RESUMO
Taenia solium is the most common parasite infection of the brain, causing neurocysticercosis and typically found in rural communities with free-ranging pigs. Identification of transmission in rural areas is essential for its control. Risk factors and transmission of the parasite were evaluated in three rural Venezuelan communities (Valle del Rio and Potrero Largo, Cojedes state; and Palmarito, Portuguesa state) by a questionnaire (112 households) and coprological (492 samples) and serological (433 human and 230 porcine sera) analysis, respectively. Typical risk factors were found in all three communities: free-foraging pig husbandry, deficient sanitary conditions, high open defecation and ignorance of the parasite life cycle. Coprological examinations revealed a high level of soil-transmitted parasites. Importantly, two T. solium adult worm carriers were identified in each of the three communities. Anti-metacestode antibodies and the HP10 secreted metacestode glycoprotein were detected at significant levels in human and porcine sera in Valle del Rio, Potrero Largo and Palmarito. In conclusion, these communities may be considered to be endemic for taeniasis/cysticercosis, and the instigation of an appropriate control programme is recommended.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/epidemiologia , População Rural , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/parasitologia , Teníase/epidemiologia , Adulto , Animais , Antígenos de Helmintos/análise , Cisticercose/imunologia , Características da Família , Fezes/parasitologia , Humanos , Fatores de Risco , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/imunologia , Taenia solium/imunologia , Teníase/imunologia , VenezuelaRESUMO
The aim of this study was to assess transmission of Taenia solium cysticercosis in Palmarito Arriba, a small village in the rural area of the Portuguesa state of Venezuela, through (1) an evaluation of T. solium transmission risk factors present in the community and (2) serological detection of the secreted metacestode HP10 antigen (HP10 Ag) and of anti-metacestode antibodies in sera from rural pigs. Risk factors associated with transmission of cysticercosis were the following: 100% (23/23) of the households lacked piped water, 87.0% (20/23) of households lacked latrines, 88.0% (100/114) of inhabitants routinely defecated in the open/air, 19.05% (12/63) of the interviewed population had observed proglottids in their stools. More significantly, 9/13 householders breeding pigs reported seeing proglottids in their stools. Of the 25 pigs available for bleeding and serological testing, 64% (16/25) were free roaming and 36% (9/25) were "backyard" animals; 28% (7/25) were seropositive for both the HP10 Ag and antibody, 20.0% (5/25) were seropositive for HP10 Ag alone, and 36.0% (9/25) were seropositive for antibody alone. Given this clear evidence of endemic porcine cysticercosis, further studies are needed to assess and control the level of porcine and human taeniasis and cysticercosis in this and neighboring communities.
Assuntos
Cisticercose/veterinária , Doenças dos Suínos/epidemiologia , Taenia solium/fisiologia , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/sangue , Cisticercose/epidemiologia , Cisticercose/parasitologia , Cisticercose/transmissão , Feminino , Masculino , Fatores de Risco , Estudos Soroepidemiológicos , Sus scrofa , Suínos , Doenças dos Suínos/parasitologia , Doenças dos Suínos/transmissão , Venezuela/epidemiologiaRESUMO
Parasitic diseases of the central nervous system are associated with high mortality and morbidity, especially in resource-limited settings. The burden of these diseases is amplified as survivors are often left with neurologic sequelae affecting mobility, sensory organs, and cognitive functions, as well as seizures/epilepsy. These diseases inflict suffering by causing lifelong disabilities, reducing economic productivity, and causing social stigma. The complexity of parasitic life cycles and geographic specificities, as well as overlapping clinical manifestations in the host reflecting the diverse pathogenesis of parasites, can present diagnostic challenges. We herein provide an overview of these parasitic diseases and summarize clinical aspects, diagnosis, therapeutic strategies and recent milestones, and aspects related to prevention and control.
Assuntos
Pessoal Administrativo , Infecções Parasitárias do Sistema Nervoso Central/diagnóstico , Infecções Parasitárias do Sistema Nervoso Central/terapia , Gerenciamento Clínico , Pessoal Administrativo/psicologia , Antiparasitários , Infecções Parasitárias do Sistema Nervoso Central/complicações , Infecções Parasitárias do Sistema Nervoso Central/epidemiologia , HumanosRESUMO
Human neurocysticercosis (NC) is caused by Taenia solium larvae lodged in the central nervous system. This disease is usually diagnosed by radiology but the results are not always clear-cut and so immunological assays are often also used. A semi-nested PCR, based on the non-coding HDP2 sequence of T. saginata, has now been developed for detecting DNA from T. solium cysticerci and confirming NC. This PCR, which amplifies a 171-bp T. solium product, allowed the specific detection of just 174 attograms of T. solium DNA. The efficacy of the PCR was tested using cerebrospinal fluid (CSF) from neurological patients, including 46 confirmed Mexican cases of NC and 32 patients from non-endemic Spain. Eighteen of the confirmed cases [including 10 (71%) of the 14 with vesicular extraparenchymal cysticerci and four (17%) of the 24 with damaged cysticerci] and two (33%) of the six patients with 'uncertain' diagnosis (in whom a diagnosis of NC could not be established by radiological and immunological studies) were found PCR-positive. The 36 patients known to have neurological problems other than NC were found PCR-negative. The HDP2 PCR offers a new tool in the diagnosis of NC and in exploring the pathogenesis of this serious disease.
