Epidemiology of ultra-low density malaria infections and their relevance for control and elimination
Epidemiology of ultra-low density malaria infections and their relevance for control and elimination
Objectives
The specific objectives are:
1. To measure the proportion of parasites missed by microscopy and standard PCR in field surveys.
2. To examine how host age and levels of malaria endemicity influence this proportion.
3. To determine whether ultra-low density infections carry gametocytes and estimate their contribution to the human reservoir of infection to mosquitoes.
4. To find ways to increase the sensitivity of parasite detection in large scale field surveys.
Approach: Ultra-sensitive nucleic acid based detection methods for P. falciparum and P. vivax will be developed by targeting highly repetitive DNA markers and highly expressed stage-specific transcripts. Ultra-low density infections will be studied in different endemic settings and age groups, for P. vivax we compare PNG (high transmission), Thailand (low transmission) and Brazil (close to elimination). Gametocyte detection and genotyping in both species will be used for estimating the transmission potential and transmission dynamics.