Occurrence of Bovine Cysticercosis in Two Regions of the State of Tocantins-Brazil and the Importance of Pathogen Identification

Abstract

Bovine cysticercosis, caused by Taenia saginata metacestodes, is the cause of significant economic losses to the meat production chain by condemnation and downgrading of infected carcasses. It is also a public health issue causing human taeniasis. This study evaluated the occurrence of bovine cysticercosis at the meat inspection procedures in slaughterhouses of south and north regions of the Tocantins State in Brazil. Specimens identified as cysts of T. saginata were collected and analyzed by molecular (PCR) and histopathological techniques. The cysts were collected from March to December of 2010 in slaughterhouses located in the cities of Alvorada (South) and Araguaína (North). The frequency of cystic lesions during the study was 0.033% (53/164,091) with 69.81% of calcified lesions and 30.9% of live cysts at meat inspection. From 14 samples submitted to molecular analysis, 28.57% (4/14) were positive for T. saginata. The histopathological analysis of the non-T. saginata samples showed lesions suggestive of granuloma and hydatid disease. The results indicated that the identification of the etiological agent is difficult by macroscopic inspection, emphasizing the need to associate specific diagnostic methods at meat inspection in abattoirs. In addition, species-specific PCR would be an effective tool for diagnosis, monitoring, and identifying cysticercosis, assisting the conventional tests.

A rare case of human taeniasis caused by Taenia saginata with species undetermined cysticercosis

“…However, our study suggested that patients with taeniasis accompanied by cysticercosis may need whole-genome analysis to further ascertain whether T. saginata is also responsible for causing human cysticercosis. Despite the widespread availability of molecular identification methods, often tested on proglottids' samples, the sensitivity of detection in cyst samples may be lowered due to DNA degradation within cysts (Figueiredo et al ., 2019 ). Many researchers have reported various mitochondrial/nuclear gene discordances in specimens, indicating potential hybrids between T. asiatica and T. saginata (Nkouawa et al ., 2009 ; Okamoto et al ., 2010 ; Yamane et al ., 2012 ; Ale et al ., 2014 ).…”

Bayesian Analysis of Three Methods for Diagnosis of Cystic Echinococcosis in Sheep

“…Fragmentation of parasite DNA may have affected our PCR-based methodology, preventing proper amplification of the 800 bp target. The design of different primers to shorten the amplicon length, thus reducing the likelihood of DNA polymerase to encounter template disruptions, would have possibly improved the diagnosis of hydatid cysts as reported for other cestode species [ 30 , 31 ].…”

High Prevalence of Bovine Cardiac Cysticercosis in Upper Egypt: An Epidemiological and Histopathological Study

“…Cattle serve as the intermediate host in the two-host life cycle, while humans represent the definitive hosts. Globally, around 50 million human cases were reported resulting in ~50 thousand fatalities annually [ 1 , 2 ]. Generally, humans get infected by consuming raw or undercooked meat containing infective cysticerci that develop into full grown tapeworms three months later.…”

“…Regarding the diagnosis of the infection, a visual examination of the cysticerci during the post-mortem examination of carcasses is typically employed for the detection of the parasites. Nevertheless, traditional methods have major drawbacks and limited diagnostic capability [ 1 , 11 ]. Moreover, standard inspection techniques are ineffective for detecting bovine cysticercosis at low concentrations.…”