Assuntos
Anticorpos Anti-Helmínticos/líquido cefalorraquidiano , Antígenos de Helmintos/líquido cefalorraquidiano , DNA de Helmintos/líquido cefalorraquidiano , Neurocisticercose/líquido cefalorraquidiano , Taenia solium/genética , Animais , Feminino , Humanos , Masculino , Neurocisticercose/diagnóstico , Reação em Cadeia da Polimerase/métodos , Sensibilidade e EspecificidadeRESUMO
With the aim of genotyping Echinococcus granulosus cysts found in Mexican livestock, we collected hydatid cysts from the livers and lungs of pigs in slaughterhouses in the state of Morelos, Central Region of Mexico. DNA was extracted from the parasites and examined by polymerase chain reaction (PCR) of rDNA internal transcribed spacer 1 (ITS1-PCR), Eg9-PCR, Eg16-PCR, and PCR-restriction fragment length polymorphism (PCR-RFLP). In addition, fragments of the genes coding for mitochondrial cytochrome c oxidase subunit 1 (CO1) and NADH dehydrogenase 1 (ND1) were sequenced. Two different genotypes of E. granulosus were unequivocally identified, the common sheep genotype, G1, and the common pig genotype, G7. The G1 genotype of E. granulosus has not been previously demonstrated in Mexico. Because of its recognized infectivity in humans, G1 genotype is a direct threat to human health and its presence in Mexico is consequently of immediate public health importance and epidemiological relevance.
Assuntos
Equinococose Hepática/veterinária , Equinococose Pulmonar/veterinária , Echinococcus granulosus/genética , Doenças dos Suínos/parasitologia , Animais , Equinococose Hepática/parasitologia , Equinococose Pulmonar/parasitologia , Echinococcus granulosus/isolamento & purificação , Genes de Protozoários/genética , Genótipo , Fígado/parasitologia , Pulmão/parasitologia , México , SuínosRESUMO
This study examined the seroprevalence and serum antibody isotype profile for Taenia solium cysticercosis in an Amerindian community in the Amazonas state of Venezuela. An antigen-trapping enzyme-linked immunosorbent assay (Ag-ELISA) was used to detect viable cysticercosis. Indirect ELISA (Ab-ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) was performed by using antigens prepared from T. solium metacestodes to detect anti-parasite antibodies. The Ag-ELISA and Ab-ELISAs revealed 64.7% and 79.0% seropositivity, respectively, in the Amerindian population. Immunoglobulin (Ig) M was the predominant antibody class, suggesting recent infection. In comparison sera from, clinically defined, hospital neurocysticercosis cases revealed only 27% seropositivity by Ag-ELISA, compared with 86-92% seropositivity by Ab-ELISA, and IgG4 was the predominant antibody subclass detected. The EITB antigen recognition patterns of the hospitalized patients were very similar to that of the Amerindians, confirming exposure to the parasite. These results, combined with the predominance of IgM antibody responses and the marked detection of secreted products of viable parasites, strongly suggest that recent exposure to T. solium had occurred in the Amerindian population.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/epidemiologia , Taenia/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Cisticercose/etiologia , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Immunoblotting , Indígenas Sul-Americanos , Masculino , Neurocisticercose/epidemiologia , Neurocisticercose/etiologia , Estudos Soroepidemiológicos , Taenia/isolamento & purificação , Venezuela/epidemiologiaRESUMO
Eosinophils have long been thought to be effectors of immunity to helminth but have also been implicated in the pathogenesis of asthma. Patterns of cytokine production in the host may influence the pathogenesis of these diseases by regulating the activities of eosinophils and other components of the immune response. Mice which constitutively over-express IL-5 have profound and life-long eosinophilia in a restricted number of tissues. Although eosinophils from IL-5 transgenics are funtionally competent for a number of parameters considered to be important in inflammation, untreated animals are overtly normal and free of disease. In addition, the responses of these animals when exposed to aeroallergens and helminth present a number of apparent paradoxes. Eosinophil accumulation in tissue adjacent to major airways is rapid and extensive in transgenics exposed to the aeroallergen, but even after treatment with antigen over many months these mice show no evidence of respiratory distress or pathology. Helminth-infected IL-5 transgenics and their non-transgenic littermates develop similar inflammatory responses at mucosal sites and are comparable for a number of T cell and antibody responses, but they differ considerably in their ability to clear some parasite species. The life-cycle of Nippostrongylus brasilensis is significantly inhibited in IL-5 transgenics, but that of Toxocara canis is not. Our results suggest that eosinophilia and/or over-expression of IL-5 may actually impair host resistance to Schistosoma mansoni and Trichinella spiralis. The pathogenesis of diseases in which eosinophils are involved may therefore be more complex than previously thought.