Detection of Plasmodium spp. in Human Feces - Vol. 18 No. 4 - April 2012 - Emerging Infectious Disease journal - CDC
Table of Contents
Volume 18, Number 4–April 2012
Volume 18, Number 4—April 2012
Detection of Plasmodium spp. in Human Feces
In spite of a century of research, knowledge of Plasmodium spp. affecting the African great apes is limited. However, molecular tools have recently shown unexpectedly high diversity of these species (1–5). Available evidence supports the scenario in which humans acquired P. falciparum from western gorillas (3,6) and carried it in their blood throughout the world after migrating from Africa (7). However, recent discovery of a P. falciparum–related parasite in the African putty-nosed monkey calls into question this theory of the origin of this most malignant and widespread Plasmodium species (8). All data for identification of Plasmodium spp. were obtained only by PCR-based amplification of feces of free-living great apes (9). Because it is difficult to obtain their blood samples, which are used from for detection of Plasmodium spp. in other hosts, estimation of the prevalence of Plasmodium spp. in great apes is problematic.
AbstractComparison of diagnostic methods for Plasmodium spp. in humans from Uganda and the Central African Republic showed that parasites can be efficiently detected by PCR in fecal samples. These results, which rely solely on PCR-based examination of feces, validate numerous estimates of the prevalence of malaria in great apes.
Plasmodium spp. cause >200 million malaria cases in humans (10). The availability, sensitivity, and accuracy of diagnostic methods often rely on use of blood samples (11), making any attempts to inspect other material from humans for these pathogens unnecessary or impractical. Furthermore, a blood parasite would not be expected to be present in feces at detectable amounts (12). No attempts to identify Plasmodium spp. in feces of infected persons have been reported.
Studies of great apes (3,4,9) have focused on diversity and phylogeny of Plasmodium spp. However, fecal-based diagnostics open a plethora of questions regarding the prevalence, epidemiology, and clinical role of malaria in apes. To answer these questions, we urgently need to assess the reliability of fecal-based diagnostics. Motivated by prior feasibility of such an approach in closely related great apes, we examined whether malarial infection is detectable in feces of infected humans, and if so, in what fraction of infected persons does the parasite penetrate into feces?