Unexpected selections of Plasmodium falciparum polymorphisms in previously treatment-naïve areas after monthly presumptive administration of three different anti-malarial drugs in Liberia 1976–78

Table 1 Pfnhe-1 ms4760 types

ms4760 haplotype	Chlorproguanil	Pyrimethamine	Chloroquine	Vitamin B	Total
Number of previously described ms4760 haplotypes with no variation in block I^a	22	25	25	17	89
Number of novel ms4760 haplotypes with no variation in block I^b	4	2	13 ^d	6	25
Number of novel ms4760 haplotypes with variation in block I^c	9	17	0 ^e	16	42
Total no. of different haplotypes	13	29	10	23	55
Total no. of samples	35	44	38	39	156

Resistance associated alleles are shown in italics
^aPreviously described ms4760-1, -3, -4, -5, -7, -28, -98 and Mali_15 with no variation in block I
^bms4760 haplotypes Lib_01 to Lib_15 with no variation in block I
^cms4760 haplotypes Lib_19 to Lib_47 with variation in block I
^dThe frequency of samples with no variation in block I was higher in the CQ treated village compared with the frequencies in the villages treated with CPGN (P = 0.028), PYR (P = 0.001), placebo (P = 0.068) and with pooled data from all villages (P = 0.001)
^eThe frequency of samples with variation in block I was lower in the CQ treated village when compared with separate and pooled frequencies from the other villages (P < 0.001)

ISSN: 1475-2875