Longitudinal survey of Plasmodium falciparum infection in Vietnam: characteristics of antimalarial resistance and their associated factors.
Plasmodium falciparum is the main cause of human malaria and is one of the important pathogens causing high rates of morbidity and mortality. The total number of malaria patients in Vietnam has gradually decreased over the last decade. However, the spread of pathogens with drug resistance remains a significant problem. Defining the trend in genotypes related to drug resistance is essential for the control of malaria in Vietnam. We undertook a longitudinal survey of Plasmodium falciparum malaria in 2001, 2002, and 2005 to 2007. The pfcrt, pfmdr1, pfdhfr, and pfdhps genes were analyzed by sequencing; and correlations by study year, age, gender, and genotype were identified statistically. The ratio of the chloroquine resistance genotype pfcrt 76T was found to have decreased rapidly after 2002. High numbers of mutations in the pfdhfr and pfdhps genes were observed only in 2001 and 2002, while the emergence of parasites with a new K540Y mutation in the P. falciparum dihydropteroate synthetase (PfDHPS) was observed in 2002. For males and those in younger age brackets, a correlation between vulnerability to P. falciparum infection and strains with pfcrt 76K or strains with decreased numbers of mutations in pfdhfr and pfdhps was demonstrated. The parasites with pfcrt 76T exhibited a greater number of mutations in pfdhfr and pfdhps.
Isozumi
Rie
R
Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
Uemura
Haruki
H
Le
Duc Dao
DD
Truong
Van Hanh
VH
Nguyen
Duc Giang
DG
Ha
Viet Vien
VV
Bui
Quang Phuc
QP
Nguyen
Van Tuan
VT
Nakazawa
Shusuke
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology*; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D017354:Point Mutation; D015800:Protozoan Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
D000962:Antimalarials; D015800:Protozoan Proteins