TABLE 2.

SI for Gambian P. falciparum field isolates showing significant nonrandom erythrocyte invasion

Sample	Parasitemiaa	No. of parasitized erythrocytes containing the indicated no. of parasites:						SIc	Pd
		Observed			Expectedb
		1	2	3+	1	2	3+
JB03	8.1	290	31	1	309	13	0	2.38	<0.01
JB04	11.2	311	29	0	320	19	1	1.47	0.04
JB08	9.3	299	25	5	313	15	0	1.91	<0.01
JB11	3.7	328	14	0	336	6	0	2.20	<0.01
JB17	9.6	304	7	0	296	15	1	0.45e	0.02
JB19	9.1	305	23	1	313	15	0	1.55	0.04
JB20	0.7	306	30	1	318	18	1	1.66	<0.01
JB32	5.2	298	14	2	306	8	0	1.93	0.01
JB48	11.6	356	34	0	366	23	1	1.44	0.03
JB52	5.5	303	15	3	312	9	0	2.00	<0.01
JB56	3.9	302	14	0	310	6	0	2.26	<0.01
JB61	8.1	304	20	3	313	13	0	1.70	0.01
JB62	10.2	329	27	4	341	18	1	1.63	0.01
JB66	9.9	303	23	3	312	16	1	1.54	0.03
JB69	7.2	310	31	4	332	12	0	2.74	<0.01
JB73	17.9	322	44	4	335	33	2	1.36	0.03

^aCalculated by examining at least 1,000 erythrocytes.

^bNumber of parasitized cells expected in each class if invasion were a purely random process (according to a Poisson distribution).

^cCalculated as the observed number of cells with multiple invasions divided by the expected number.

^dAs determined by a chi-square goodness-of-fit test of the observed numbers of erythrocytes with single and multiple invasions (pooled number of erythrocytes with two or more parasites) versus the expected numbers, with the Yates correction.

^eSelectivity was in the opposite direction, showing fewer erythrocytes with multiple invasions than expected.