in geographically defined regions. Reliable data on incidence is an essential pre-requisite for studies into aetiology and prevention.