Early treatment failure in concurrent dengue and mixed malaria species infection with suspected resistance to artemisinin combination therapy from a tertiary care center in Delhi: a case report.

Background: Concurrent dengue and mixed malaria infections in a single patient present with overlapping clinical manifestations which pose a diagnostic challenge and management dilemma in areas of common endemicities.

Methods: We report a case of a young male who tested positive for both and along with dengue infection. He showed signs of early treatment failure to artemisinin combination therapy (artesunate with sulfadoxine+pyrimethamine). Molecular analysis for the drug resistance genes viz: chloroquine resistance (), multidrug resistance (), sulfadoxine (), pyrimethamine (), and artemisinin resistance () was performed.

Results: A rise in parasitemia from <2% to 5% was observed after 3 days of treatment. Mutations in , , , and genes were detected as a possible cause of treatment failure.

Conclusion: Increased severity, overlapping symptoms, and suspected resistance to treatment warrants a multidimensional diagnostic approach and diligent therapeutic monitoring.