pfcrt intron 4 microsatellite allelic frequencies in different populations. The relative frequency of the various allelic forms within each haplotype subgroup is indicated. Number of CVMNK/A isolates investigated was 89 from East and Austral Africa and 35 from West and Central Africa. Number of CVIET/S isolates investigated was 37 from East and Austral Africa, 77 from West and Central Africa and 11 from Cambodia. (TAAA)m(TA)n alleles are classified according to the number (n) of TA repeats that follow (TAAA)3 (plain bars) or (TAAA)4 (hatched bars). The colour codes for the various geographical regions are blue for East and Austral Africa, red for West and Central Africa and yellow for Cambodia.