Relationship between Antibody-Positive Rate against Plasmodium vivax Circumsporozoite Protein and Incidence of Malaria

The relationship between anti-Plasmodium vivax circumsporozoite protein (CSP) antibody levels and the prevalence of malaria in epidemic areas of South Korea was evaluated. Blood samples were collected from inhabitants of Gimpo-si (city), Paju-si, and Yeoncheon-gun (county) in Gyeonggi-do (province), as well as Cheorwon-gun in Gangwon-do from November to December 2004. Microscopic examinations were used to identify malaria parasites. ELISA was used to quantitate anti-circumsporozoite protein (CSP) antibodies against P. vivax. A total of 1,774 blood samples were collected. The overall CSP-ELISA-positive rate was 7.7% (n=139). The annual parasite incidences (APIs) in these areas gradually decreased from 2004 to 2005 (1.09 and 0.80, respectively). The positive rate in Gimpo (10.4%, 44/425) was the highest identified by CSP-ELISA. The highest API was found in Yeoncheon, followed by Cheorwon, Paju, and Gimpo in both years. The positive rates of CSP-ELISA were closely related to the APIs in the study areas. These results suggest that seroepidemiological studies based on CSP may be helpful in estimating the malaria prevalence in certain areas. In addition, this assay can be used to establish and evaluate malaria control and eradication programs in affected areas.

Seroprevalence of Plasmodium vivax in the Republic of Korea (2003-2005) using Indirect Fluorescent Antibody Test

Plasmodium vivax reemerged in the Republic of Korea (ROK) in 1993, and is likely to continue to affect public health. The purpose of this study was to measure levels of anti-P. vivax antibodies using indirect fluorescent antibody test (IFAT) in border areas of ROK, to determine the seroprevalence of malaria (2003-2005) and to plan effective control strategies. Blood samples of the inhabitants in Gimpo-si, Paju-si, and Yeoncheon-gun (Gyeonggi-do), and Cheorwon-gun (Gangwon-do) were collected and kept in Korea Centers for Disease Control and Prevention (KCDC). Out of a total of 1,774 serum samples tested, the overall seropositivity was 0.94% (n=17). The seropositivity was the highest in Paju-si (1.9%, 7/372), followed by Gimpo-si (1.4%, 6/425), Yeoncheon-gun (0.67%, 3/451), and Cheorwon-gun (0.19%, 1/526). The annual parasite incidence (API) in these areas gradually decreased from 2003 to 2005 (1.69, 1.09, and 0.80 in 2003, 2004, and 2005, respectively). The highest API was found in Yeoncheon-gun, followed by Cheorwon-gun, Paju-si, and Gimpo-si. The API ranking in these areas did not change over the 3 years. The seropositivity of Gimpo-si showed a strong linear relationship with the API of 2005 (r=0.9983, P=0.036). Seropositivity data obtained using IFAT may be useful for understanding malaria prevalence of relevant years, predicting future transmission of malaria, and for establishing and evaluating malaria control programs in affected areas.

Situación epidemiologica de la malaria en Venezuela: Año 2009 / Epidemiological situation of malaria in Venezuela, in 2009

La malaria es la enfermedad parasitaria tropical más importante en el mundo, y la enfermedad contagiosa que más muertes causa a excepción de la tuberculosis. En el año 2009 en Venezuela fueron diagnosticados 36.448 casos, 35.725 originados en el país y 723 importados del exterior, lo cual representó un aumento en la transmisión de 11,5 % (3.688) casos, respecto al registro de 2008, terminando en situación de "alarma" dentro del área de la curva de casos de la enfermedad. Bolívar, Amazonas, Anzoátegui, Sucre, Delta Amacuro y Monagas, fueron los estados de mayor incidencia. En Bolívar, 25 localidades aportan 10.502 casos (34,5% de la incidencia del estado y 29,4% del país). En Amazonas se produce en los menores de 10 años: 32,3% de la incidencia de Plasmodium vivax, 41,6% de Plasmodium falciparum, 78,9% de Plasmodium malariae y 57,1% de infecciones mixtas. Se hace necesario definir el norte del Programa antimalárico, y plantear los objetivos, tomando como base los lineamientos de la OMS/OPS, sea de "control" o de "eliminación". El problema malárico en Venezuela es superable con voluntad política, coordinación entre las autoridades de los niveles Central, Estadal y Local, y la participación de la comunidad. Para ello es imprescindible contar con los recursos: humanos, materiales y económicos necesarios, a fin de realizar una labor eficaz y sostenible en el tiempo, que garantice el éxito de los objetivos planteados.

Malaria is the most important tropical parasitic disease in the world and a contagious disease that causes more deaths than tuberculosis. In the year 2009 in Venezuela 36,448 cases were diagnosed, 35,725 of which originated in the country and 723 imported from abroad. This represents an increase of transmission of 11.5% (3688) cases in relation to that reported of 2008, ending in situation of "alarm" in the area of the curve of cases of the disease. In Bolívar state, 25 sites provided 10,502 cases (34.5% in the incidence of state and 29.4% of the country). In Amazonas state the disease occurred in children under 10 years: 32.3% of the incidence due to Plasmodium vivax, 41.6% to P. falciparum, 78.9% to P. malariae and 57.1% to mixed infections. It is necessary to define the northern malaria program, and raise the objectives, based on the guidelines of the WHO/PAHO, ie., is the program "control" or "elimination." The malaria problem in Venezuela is overcome with political will and lack of coordination between authorities at central, state and local, and community involvement. This requires having the resources: human, material and financial resources, to undertake an effective and sustainable control and elimination program over time, to ensure the success of the objectives.