ABSTRACT
A longitudinal study of malaria vectors aiming to describe the intensity of transmission was carried out in five villages of Southern Venezuela between January 1999-April 2000. The man-biting, sporozoite and entomological inoculation rates (EIR) were calculated based on 121 all-night collections of anophelines landing on humans, CDC light traps and ultra violet up-draft traps. A total of 6,027 female mosquitoes representing seven species were collected. The most abundant species were Anopheles marajoara Galvão & Damasceno (56.7 percent) and Anopheles darlingi Root (33 percent), which together accounted for 89.7 percent of the total anophelines collected. The mean biting rate for An. marajoara was 1.27 (SD + 0.81); it was 0.74 (SD + 0.91) for An. darlingand 0.11 (SD + 0.10) for Anopheles neomaculipalpus Curry and the overall biting rate was 2.29 (SD + 1.06). A total of 5,886 mosquitoes collected by all three methods were assayed by ELISA and 28 pools, equivalent to 28 mosquitoes, yielded positive results for Plasmodium spp. CS protein. An. neomaculipalpus had the highest sporozoite rate 0.84 percent (3/356), followed by An. darlingi 0.82 percent (16/1,948) and An. marajoara 0.27 percent (9/3,332). The overall sporozoite rate was 0.48 percent (28/5,886). The rates of infection by Plasmodium species in mosquitoes were 0.37 percent (22/5,886) for Plasmodium vivax(Grassi & Feletti) and 0.10 percent (6/5,886) for Plasmodium falciparum (Welch). The estimated overall EIR for An. darling was 2.21 infective bites/person/year, 1.25 for An. marajoara and 0.34 for An. neomaculipalpus. The overall EIR was four infective bites/person/year. The biting rate, the sporozoite rate and the EIR are too low to be indicators of the efficacy of control campaigns in this area.
Subject(s)
Animals , Female , Anopheles/parasitology , Insect Vectors/parasitology , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Anopheles/classification , Enzyme-Linked Immunosorbent Assay , Insect Vectors/classification , Longitudinal Studies , VenezuelaABSTRACT
Un estudio comparativo de diagnósticos de gota gruesa y extendido para malaria entre los niveles Regional y Central fue realizado con la finalidad de determinar su concordancia. De las 306.810 muestras tomadas y examinadas durante el año 2003 a nivel nacional, fueron evaluadas 19.414,representando 34% de las positivas y 3% de las negativas. La clasificación correcta de los diagnósticos maláricos fue de 99,6%, con concordancias de k=0,99 (óptima) para la evaluación de los diagnósticos y de k=0,98 (óptima) para las especies Plasmodium vivax y Plasmodium falciparum. Cuando se presentaron infecciones mixtas la concordancia alcanzó k=0,66 (buena).