Background Growth rate of malaria parasites in the blood of infected subjects is an important measure of efficacy of drugs and vaccines. Methods We used log-linear and sine-wave models to estimate the parasite growth rate of the 3D7 strain of Plasmodium falciparum using data from 177 subjects from 14 induced blood stage malaria (IBSM) studies conducted at QIMR Berghofer. We estimated parasite multiplication rate per 48 hour (PMR 48 ), PMR per life-cycle (PMR LC ), and parasite life-cycle duration. We compared these parameters to those from studies conducted elsewhere with infections induced by IBSM (n=66), sporozoites via mosquito bite (n=336) or injection (n=51). Results The parasite growth rate of 3D7 in QIMR Berghofer studies was 0.75/day (95% CI: 0.73–0.77/day), PMR 48 was 31.9 (95% CI: 28.7–35.4), PMR LC was 16.4 (95% CI: 15.1–17.8) and parasite life-cycle was 38.8 hour (95% CI: 38.3–39.2 hour). These parameters were similar to estimates from IBSM studies elsewhere (0.71/day, 95% CI: 0.67–0.75/day; PMR 48 26.6, 95% CI: 22.2–31.8), but significantly higher ( P < 0.001) than in sporozoite studies (0.47/day, 95% CI: 0.43–0.50/day; PMR 48 8.6, 95% CI: 7.3–10.1). Conclusions Parasite growth rates were similar across different IBSM studies and higher than infections induced by sporozoite.
【저자키워드】 statistical models, CHMI, Volunteer infection studies, Parasite growth rate, Plasmodium falciparum 3D7, induced blood stage malaria,