RESUMO
The study of nematodes requires availability of nematode specimens and their population densities in plants and soil. This can be achieved using adequate sampling schemes and extraction methods. In this chapter, the most common and suitable sampling and extraction procedures and equipment are described. These include the use of Baermann's funnels, Cobb's decanting and sieving, floating methods such as the Oostenbrink method and Fenwick can, elutriators such as Seinhorst methods, centrifugation methods including that of Coolen, and mechanical and enzymatic maceration. The combination of different methods for cleaning the nematode suspensions is described, such as Cobb's sieving with Baermann's funnels or centrifugation, and for cysts combining Seinhorst's elutriator or Fenwick can with the alcohol methods. Methods for extraction of eggs and/or juveniles of cyst and egg mass forming nematodes, to be used as inoculum or to ascertain egg viability, are also described. Only little information is also noted on the use of molecular tools to identify and quantify nematode populations in soil and roots.
Assuntos
Nematoides , Tylenchida , Animais , Plantas , Solo , Raízes de Plantas/parasitologiaRESUMO
La leptospirosis es una antropozoonosis de distribución mundial, con mayor incidencia en países tropicales. En Venezuela los casos son registrados en el sistema nacional de vigilancia para enfermedades íctero-hemorrágicas, con poca publicación sobre los aspectos clínicos y epidemiológicos de la enfermedad, por lo tanto el objetivo fue establecer las características epidemiológicas, clínicas, y diagnósticas de la leptospirosis en el Estado Aragua. El diseño fue un estudio epidemiológico transversal que describe los casos confirmados y probables de leptospirosis, obtenidos a partir del programa nacional de Síndrome Febril Ictérico Hemorrágico. Como resultados de 533 casos reportados desde enero del 2011 hasta julio del 2013, 233 (43,7%) fueron probables y 68 (12,75%) confirmados de leptospirosis. La tasa cruda de incidencia acumulada de leptospirosis por 100.000 habitantes más elevada en el periodo de estudio ocurrió en el año 2012, con un valor de 2,94 y los municipios con mayor tasa fueron Bolívar (7,9) y Sucre (5,2). Los factores de riesgo más reportados fueron: presencia de roedores en vivienda con 63,2%, marzo y abril, los meses con menor pluviosidad presentaron la menor frecuencia de casos. Los síntomas más frecuentes en los casos confirmados fueron fiebre 75%, cefalea 61,8%, ictericia 55,9%, vómitos 54,4%, dolor abdominal 47,1%, diarrea 35,3%. Cefalea, artralgia, mialgia y dolor retro-ocular predominaron en mayores a 10 años. 12,8% de los casos de leptospirosis se diagnosticaron por PCR en sangre, 28% PCR en orina, 45,2% por MAT.
Leptospirosis is a worldwide distribution anthropozoonosis, with a higher incidence in tropical countries. In Venezuela, the cases are registered in the national surveillance system for the ictero-hemorrhagic diseases, with little documentation upon clinical and epidemiological aspects of the disease; hence, the aim of this study was to establish epidemiologic, clinical and diagnostic characteristics of leptospirosis in Aragua state. It was a Cross sectional epidemiological study where probable and confirmed cases of leptospirosis were described, obtained from the febril icterohemorrhagic national surveillance program. From 533 cases reported since January of 2011 to July of 2013, 233 (43,79%) were probable cases, 68 (12,75%) were confirmed for leptospirosis. The highest cumulative incidence crude rate of leptospirosis per 100.000 inhabitants of the study period occurred in 2012 with 2,94. Bolivar (7,9%) and Sucre (5,2%) were the municipalities with the highest incidence rate. The main risk factors were: the presence of rodents in houses 63,2%, march and april were the months with the lowest rainfall which showed the fewest number of cases. The most frequent symptoms in confirmed cases were fever (75%), headaches (61,8%), jaundice (55,9%), vomiting (54,4%), abdominal pain (47,1%), diarrhea (35,3%), were the most frequent symptoms among confirmed cases. Headache, joint pain, myalgia, and retroocular pain, were significantly more frequent in ages over 10 years. 12,8% of the caseswere diagnosed by PCR based on blood, 28% by PCR based on urine, 45,2% by MAT.
RESUMO
Se presenta un perfil del estado actual de la nematología agrícola en Venezuela incluyendo una lista de las 115 especies de nematodos fitoparasíticos identificadas. Las especies más dañinas parecen ser Bursaphelenchus (=Rhadinaphelenchus) cocophillus, Ditylenchus dipsaci, Globodera rostochiensis, G.pallida, Meloidogyne incognita, M.javanica, M.exigua, Mhapla, Pratylenchus brachyurus, P.penetrans, P.scribneri, P.zeae, Radopholus similis, Rotylenchulus reniformis y Tylenchulus semipenetrans. Se discuten brevemente los efectos dañinos de Meloidogyne spp. y de otros nematodos fitroparasíticos