title: Detection of in-vivo chloroquine resistance in Plasmodium falciparum from Rameswaram Island, a pilgrim centre in southern India.
abstract: Resistance to chloroquine (CQ) in Plasmodium falciparum is one of the main causes of the wide-spread resurgence of malaria in India and a challenge to the effective control of the disease. In the pilgrim centre of Rameswaram Island, malaria has persisted despite the various control measures undertaken over the years. When CQ resistance in Rameswaram was investigated in vivo, recrudescent parasitaemias were observed in 25 (58%) of the 43 study subjects who were given CQ and completed follow-up, all occurring between days 10 and 28 (late treatment failures). The results of the msp(1), msp(2) and glurp genotyping of paired samples of P. falciparum, collected on day 0 and the day of recrudescence from 23 of the apparent treatment failures, indicated that 21 (91%) of the 23 were probably true treatment failures. All of the paired samples harboured parasites with the K76T mutation in their pfcrt genes, and subsequent sequencing of nine day-0 samples revealed the SVMNT haplotype in all nine. This is the first report of in-vivo drug resistance in P. falciparum from Rameswaram Island. Such resistance, which is probably the result of the indiscriminate use of CQ and/or the import of malaria from mainland India, warrants a change in the drug regimen used locally for the first-line treatment of uncomplicated, P. falciparum malaria, to make treatment more effective and slow the development and spread of more foci of CQ resistance.
authors.affiliation: National Institute of Malaria Research, IDVC Field Unit, 332-A Spartan School Road, Panneer Nagar, Mogappair, Chennai - 600 037, India. alexeapen@yahoo.com
authors.forename: A
authors.initials: A
authors.lastname: Eapen
authors.forename: K J
authors.initials: KJ
authors.lastname: Ravindran
authors.forename: H
authors.initials: H
authors.lastname: Joshi
authors.forename: R C
authors.initials: RC
authors.lastname: Dhiman
authors.forename: S
authors.initials: S
authors.lastname: Balavinayagam
authors.forename: P K
authors.initials: PK
authors.lastname: Mallick
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: C
authors.initials: C
authors.lastname: Rajendran
authors.forename: A D
authors.initials: AD
authors.lastname: Selvakumar
authors.forename: A P
authors.initials: AP
authors.lastname: Dash
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000235:genetics; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics
chemical_list: D000953:Antigens, Protozoan; D000962:Antimalarials; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium; C072492:glutamate-rich protein, Plasmodium; D002738:Chloroquine