Format

Send to

Choose Destination
J Infect Dis. 2019 Nov 4. pii: jiz557. doi: 10.1093/infdis/jiz557. [Epub ahead of print]

Growth Rate of Plasmodium falciparum: Analysis of Parasite Growth Data from Malaria Volunteer Infection Studies.

Author information

1
QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
2
Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
3
Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, WA, USA.
4
Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
5
School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
6
Q-Pharm Pty Ltd, Brisbane, QLD, Australia.

Abstract

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 (PMR48), PMR per life-cycle (PMRLC), 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), PMR48 was 31.9 (95% CI: 28.7-35.4), PMRLC 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; PMR48 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; PMR48 8.6, 95% CI: 7.3-10.1).

CONCLUSION:

Parasite growth rates were similar across different IBSM studies and higher than infections induced by sporozoite.

KEYWORDS:

Plasmodium falciparum 3D7; CHMI; Parasite growth rate; induced blood stage malaria; statistical models; volunteer infection studies

PMID:
31679015
DOI:
10.1093/infdis/jiz557

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center