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  Contributed Papers: Posters
Diagnosis and Epidemiology

 

Determination of the Sensitivity of the Serial Scraping Method of Intestinal Mucosa in the Diagnosis of Subclinical Coccidiosis


Mauricio De Franceschi1 and Hebe Barrios2
1Departament of Tecnology, 2Departament of Basic Science. Luján National University. Ruta Nacional 5 y Avenida Constitución. 6700. Luján. Argentina. sip@mail.unlu.edu.ar.

In industrial poultry production, serious clinical presentations of coccidiosis (degrees 2, 3 and 4) have opened the way to less intense levels of disease. Subclinical coccidiosis, had particular importance as the disease cannot be controlled, and new forms can develop due to the parasite’s resistance to anticoccidials drugs. Its diagnostic cannot be performed by conventional methods due to the lack of symptoms and lesions, and to small amount of shed oocysts. These are not detected by the coproparasitological analysis. The objective of this work was to demonstrate the sensitivity of Serial Scraping Method of Intestinal Mucosa (SSMIM) in mild cases of the disease as compared to the coproparasitological count using MacMaster chamber. From 1991 to 2001, we performed systematic and weekly diagnosis of coccidiosis in chicken broiler farms in the province of Buenos Aires, Argentina. We collected 486 samples of 6 birds per house and farm. The research of coccidiosis was performed by SSMIM. This technique involved the serial scraping of the mucosa in 1 of every 6 birds of 4 sites in the duodenum, 4 in the jejunum-ileum, and 2 in the ceca. These scrapings were observed in optical microscope under 100-x magnification, which allowed not only the visualization of oocysts, but also other stages of parasite development. At the same time, a pool of fecal matter from 6 birds submitted to the coproparasitological count using a MacMaster chamber. The results showed that, MRSMI allowed the detection of 47 % of the subclinical cases of coccidiosis in the analyzed farms. On the other hand, using the method of parasitological count, only 10.4 % of the samples were positive. We conclude that SSMIM is the best tool to the diagnosis of subclinical coccidiosis due to its higher sensitivity, allowing not only the observation of oocysts, but also the detection of the intracellular development stages before the protozoan excretion starts. This provides an earlier diagnosis of this parasitic disease.

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