Volume 17, Number 7—July 2011
Research
Co-infections of Plasmodium knowlesi, P. falciparum, and P. vivax among Humans and Anopheles dirus Mosquitoes, Southern Vietnam
Figure 3

Figure 3. Age analysis of persons tested for Plasmodium knowlesi infection, Khanh Phu, Vietnam. A) Age groups of P. knowlesi–positive persons (n = 32; mean age 15.8 y) compared with P. knowlesi–negative persons (n = 179; mean age 26.2 y); p = 0.0004 (significant) by 2-tailed t test with unequal variance. B) Age groups of P. knowlesi–positive persons compared with ages of those positive for other parasites (n = 93; mean age 24.5 y); p = 0.004 (significant) by 2 tailed t test with unequal variance. C) Age groups of P. falciparum–positive persons (n = 95; mean age 23.4 y) compared with P. falciparum–negative persons (n = 116; mean age 25.6 y); p = 036 (not significant) by 2-tailed t test with unequal variance.