You can find an article on the epidemiology of CF in South Africa at http://www.sajch.org.za/index.php/SAJCH/article/view/48 . The epidemiology of CF among black Africans is not at all clear. More and more cases are being identified (e.g. http://samj.org.za/index.php/samj/article/viewFile/1092/547 ) but not nearly as many as predicted in the only study to look at CFTR mutations in black populations in Africa – http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1762947/ . Is the study wrong in its predictions or is the phenotype of CF different? Very few black CF patients are being seen with meconium ileus, for example. In other populations about 15% of cases have MI.

The most comprehensive view of the CFTR mutations found in the CF patients in South Africa was published from Johannesburg by Goldman and colleagues: http://www2.samj.org.za/index.php/samj/article/viewFile/2255/1522