One of your patients who was diagnosed to have malaria was treated with chloroquine and doxycycline for 7 days. Though his fever subsided in a few days after staing the treatment, his peripheral smear showed plasmodium gametocytes even after 7 days of treatment. As per WHO guidelines this type of drug resistance is:

The WHO classification of antimalarial drug resistance is given below: S.sensitive - If asexual parasite have cleared by day 6 from the beginning of treatment without subsequent recrudescence until 28 days. R1 - Low Grade resistance - Recrudescence of infection between 7 - 28 day of completing treatment. R2 - High grade resistance - Reduction of parasitemia by more than 75% at 48 hours of completing treatment but failure to clear the organism within 7 days. R3 - Parasitemia does not fall by more than 75% within 48 hours of completing treatment and there is no subsequent clearance of asexual parasites. Ref: O.P.Ghai, Edition - 6, Page - 240.