. 2016 Dec 12;10(12):e0005221. doi: 10.1371/journal.pntd.0005221

Table 2. Absolute and relative frequency of symptomatic and asymptomatic Plasmodium vivax infections diagnosed by quantitative real-time polymerase chain reaction (qPCR) among members of index, neighbor, and control households (HHs) in four rounds of reactive case detection (RCD) in Acrelândia, Brazil, 2013.

RCD round	Type of infection	Index HHs		Neighbor HHs		Control HHs		P-value^a
RCD round	Type of infection	Number of infections	%	Number of infections	%	Number of infections	%	P-value^a
1 (Day 0)	Symptomatic	6	4.1%	6	0.9%	2	0.3%	0.001
	Asymptomatic	16	10.9%	31	4.6%	33	5.2%	0.009
	Total^b	22	15.0%	37	5.5%	35	5.5%	<0.001
	No. tested	147		674		631
2 (Day 30)	Symptomatic	8	5.6%	9	1.4%	2	0.3%	<0.001
	Asymptomatic	10	7.0%	36	5.6%	33	5.3%	0.721
	Total^b	18	12.6%	45	7.0%	35	5.6%	0.012
	No. tested	143		645		626
3 (Day 60)	Symptomatic	4	2.9%	16	2.4%	0	0.0%	<0.001
	Asymptomatic	7	5.0%	19	2.9%	2	0.3%	<0.001
	Total^c	11	7.9%	35	5.3%	2	0.3%	<0.001
	No. tested	139		660		634
4 (Day 180)	Symptomatic	4	2.7%	13	1.9%	2	0.3%	0.007
	Asymptomatic	6	4.1%	21	3.1%	7	1.0%	0.012
	Total^c	10	6.8%	34	5.0%	9	1.3%	< 0.001
	No. tested	146		686		676

^aTwo-tailed P-values for χ² tests on 3 × 2 contingency tables testing the null hypothesis of similar proportions of positive results across rows.

^bPairwise comparisons of positivity rates across row with Fisher exact test (at 5% significance): index HHs > neighbor and control HHs; neighbor HHs = control HHs.

^cPairwise comparisons of positivity rates across row with Fisher exact test (at 5% significance): index and neighbor HHs > control HHs; index HHs = neighbor HHs.