Dataset Information

Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.

ABSTRACT:

Background

Taenia solium inflicts substantial neurologic disease and economic losses on rural communities in many developing nations. "Ring-strategy" is a control intervention that targets treatment of humans and pigs among clusters of households (rings) that surround pigs heavily infected with cysticerci. These pigs are typically identified by examining the animal's tongue for cysts. However, as prevalence decreases in intervened communities, more sensitive methods may be needed to identify these animals and to maintain control pressure. The purpose of this study was to evaluate ultrasonography as an alternative method to detect pigs heavily infected with T. solium cysts.

Methodology/principal findings

We purchased 152 pigs representing all seropositive animals villagers were willing to sell from eight communities (pop. 2085) in Piura, Peru, where T. solium is endemic. Tongue and ultrasound examinations of the fore and hind-limbs were performed in these animals, followed by necropsy with fine dissection as gold standard to determine cyst burden. We compared the sensitivity and specificity of ultrasonography with tongue examination for their ability to detect heavy infection (? 100 viable cysts) in pigs. Compared to tongue examination, ultrasonography was more sensitive (100% vs. 91%) but less specific (90% vs. 98%), although these differences were not statistically significant. The greater sensitivity of ultrasound resulted in detection of one additional heavily infected pig compared to tongue examination (11/11 vs. 10/11), but resulted in more false positives (14/141 vs. 3/141) due to poor specificity.

Conclusions/significance

Ultrasonography was highly sensitive in detecting heavily infected pigs and may identify more rings for screening or treatment compared to tongue examination. However, the high false positive rate using ultrasound would result in substantial unnecessary treatment. If specificity can be improved with greater operator experience, ultrasonography may benefit ring interventions where control efforts have stalled due to inadequate sensitivity of tongue examination.

SUBMITTER: Flecker RH

PROVIDER: S-EPMC5242540 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Publications

Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.

Flecker Robert H RH Pray Ian W IW Santivaňez Saul J SJ Ayvar Viterbo V Gamboa Ricardo R Muro Claudio C Moyano Luz Maria LM Benavides Victor V Garcia Hector H HH O'Neal Seth E SE

PLoS neglected tropical diseases 20170105 1

<h4>Background</h4>Taenia solium inflicts substantial neurologic disease and economic losses on rural communities in many developing nations. "Ring-strategy" is a control intervention that targets treatment of humans and pigs among clusters of households (rings) that surround pigs heavily infected with cysticerci. These pigs are typically identified by examining the animal's tongue for cysts. However, as prevalence decreases in intervened communities, more sensitive methods may be needed to iden ...[more]

PMID: 28056028

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Project description:Traumatic pericarditis (TP) remains a serious problem facing bovine producers; particularly in the developing countries; causing severe economic losses. This study was carried out on 47 buffaloes including; control buffaloes (n = 20) and buffaloes with TP (n = 27) at Assiut governorate, Egypt. All animals were subjected to thorough clinical examination, whole blood profiling, blood serum biochemical assays, and radiographic and ultrasonographic examinations. The recorded ultrasonographic findings included; the contractility, contour and shape of the reticulum, shape and size of the heart and spleen involvement. All data were statistically analysed. Buffaloes with TP showed lymphocytic leucocytosis, increase in serum activities of AST, hyperproteinaemia, hypoalbuminaemia and hyperglobulinaemia. Radio-opaque metal foreign bodies, cardiomegaly and loss of the normal cardiac shape and contour were the most common radiographic findings in the diseased buffaloes. Ultrasonographically, the diseased buffaloes showed either acute pericarditis (n = 10) or chronic suppurative pericarditis (n = 17). Complete cessation of reticular contractions (0/3 min) and displacement of the reticulum from the diaphragm by a distance about 2.6-4.5 cm were the most common ultrasonographic findings of both types of pericarditis. In addition, the reticulum had uneven contour and the heart showed characteristic changes in its size, shape and contractility that was either accelerated or reduced. Reticular abscesses and peritoneal effusions were also imaged in all diseased buffaloes. In acute TP; the affected heart was enlarged with strong and clear cardiac contractions. Accumulation of hypoechoic fluids interspersed with echogenic deposits of fibrin within heart tissue and pericardium was observed. In chronic suppurative pericarditis, cardiomegaly, thickening of the cardiac wall and loss of the characteristic recognisable heart shape were the common ultrasonographic findings. Accumulation of hypoechoic fluids (usually pus) interspersing with echogenic deposits of fibrin within the pericardium, ventricles, atria and valves was also observed. In conclusion, ultrasonography with the aids of other diagnostic tools such as clinical findings, laboratory analysis and radiography has a high efficacy in evaluation of diseased buffaloes with TP.

