# name
The Incidence and Differential Seasonal Patterns of Plasmodium
                vivax Primary Infections and Relapses in a Cohort of Children in
                Papua New Guinea

# metadata.dc.description.abstract[].value
Plasmodium vivax has the ability to relapse from dormant
                parasites in the liver weeks or months after inoculation,
                causing further blood-stage infection and potential onward
                transmission. Estimates of the force of blood-stage infections
                arising from primary infections and relapses are important for
                designing intervention strategies. However, in endemic settings
                their relative contributions are unclear. Infections are
                frequently asymptomatic, many individuals harbor multiple
                infections, and while high-resolution genotyping of blood
                samples enables individual infections to be distinguished,
                primary infections and relapses cannot be identified. We develop
                a model and fit it to longitudinal genotyping data from children
                in Papua New Guinea to estimate the incidence and seasonality of
                P vivax primary infection and relapse. The children, aged one to
                three years at enrolment, were followed up over 16 months with
                routine surveys every two months. Blood samples were taken at
                the routine visits and at other times if the child was ill.
                Samples positive by microscopy or a molecular method for species
                detection were genotyped using high-resolution capillary
                electrophoresis for P vivax MS16 and msp1F3, and P falciparum
                msp2. The data were summarized as longitudinal patterns of
                success or failure to detect a genotype at each routine
                time-point (eg 001000001). We assume that the seasonality of P
                vivax primary infection is similar to that of P falciparum since
                they are transmitted by the same vectors and, because P
                falciparum does not have the ability to relapse, the seasonality
                can be estimated. Relapses occurring during the study period can
                be a consequence of infections occurring prior to the study: we
                assume that the seasonal pattern of primary infections repeats
                over time. We incorporate information from parasitological and
                entomology studies to gain leverage for estimating the
                parameters, and take imperfect detection into account. We
                estimate the force of P vivax primary infections to be 11.5
                (10.5, 12.3) for a three-year old child per year and the mean
                number of relapses per infection to be 4.3 (4.0, 4.6) over 16
                months. The peak incidence of relapses occurred in the two month
                interval following the peak interval for primary infections: the
                contribution to the force of blood-stage infection from relapses
                is between 71% and 90% depending on the season. Our estimates
                contribute to knowledge of the P vivax epidemiology and have
                implications for the timing of intervention strategies targeting
                different stages of the life cycle.

# metadata.dc.relation.isformatof[].value
Reproducció del document publicat a:
                http://dx.doi.org/10.1371/journal.pntd.0004582

# metadata.dc.relation.ispartof[].value
PLoS Neglected Tropical Diseases, 2016, vol. 10, num. 5, p.
                e0004582

# metadata.dc.source[].value
Articles publicats en revistes (ISGlobal)

# metadata.dc.title[].value
The Incidence and Differential Seasonal Patterns of Plasmodium
                vivax Primary Infections and Relapses in a Cohort of Children in
                Papua New Guinea