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.