Frequent umbilical cord-blood and maternal-blood infections with Plasmodium falciparum, P-malariae, and P-ovale in Kenya

The prevalence of malaria infection in 102 paired maternal-blood and umbili cal cord-blood samples was assessed by microscopy and polymerase chain reac tion (PCR) in a holoendemic area in Kenya. Plasmodium falciparum single-spe cies infection was detected in maternal peripheral blood (3.4%), whereas mi croscopy indicated that no Plasmodium species were in cord blood. In contra st, maternal-blood samples showed a PCR prevalence of 48% for P. falciparum , 25% for P. malariae, and 24% for P. ovale, and cord-blood samples showed a PCR prevalence of 32%, 23%, and 21%, respectively. Although mothers with mixed-species infections were more likely to have offspring infected with m ixed species, the specific malaria species were discordant in paired matern al- and cord-blood samples. Triple-species infections were observed in 11 c ord- and maternal-blood samples at a 5.5-fold greater frequency than expect ed. These findings indicate that Plasmodium species infections in cord bloo d are common, occur at lower densities, and may be acquired before parturit ion.