Risk factors for gametocyte carriage in uncomplicated falciparum malaria.
The factors affecting the development of patent Plasmodium falciparum gametocytemia were assessed in 5,682 patients entered prospectively into a series of antimalarial drug trials conducted in an area of low and seasonal transmission on the western border of Thailand. Of the 4,565 patients with admission thick smear assessments, 110 (2.4%) had gametocytemia. During the follow-up period 170 (3%) of all patients developed patent gametocytemia, which in 89% had developed by day 14 following treatment. In a multiple logistic regression model five factors were found to be independent risk factors at presentation for the development or persistence of gametocytemia during follow up; patent gametocytemia on admission (adjusted odds ratio [AOR] = 7.8, 95% confidence interval [CI] = 3.7-16, P < 0.001), anemia (hematocrit <30%) (AOR = 3.9, 95% CI = 2.3-6.5, P < 0.001), no coincident P. vivax malaria (AOR = 3.5, 95% CI = 1.04-11.5, P < 0.04), presentation with a recrudescent infection (AOR = 2.3, 95% CI = 1.3-4.1, P < 0.004), and a history of illness longer than two days (AOR = 3.3, 95% CI = 1.7-6.6, P < 0.001). Patients whose infections responded slowly to treatment or recrudesced subsequently were also more likely to carry gametocytes than those who responded rapidly or were cured (relative risks = 1.9, 95% CI = 1.3-2.7 and 2.8, 95% CI = 2.0-4.0, respectively; P < 0.001). These data provide further evidence of important epidemiologic interactions between P. falciparum and P. vivax, and drug resistance and transmission potential.
Shoklo Malaria Research Unit, Mae Sod, Tak Province, Thailand.
R
R
Price
F
F
Nosten
J A
JA
Simpson
C
C
Luxemburger
L
L
Phaipun
F
F
ter Kuile
M
M
van Vugt
T
T
Chongsuphajaisiddhi
N J
NJ
White
D000293:Adolescent; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000009:adverse effects / Q000627:therapeutic use*; D037621:Artemisinins; D002353:Carrier State / Q000188:drug therapy* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D015767:Mefloquine / Q000009:adverse effects / Q000627:therapeutic use; D015999:Multivariate Analysis; D018512:Parasitemia / Q000188:drug therapy* / Q000453:epidemiology; D010616:Phenanthrenes / Q000009:adverse effects / Q000627:therapeutic use; D010963:Plasmodium falciparum / Q000187:drug effects / Q000254:growth & development*; D011446:Prospective Studies; D011803:Quinine / Q000009:adverse effects / Q000627:therapeutic use; D012044:Regression Analysis; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012717:Sesquiterpenes / Q000009:adverse effects / Q000627:therapeutic use; D013785:Thailand / Q000453:epidemiology
D000962:Antimalarials; D037621:Artemisinins; D010616:Phenanthrenes; D012717:Sesquiterpenes; C031327:artemisinin; D011803:Quinine; C023768:halofantrine; D015767:Mefloquine