Assessing malaria transmission in a low endemicity area of north-western Peru

Malaria Journal

Research

Irene S Soares¹  Mayne O Pereira¹  Michael Theisen²  Jackie Cook³  Umberto D’Alessandro⁴  Annette Erhart⁵  Juan Contreras-Mancilla⁶  Oscar J Ponce⁶  Alejandro Llanos-Cuentas⁶  Veronica Soto⁶  Dionicia Gamboa⁷  Angel Rosas-Aguirre⁸  Niko Speybroeck⁹  Edwar Pozo^1,10 

[1] Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil;Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, Denmark;Department of Infectious Diseases, Copenhagen University Hospital and Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark;Department of Medicine Solna, Karolinska Institutet, Malaria Research Unit, Stockholm, Sweden;Disease Control and Elimination, Medical Research Council Unit, Fajara, The Gambia;Institute of Tropical Medicine, 2000, Antwerp, Belgium;Institute of Tropical Medicine, 2000, Antwerp, Belgium;Instituto de Medicina Tropical, Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru;Instituto de Medicina Tropical, Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru;Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru;Instituto de Medicina Tropical, Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru;Institute of Tropical Medicine, 2000, Antwerp, Belgium;Research Institute of Health and Society (IRSS), Université catholique de Louvain, 1200, Brussels, Belgium;Sub-region de Salud Luciano Castillo Coloma, Sullana, Peru;

关键词: Malaria transmission intensity;    Low endemicity;    Elimination;    Polymerase chain reaction;    Serology;    Peru;   

DOI  :  10.1186/1475-2875-12-339

 received in 2013-05-10, accepted in 2013-09-16,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundWhere malaria endemicity is low, control programmes need increasingly sensitive tools for monitoring malaria transmission intensity (MTI) and to better define health priorities. A cross-sectional survey was conducted in a low endemicity area of the Peruvian north-western coast to assess the MTI using both molecular and serological tools.MethodsEpidemiological, parasitological and serological data were collected from 2,667 individuals in three settlements of Bellavista district, in May 2010. Parasite infection was detected using microscopy and polymerase chain reaction (PCR). Antibodies to Plasmodium vivax merozoite surface protein-119 (PvMSP119) and to Plasmodium falciparum glutamate-rich protein (PfGLURP) were detected by ELISA. Risk factors for exposure to malaria (seropositivity) were assessed by multivariate survey logistic regression models. Age-specific antibody prevalence of both P. falciparum and P. vivax were analysed using a previously published catalytic conversion model based on maximum likelihood for generating seroconversion rates (SCR).ResultsThe overall parasite prevalence by microscopy and PCR were extremely low: 0.3 and 0.9%, respectively for P. vivax, and 0 and 0.04%, respectively for P. falciparum, while seroprevalence was much higher, 13.6% for P. vivax and 9.8% for P. falciparum. Settlement, age and occupation as moto-taxi driver during previous year were significantly associated with P. falciparum exposure, while age and distance to the water drain were associated with P. vivax exposure. Likelihood ratio tests supported age seroprevalence curves with two SCR for both P. vivax and P. falciparum indicating significant changes in the MTI over time. The SCR for PfGLURP was 19-fold lower after 2002 as compared to before (λ1 = 0.022 versus λ2 = 0.431), and the SCR for PvMSP119 was four-fold higher after 2006 as compared to before (λ1 = 0.024 versus λ2 = 0.006).ConclusionCombining molecular and serological tools considerably enhanced the capacity of detecting current and past exposure to malaria infections and related risks factors in this very low endemicity area. This allowed for an improved characterization of the current human reservoir of infections, largely hidden and heterogeneous, as well as providing insights into recent changes in species specific MTIs. This approach will be of key importance for evaluating and monitoring future malaria elimination strategies.

【 授权许可】

CC BY   
© Rosas-Aguirre et al.; licensee BioMed Central Ltd. 2013