title: Decreased hemoglobin concentrations, hyperparasitemia, and severe malaria are associated with increased Plasmodium falciparum gametocyte carriage.
abstract: To determine factors influencing gametocyte carriage, a cross-sectional study was conducted among 512 patients admitted for Plasmodium falciparum malaria. After adjustments for potential confounders, hemoglobin concentrations were lower in gametocyte carriers 10.5 (+/-2.5) than in patients without gametocytes 12.5 (+/-2.3) (P < 0.0001). Hemoglobin concentrations were negatively correlated with peak gametocyte counts (Spearman's p = -0.37, P < 0.0001) and gametocyte carriage durations (Spearman's p = -(0.30, P < 0.0001). Adjustments for the duration of the malaria episode and other potential confounders did not alter the association (P < 0.0001). After adjustment for potential confounders, the median asexual parasitemia was higher in patients with gametocytes than in patients without gametocytes (P = 0.003). Severe malaria cases were more likely to have gametocytes (65%) than malaria with hyperparasitemia (38%) or mild malaria (31%) (P = 0.0001). These findings suggest that events surrounding anemia and tissue hypoxia stimulate Plasmodium falciparum gametocytogenesis.
authors.affiliation: Unité INSERM 511, Immunobiologie Cellulaire et Moléculaire des Infections Parasitaires, Faculté de médecine Pitié-Salpétrière, Paris, France. m_nacher@lycos.com
authors.forename: Mathieu
authors.initials: M
authors.lastname: Nacher
authors.forename: Pratap
authors.initials: P
authors.lastname: Singhasivanon
authors.forename: Udomsak
authors.initials: U
authors.lastname: Silachamroon
authors.forename: Sombat
authors.initials: S
authors.lastname: Treeprasertsuk
authors.forename: Thanawat
authors.initials: T
authors.lastname: Tosukhowong
authors.forename: Suparp
authors.initials: S
authors.lastname: Vannaphan
authors.forename: Frédérick
authors.initials: F
authors.lastname: Gay
authors.forename: Dominique
authors.initials: D
authors.lastname: Mazier
authors.forename: Sornchai
authors.initials: S
authors.lastname: Looareesuwan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002353:Carrier State / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood / Q000469:parasitology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018512:Parasitemia / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000302:isolation & purification* / Q000502:physiology; D012720:Severity of Illness Index
chemical_list: D006454:Hemoglobins