Background: Chloroquine is the first line treatment for P. vivax malaria in India, but chloroquine resistance is increasing. Monitoring of antimalarial efficacy is essential, but in P. vivax infections the assessment of treatment efficacy is confounded by relapse from the dormant liver stages. Resistance to CQ was first reported from Papua New Guinea in 1989, followed by different endemic regions from Southeast Asia. Reports of CQ treatment failure and resistance have been reported from different regions of India, viz., Mumbai, Mathura, South Bihar, Kolkata, and North Odisha.
Objectives: To determine the extent of chloroquine resistance in P. vivax malaria in Indian subcontinent.
Methods:
We searched PubMed database by using search terms “India” AND “malaria” AND “vivax” AND “chloroquine” AND “resistance” OR “resistant” to identify studies published in English between January 1995 and December 2021, which investigated chloroquine efficacy of P. vivax malaria in Indian subcontinent. The initial search yielded 101 articles, 56 studies out of 101 were eligible. However, 12 studies were fulfilling the inclusion criteria for the review. Results from eligible studies were pooled using standardized methodology.
Results:
We identified 12 eligible studies involving 1,739 patients including 3 case reports with 4 patients. Among in-vivo efficacy studies, early treatment failure for chloroquine was found in 5/1735 (0.28%) patients, Late clinical failure in 6/1735 (0.34%) patients, late parasitological failure in 17/1735 (0.97%) patients.
Conclusion: Prevalence of chloroquine resistance in P. vivax is low in India. However, continued surveillance and monitoring is required to identify emergence of chloroquine resistance.