Fig. 6

Course of molecular target detection in infected subject. A patient infected with P. falciparum by CHMI developed late-onset, symptomatic, blood-smear positive (D25) peripheral infection and was treated 25 days post-challenge with a standard treatment course of atovaquone–proguanil (A/P). Following treatment, symptoms resolved but the patient continued to display 18S rRNA positivity. pfs25 and PF3D7_0630000 RT-PCRs were performed and demonstrated a period of gametocyte (Gams)-specific mRNA positivity during the secondary wave of 18S rRNA positivity, consistent with gametocytaemia. The 18S rRNA-based results were unaffected by DNase treatment (not shown). Stage-specific 18S rRNA conversion factors were used to estimate parasite densities (7.4 × 10³ copies of 18S rRNA/asexual ring left of vertical line; 4.5 × 10⁴ copies of 18S rRNA/mature gametocyte right of vertical line) and standard curve of pure cultured gametocytes diluted into whole blood was used for quantification of gametocyte-specific qRT-PCRs. Primaquine (PQ, 45 mg oral) was administered one time 45 days post-challenge. ND, not detected; asterisk pfs25 RT-PCR not performed