Modelling the risk of P. vivax infections through microsatellites genotyping and Circumsporozoite protein (CSP) ELISA

P. vivax is the most widespread among the four malaria species but little is known about the dynamics of infection in the human population and how the reservoir is maintained. The proposed project specifically targets the current lack of tool for a reliable discrimination between new and recrudescent/relapses in P.vivax infections, the main bottleneck to further understanding P.vivax epidemiology. As current molecular and serological techniques have each their own limitations, modelling techniques may be helpful in establishing whether a recurrent P. vivax infection is a new one or a relapse/recrudescence. A probabilistic approach to modulate the values of chosen parameters will be used and the adequacy of the model fitting the actual data evaluated. For this purpose, we will use blood samples collected on a cohort of P. vivax patients followed up for 2 years. Multilocus genotyping using microsatellites and ELISA detecting antibodies against the circumsporozoite protein will be performed on the available samples. Modelling will be done using R software, and will combine simultaneously different types of epidemiological, molecular and serological parameters measured at population as well as individual level in order to estimate the probability that any P.vivax recurrence with a given genotype is a new infection (rather than a recrudescence/relapse).