Comparison of five parasitological techniques for laboratory diagnosis of Balantidium coli cysts

Abstract

Balantidium coli is a protozoon that can cause dysentery in humans, pigs and nonhuman primates, with zoonotic potential. In the literature, there is still little information on the effectiveness of different laboratory techniques for diagnosing this disease. This study compared and evaluated the performance of the Lutz, modified Ritchie, Faust, modified Sheather and direct examination techniques for detecting cysts of this protozoon. Between 2012 and 2014, 1905 fecal samples were collected from captive animals in the state of Rio de Janeiro. Of these, 790 were obtained from the rectum of pigs and 1115 from enclosures occupied by nonhuman primates. B. coli cysts were most evident through direct examination (22.4% of the samples) and the Lutz technique (21%). Fair agreement (Kappa = 0.41; p < 0.05) was observed only between direct examination and Lutz. The flotation techniques (Faust and modified Sheather) did not show good recovery of cysts. A statistically significant difference (p < 0.05) in the frequency of cysts between pigs and nonhuman primates could only be observed through direct examination and the Lutz technique. The most efficient method for diagnosing this parasitosis was seen to an association between direct examination and the spontaneous sedimentation technique.Keywords: Balantidium coli, parasitological techniques, cysts, laboratory diagnosis. ResumoBalantidium coli é um protozoário que pode determinar disenteria em humanos, suínos e primatas não humanos apresentando potencial zoonótico. Na literatura ainda são escassas as informações sobre a eficiência das diferentes técnicas laboratoriais para o diagnóstico dessa parasitose. Este estudo comparou e avaliou o desempenho das técnicas de Lutz, Ritchie modificada, Faust, Sheather modificada e do exame direto para a detecção de cistos desse protozoário. Entre 2012 e 2014, foram coletadas 1905 amostras fecais de animais cativos no Estado do Rio de Janeiro. Dessas, 790 foram obtidas da ampola retal de suínos e 1115 dos recintos de primatas não humanos. Cistos de B. coli foram 22,4 % mais evidenciados pelo exame direto; e pela técnica de Lutz, 21% das amostras. Concordância regular (Kappa = 0,41; p < 0,05) foi observada somente entre exame direto e Lutz. As técnicas de flutuação, Faust et al. e Sheather modificada não apresentaram boa recuperação dos cistos. Diferença estatística significativa (p < 0,05) na frequência de cistos entre suínos e primatas não humanos pode ser observada somente no exame direto e na técnica de Lutz. A metodologia mais eficiente para diagnóstico dessa parasitose foi observada pela associação do exame direto e da técnica de sedimentação espontânea.Palavras-chave: Balantidium coli, técnicas parasitológicas, cistos, diagnóstico laboratorial.

Occurrence of gastrointestinal parasitic diseases of swine in different production phases in commercial pig farms from the State of Santa Catarina, southern Brazil

“…The former group of authors Steffen et al (2010), used centrifugation/flotation methods, whereas the latter research group Antunes et al (2011), examined the stool samples using the fecal sedimentation assay. In a study published by Barbosa et al (2016) in which the performance of different parasitological techniques for the search of Balantidium spp. in fecal samples were assessed, the Sheather method presented the lowest sensitivity compared with other methods.…”

“…Despite the fact that this ciliate is considered a commensal organis of the gastrointestinal tract of pigs, it may cause focal lesions in the intestines of swine as a opportunistic pathogen. Its major importance is related to public health since it may cause enteric disease in humans (Barbosa et al, 2016).…”

“…In addition to these parasites, pigs are considered the main reservoir of the ciliate Balantidium coli, which can infect humans, especially those who work in agriculture (Barbosa et al, 2016). Humans are also considered reservoirs of the protozoan parasite Entamoeba spp.…”

Comparison between five coprological methods for the diagnosis of Balantidium coli cysts in fecal samples from pigs

“…Weng et al [6] used direct methods and flotation solution with sodium chloride for the diagnosis. On the other hand, Sanchez [7] using direct examination for diagnosing B. coli in human stool samples, and Barbosa et al [8] compared five coprological techniques for the diagnosis of B. coli cysts in fecal samples from pigs and non-human primates. Azevedo et al [9] used four parasitological techniques to study intestinal parasites in fecal samples from people from Brazil.…”

“…Therefore, laboratory diagnosis plays an important role in the diagnosis of these infections [10]. Despite the existence of numerous quantitative and qualitative techniques for parasitological examination of feces, there is very little information about studies that have evaluated the performance of diagnostic methods to identify B. coli Available at www.veterinaryworld.org/Vol.14/April-2021/9.pdf cysts [8]. A reference technique with a high percentage of precision and security is not generally available for parasitological studies, especially to detecting gastrointestinal parasites [11].…”