Participants were treated with anti-malarial drugs as soon as parasites were detected by TBS. Treatment consisted of chloroquine (1,500 mg chloroquine base provided orally in divided doses: 600 mg initially followed by 450 mg given 24 and 48 hours later) and primaquine (two 15 mg doses given once per day for 14 days). Volunteers were provided with intravenous fluids, analgesics, and antiemetics as needed. Signs and symptoms consistent with malaria were assessed by clinical examination and were graded 1-5 according to their severity following the National Cancer Institute (NCI) criteria for adverse events (CTCAE ) as follows: Grade 1 = Low, Grade 2 = Moderate, Grade 3 = Severe, Grade 4 = Serious, and Grade 5 = Death. Pruritus was graded from 1 to 3 (1 = mild or localized; 2 = intense or widespread; and 3 = intense or widespread and interfering with activities of daily living). Because there is no common terminology AE agreement, for edema and erythema following mosquito bites, an adaptation from the CTCAE v 3 for "injection site/extravasation changes" was used as follows: Grade 1 = local pain/edema and erythema; Grade 2 = pain or swelling with inflammation or phlebitis; Grade 3 = ulceration or necrosis. Pain was scored as Grade 1 = mild not interfering with function; Grade 2 = moderate pain (pain or analgesics interfering with function, but not interfering with activities of daily living); Grade 3 = severe pain (pain or analgesics severely interfering with activities of daily living).