Project description:Taenia solium is an important cause of acquired epilepsy worldwide and remains endemic in Asia, Africa, and Latin America. Transmission of this parasite is still poorly understood despite the design of infection experiments to improve our knowledge of the disease, with estimates for critical epidemiological parameters, such as the probability of human-to-pig infection after exposure to eggs, still lacking. In this paper, a systematic review was carried out and eight pig infection experiments were analyzed to describe the probability of developing cysts. These experiments included different pathways of inoculation: with ingestion of proglottids, eggs, and beetles that ingested eggs, and direct injection of activated oncospheres into the carotid artery. In these experiments, different infective doses were used, and the numbers of viable and degenerated cysts in the body and brain of each pig were registered. Five alternative dose-response models (exponential, logistic, log-logistic, and exact and approximate beta-Poisson) were assessed for their accuracy in describing the observed probabilities of cyst development as a function of the inoculation dose. Dose-response models were developed separately for the presence of three types of cysts (any, viable only, and cysts in the brain) and considered for each of the four inoculation methods ("Proglottids", "Eggs", "Beetles" and "Carotid"). The exact beta-Poisson model best fit the data for the three types of cysts and all relevant exposure pathways. However, observations for some exposure pathways were too scarce to reliably define a dose-response curve with any model. A wide enough range of doses and sufficient sample sizes was only found for the "Eggs" pathway and a merged "Oral" pathway combining the "Proglottids", "Eggs" and "Beetles" pathways. Estimated parameter values from this model suggest that a low infective dose is sufficient to result in a 50% probability for the development of any cyst or for viable cyst infections. Although this is a preliminary model reliant on a limited dataset, the parameters described in this manuscript should contribute to the design of future experimental infections related to T. solium transmission, as well as the parameterization of simulation models of transmission aimed at informing control.

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Project description:Taenia solium cysticercosis is the most common cause of acquired epilepsy in pig-raising and pork-consuming parts of Africa, Latin America, and Asia. This review aimed to systematically compile and synthesize data on the epidemiology of porcine cysticercosis in the Eastern and Southern Africa (ESA) region. Comprehensive searching strategies were employed to retrieve the studies published or reported between January 1,1997 and March 1, 2021, from Pub Med, Hinari, and Google Scholar databases and search platforms. The identified studies that met the inclusion criteria were then appraised for methodological quality. Finally, 44 studies obtained from nine countries were selected and included in this review. Relevant data were extracted using standardized templates for qualitative synthesis and meta-analysis. The overall pooled prevalence estimate of porcine cysticercosis in the ESA region was 17% (95% CI: 14-20%). The prevalence level between and within countries showed high variability. The pooled estimate showed high heterogeneity among the reports (the inverse variance index value (I2) of 98.99%, p < 0.05). The meta-analysis sub-grouped by the type of diagnostic test showed the pooled prevalence estimate of 27% (95% CI: 9-50) by carcass dissection; 23% (95% CI: 14-33) by Antibody-based immunodiagnostic techniques; 23% (95% CI: 18-29) by antigen detecting (Ag)-ELISA, 12% (95% CI: 7-18) by meat inspection, and 9% (95% CI: 7-11) by lingual examination. The meta-analysis sub-grouped by region showed a relatively higher pooled prevalence estimate for the Southern region 22% (95% CI: 15-30) compared to 13% (95% CI: 11-15) in the Eastern region. The highest country-based pooled prevalence was obtained from South Africa (33%, 95% CI: 20-48) and Zambia (22%, 95% CI: 16-29), whereas the lowest pooled prevalence was identified in Madagascar (5%, 95% CI: 4-5) and Rwanda (7%, 95% CI: 6-8). The lack of latrine, traditional pig husbandry practices, unprotected water sources, and increase in age were identified as significant risk factors for the occurrence of porcine cysticercosis in the pooled studies. The findings of this review will provide context-specific input to prioritize the possible intervention programs for T. solium control in the ESA region. More sensitive and specific test-based prevalence estimates, detailed risk factor investigations, and financial losses analysis are needed to establish feasible control strategies.Systematic review registrationhttp://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021238931.

Dataset Information

Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.

Background

Methodology/principal findings

Conclusions/significance

Publications

Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.

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