Abstract
The measurement of recent malaria exposure can support malaria control efforts. This study evaluated serological responses to an in-house Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) expressed in a Baculovirus system as sero-marker of recent exposure to P. vivax (Pv) in the Peruvian Amazon. In a first evaluation, IgGs against PvMSP8 and PvMSP10 proteins were measured by Luminex in a cohort of 422 Amazonian individuals with known history of Pv exposure (monthly data of infection status by qPCR and/or microscopy over five months). Both serological responses were able to discriminate between exposed and non-exposed individuals in a good manner, with slightly higher performance of anti-PvMSP10 IgGs (area under the curve AUC = 0.78 [95% CI = 0.72–0.83]) than anti-PvMSP8 IgGs (AUC = 0.72 [95% CI = 0.67–0.78]) (p = 0.01). In a second evaluation, the analysis by ELISA of 1251 plasma samples, collected during a population-based cross-sectional survey, confirmed the good performance of anti-PvMSP8 IgGs for discriminating between individuals with Pv infection at the time of survey and/or with antecedent of Pv in the past month (AUC = 0.79 [95% CI = 0.74–0.83]). Anti-PvMSP8 IgG antibodies can be considered as a good biomarker of recent Pv exposure in low-moderate transmission settings of the Peruvian Amazon.
Highlights
As observed in different malaria-endemic countries, important reductions in malaria incidence can be achieved with intensive and comprehensive control measures [1]
After successfully producing a recombinant Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) protein in our laboratory using the Baculovirus expression system, we evaluated the performance of IgG responses against this protein in discriminating between individuals with recent P. vivax infection and those without infection
The cross-validated receiver operating characteristic (ROC) analysis showed a good performance of serological responses against PvMSP8 for detecting P. vivax recent exposure (area under the curve (AUC = 0.72 [95% confidence intervals (CIs) = 0.67–0.77]), which was slightly lower than the performance of anti-P. vivax Merozoite Surface Protein-10 (PvMSP10) (AUC = 0.78 [95% CI = 0.72–0.83]; p = 0.01)
Summary
As observed in different malaria-endemic countries, important reductions in malaria incidence can be achieved with intensive and comprehensive control measures [1]. The design and study of smaller protein fragments or peptides of this protein, antigenic diversity, and performance upgrade in conjunction with other SEMs in terms of sensitivity, specificity, positive and negative likelihood ratio, misclassification error rate, and misclassification cost rates, according to different use case scenarios (prevalence) and quality assurance of protein production, should all be considered before its escalation and implementation as a point-of-contact antibody test in an ELISA or rapid diagnostic test format at local health facilities Another limitation of the study was that we were unable to evaluate the performance of PvMSP8 as SEM in classifying symptomatic and asymptomatic individuals due to the low number of symptomatic cases. It would be interesting to evaluate the functional role of antibodies against these proteins in ex-vivo P. vivax and in-vitro P. falciparum invasion studies
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
