RESUMO
Taenia solium cysticerci are a major cause of human seizures and epilepsy in the world. In the gastrointestinal tract of infected individuals, taeniid eggs release the oncospheres, which are then activated by intestinal stimuli, getting ready to penetrate the gut wall and reach distant locations where they transform in cysticerci. Information about oncospheral molecules is scarce, and elucidation of the oncosphere proteome could help understanding the host-parasite relationship during the first steps of infection. In this study, using liquid chromatography and tandem mass spectrometry (LC-MS/MS) analysis, we could identify a set of oncospheral proteins involved in adhesion, protein folding, detoxification and proteolysis, among others. In addition, we have characterized one of the identified molecules, the parasite 14-3-3, by immunoblot and immunolocalization. The identification of these oncospheral proteins represents the first step to elucidate their specific roles in the biology of the host-parasite relationship.
Assuntos
Proteínas de Helminto/análise , Proteoma/análise , Proteômica , Taenia solium/química , Animais , Western Blotting , Cromatografia Líquida , Espectrometria de Massas em TandemRESUMO
A combined (human and porcine) mass chemotherapy program was tested in a controlled design in 12 village hamlets in the Peruvian highlands. A single dose of 5 mg of praziquantel was given to eliminate intestinal taeniasis in humans, and two rounds of oxfendazole (30 mg/kg) were administered to all pigs. The total population in the study villages was 5,658 resident individuals, and the porcine population at the beginning of the study was 716 pigs. Human treatment coverage was 75%, ranging from 69% to 80%. There were only a few refusals of owners for porcine treatment of their animals. The effect of the intervention was measured by comparing incidence rates (seroconversion in pigs who were seronegative 4 months before) in treatment versus control villages, before and up to 18 months after treatment. There was a clear effect in decreasing prevalence (odds ratio, 0.51; P < 0.001) and incidence (odds ratio, 0.39; P < 0.013) in the treatment area after the intervention, which did not leave to extinction of the parasite but stabilized in slightly decreased rates persisting along the follow-up period. Mass chemotherapy was effective in decreasing infection pressure in this hyperendemic area. However, the magnitude of the effect was small and did not attain the goal of eliminating transmission.
Assuntos
Anticestoides/administração & dosagem , Benzimidazóis/administração & dosagem , Praziquantel/administração & dosagem , Teníase/epidemiologia , Teníase/prevenção & controle , Adolescente , Adulto , Animais , Criança , Feminino , Humanos , Incidência , Masculino , Peru/epidemiologia , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle , Taenia solium , Teníase/sangue , Teníase/tratamento farmacológicoRESUMO
An epidemiological study was conducted in a highland, rural community in Peru, to determine the seroprevalences of human and porcine infection with Taenia solium and the risk factors associated with human infection. The seroprevalences, determined using an assay based on enzyme-linked-immuno-electrotransfer blots (EITB), were 21% (66/316) in the humans and 65% (32/49) in the pigs. The human subjects aged <30 years were more likely to be positive for anti-T. solium antibodies than the older subjects (P < 0.001). The risk factors associated with human seropositivity were lack of education beyond the elementary level [odds ratio (OR)=2.69; 95% confidence interval (CI)=1.09-6.65] and pig-raising (OR=1.68; CI=0.96-2.92). Curiously, sheep-raising was inversely associated with human T. solium infection (OR=0.50; CI=0.28-0.90). The study site appears to be a new endemic focus for T. solium in the central Peruvian Andes. Although, in earlier studies, the seroprevalence of T. solium infection has generally been found to increase with age, the opposite trend was observed in the present study. The results of follow-up studies should help determine if the relatively high seroprevalence in the young subjects of the present study is the result of a transient antibody response.
Assuntos
Saúde da População Rural , Teníase/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Anti-Helmínticos/análise , Criança , Pré-Escolar , Feminino , Humanos , Immunoblotting/métodos , Lactente , Masculino , Pessoa de Meia-Idade , Peru/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/epidemiologia , Taenia solium/imunologia , Teníase/imunologia , Teníase/veterináriaRESUMO
We performed repeated serological sampling of pigs in an endemic area of the Peruvian highlands (eight villages) to assess the feasibility of detecting incident cases of Taenia solium infection as indicators of ongoing transmission of the parasite. A total of 2245 samples corresponding to 1548 pigs were collected in three sampling rounds (n=716, 926, and 603, respectively). Village-period specific seroprevalences of antibodies by enzyme-linked immunoelectrotransfer blot (EITB) assay varied from 39% (95% CI: 34, 44) to 76% (95% CI: 72, 79). The prevalence of cysticercosis increased with the age of the pigs (similarly for both sexes). Around 40% of pigs were re-sampled at the end of each 4-month period. Crude incidence risks were 48% (57/120, 95% CI: 43-52) and 58% (111/192, 95% CI: 54-61) for each period. A proportion of seropositive animals became seronegative at the end of each period (23 and 15%). Incidence varied by the village, and the exposure period, and was higher in males than females (but did not differ by age).
