Table 1.

Mixed infections detected by RT-qPCR and parasite density determined by microscopic examination of TBS detecting Plasmodium malariae, P. vivax, and P. falciparum as species infective in individuals living in Pará state, Amazon region, Brazil

Plasmodium species	Number of positive samples using molecular assay and optical microscopy		Parasite density (Parasites per microliter of blood in TBS)
	RT-qPCR n (%) [95% CI]	TBS n (%) [95% CI]	Mean ± SD (Range)
P. vivax (Pv)	26 (20.7) [13.6–27.7]	48 (51.6) [41.5–61.8]	8,829 ± 16,184 (10–63,500)
P. falciparum (Pf)	42 (33.3) [25.1–41.6]	44 (47.3) [37.2–57.5]	9,102 ± 10,779 (20–37,250)
P. vivax and P. falciparum*	12 (9.5) [4.4–14.6]	1 (1.1)	na†
P. malariae (Pm)	0	0	0
P. vivax and P. malariae	42 (33.3) [25.1–41.6]	0	0
Three species (Pm, Pv, and Pf)	4 (3.2) na†	0	0
Total	126	93	na

A total of 126 samples were analyzed by RT-qPCR, of these 93 were positive in TBS and the number of parasites was calculated per microliter of blood; other 33 was expressed as positive using cross without count of parasites. RT-qPCR = real-time quantitative PCR; SD=: standard deviation; TBS = thick blood smear.

^*One sample was double positive for Pv (15,500 parasites) and Pf (18 gametocytes) per microliter of blood.

^†na = not applicable.