Portal de Periódicos da CAPES

AGE-DEPENDENT DISTRIBUTION OF PLASMODIUM FALCIPARUM GAMETOCYTES QUANTIFIED BY PFS25 REAL-TIME QT-NASBA IN A CROSS-SECTIONAL STUDY IN BURKINA FASO

2007; American Society of Tropical Medicine and Hygiene; Volume: 76; Issue: 4 Linguagem: Inglês

10.4269/ajtmh.2007.76.626

1476-1645

ANDRÉ LIN OUÉDRAOGO, Petra Schneider, M. de Kruijf, Issa Nébié, J. P. Verhave, N. Cuzin‐Ouattara, R. W. Sauerwein,

Vector-borne infectious diseases

Sexual stages of Plasmodium falciparum play a key role in the transmission of malaria. Studies on gametocytes are generally based on microscopic detection, but more sensitive detection methods for P. falciparum gametocytes frequently detect sub-patent gametocytes. We used Pfs25 mRNA quantitative-nucleic acid sequence-based amplification (QT-NASBA) to quantify gametocytes in 412 samples from a cross-sectional study in Burkina Faso, covering all age groups, to determine age-related patterns in gametocyte carriage and gametocyte density. The more sensitive QT-NASBA technique gave estimates of gametocyte prevalence 3.3-fold higher than microscopy (70.1% versus 21.4%, respectively). Prevalence of gametocytes significantly decreased with age. Our data suggest that asexual parasite densities are primarily responsible for the age-related decrease of gametocyte prevalence, possibly because of developing asexual stage immunity. Gametocyte densities decrease also with age, primarily because of decreasing asexual parasite densities; only a small but significant age effect on gametocyte density may be caused by developing sexual stage-specific immunity.