Falciparum malaria in the north of Laos: the occurrence and implications of the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene haplotype SVMNT.

Abstract

OBJECTIVE:

The Pfcrt-gene encodes a transmembrane protein located in the Plasmodium falciparum digestive vacuole. Chloroquine resistant (CQR) strains of African and Southeast Asian origin carry the Pfcrt-haplotype (c72-76) CVIET, whereas most South American and Papua New Guinean CQR stains carry the SVMNT haplotype.

METHOD:

Eighty-eight samples from an area with reported in vivo Chloroquine and in vitro Amodiaquine-resistance were screened for the K76T mutation and their Pfcrt-haplotype (c72-76) using a new SSOP-ELISA.

RESULTS:

Hundred percent of the analysed samples showed the K76T mutation which is highly associated with in vivo drug failure. This very high rate of a CQR-marker is alarming in an area were CQ is still used as first line drug. The distribution of the three main Pfcrt-haplotypes was as follows: 68% CVIET, 31% SVMNT, 0% CVMNT.

CONCLUSIONS:

These data show, for the first time, the South American/PNG -haplotype (SVMNT) on mainland Southeast Asia. SVMNT-haplotype and others might be associated with a decreased efficacy of Amodiaquine and could therefore be potential markers for of amodiaquine resistance (AQR). If there is a correlation between AQR and the SVMNT-haplotype as suggested, 31% prevalence of a potential resistance marker is cause for concern.

• Authors: Sabine Dittrich, Michael Alifrangis, Jörg M Stohrer, Vonthalom Thongpaseuth, Viengxay Vanisaveth, Rattanaxay Phetsouvanh, Samlane Phompida, Insaf F Khalil, Tomas Jelinek
• Journal: Tropical medicine & international health : TM & IH (Trop Med Int Health) Vol. 10 Issue 12 Pg. 1267-70 (Dec 2005) ISSN: 1360-2276 [Print] England
• PMID: 16359407 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antimalarials
• Membrane Proteins
• Membrane Transport Proteins
• PfCRT protein, Plasmodium falciparum
• Protozoan Proteins
• Chloroquine

Topics

• Adolescent
• Adult
• Aged
• Animals
• Antimalarials (therapeutic use)
• Child
• Child, Preschool
• Chloroquine (therapeutic use)
• Cross-Sectional Studies
• Drug Resistance (genetics)
• Enzyme-Linked Immunosorbent Assay (methods)
• Female
• Haplotypes (genetics)
• Humans
• Laos (epidemiology)
• Malaria, Falciparum (drug therapy, epidemiology, genetics)
• Male
• Membrane Proteins (genetics)
• Membrane Transport Proteins
• Middle Aged
• Mutation (genetics)
• Nucleic Acid Hybridization (methods)
• Plasmodium falciparum (genetics)
• Protozoan Proteins
• Treatment Failure