[Longitudinal surveillance of sensitivity of Plasmodium falciparum to pyronaridine in south Yunnan].
OBJECTIVE
To understand the changes in the sensitivity of Plasmodium falciparum to pyronaridine in the south of Yunnan Province.


METHODS
WHO standard in vivo and in vitro microtest was used.


RESULTS
In 1984-1985 and 1995, 36 and 39 cases of acute falciparum malaria were observed, the average defervescence time being 32.7 +/- 16.0 h and 56.2 +/- 27.4 h, the mean asexual parasite clearance time, 64.2 +/- 22.9 h and 55.3 +/- 11.8 h, and the recrudescence rate of patients followed up for 28 days, 15.2%(5/33) and 37.5%(9/24), respectively. The resistance rates of resistant isolates by in vitro microtest were 0(0/24), 8.8%(3/34), 13.8%(4/29) and 36.4%(4/11) in 1988, 1990, 1992 and 1995, respectively, while the corresponding ID50 were 13.0, 20.0, 32.0 and 40.0 nmol/L, ID95 were 48.0, 136.0, 325.0 and 330.0 nmol/L, the mean concentrations for complete inhibition of schizont formation were 32.6, 99.5, 148.2 and 190.1 nmol/L, respectively.


CONCLUSIONS
The sensitivity of Plasmodium falciparum to pyronaridine was found to have a tendency of continuous dropping in south Yunnan.
Yang
H
H
Institute of Malaria Prevention and Treatment of Yunnan Province, Simao 665000.
Liu
D
D
Huang
K
K
Zhang
C
C
Li
C
C
D000293:Adolescent; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D004351:Drug Resistance; D006801:Humans; D008137:Longitudinal Studies; D016778:Malaria, Falciparum / Q000188:drug therapy*; D008875:Middle Aged; D009287:Naphthyridines / Q000627:therapeutic use*; D010963:Plasmodium falciparum; D012008:Recurrence; D012680:Sensitivity and Specificity
D000962:Antimalarials; D009287:Naphthyridines; C027871:pyronaridine