Assuntos
Anticorpos Anti-Helmínticos/sangue , Doenças dos Suínos/epidemiologia , Taenia solium/imunologia , Teníase/veterinária , Fatores Etários , Animais , Feminino , Incidência , Masculino , Peru/epidemiologia , Estudos Soroepidemiológicos , Fatores Sexuais , Suínos , Doenças dos Suínos/parasitologia , Doenças dos Suínos/transmissão , Taenia solium/patogenicidade , Teníase/epidemiologia , Teníase/transmissãoRESUMO
Cysticercosis, the infection by the larvae of Taenia solium, is a major cause of acquired epilepsy in the world; it also causes significant economic loss because of contaminated pork. This disease is endemic in most developing countries and no control strategy has yet been proven efficient and sustainable. To further evaluate the full potential of single-dose oxfendazole treatment for pigs as a control measure, 20 pigs with cysticercosis were treated with oxfendazole and later matched with 41 naive pigs and exposed to a natural challenge in a hyperendemic area. New infections were found by serologic testing in 15 of the 32 controls (47%), and by the presence of cysts at necropsy in 12 of them (37%). Only minute residual scars were detected in the carcasses of oxfendazole-treated pigs. Pigs with cysticercosis, once treated with oxfendazole, are protected from new infections for at least three months.
Assuntos
Anti-Helmínticos/uso terapêutico , Benzimidazóis/uso terapêutico , Cisticercose/veterinária , Doenças dos Suínos/prevenção & controle , Taenia/efeitos dos fármacos , Animais , Anticorpos Anti-Helmínticos/sangue , Encéfalo/parasitologia , Cisticercose/epidemiologia , Cisticercose/prevenção & controle , Immunoblotting/veterinária , Estudos Prospectivos , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/tratamento farmacológico , Doenças dos Suínos/parasitologiaRESUMO
The discordance between extremely high seroprevalence of Taenia solium antibodies in disease-endemic populations, relatively few symptomatic cases of neurocysticercosis, and high background levels of putatively inactive brain lesions (mainly calcifications) in seronegative controls have confused researchers, clinicians, and epidemiologists in the last decade. We reviewed longitudinal serologic data from general population serosurveys in 3 different disease-endemic areas of Peru and Colombia and found that approximately 40% of seropositive people were seronegative when resampled after 1 year (3 surveys) or after 3 years (1 survey). Transient antibodies may have significant implications for the epidemiology of and immunity to this disease.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/epidemiologia , Cisticercose/imunologia , Taenia/imunologia , Animais , Anticorpos Anti-Helmínticos/biossíntese , Antígenos de Helmintos/sangue , Colômbia/epidemiologia , Humanos , Immunoblotting , Estudos Longitudinais , Peru/epidemiologia , Estudos SoroepidemiológicosRESUMO
A novel method for infecting pigs with Taenia solium using an intramuscular innoculum of oncospheres was investigated in a series of five experiments in 18 animals. The model is simple to perform, requires a minimal number of oncospheres, permits multiple infections per animal, and decreases the variation inherent in oral infection models. This intramuscular oncosphere assay (IMOA) may provide a valuable tool to evaluate therapeutic agents or potential vaccines for cysticercosis.
Assuntos
Cisticercose/veterinária , Cysticercus/patogenicidade , Modelos Animais de Doenças , Doenças dos Suínos/parasitologia , Administração Oral , Animais , Cisticercose/parasitologia , Histocitoquímica , Injeções Intramusculares/veterinária , Injeções Intraperitoneais/veterinária , Injeções Intravenosas/veterinária , SuínosRESUMO
An investigation was performed after an outbreak of bartonellosis in a region of Peru nonendemic for this disorder. Symptoms of acute and chronic bartonellosis were recorded. Serological analysis was performed on 55% of the affected population (554 individuals), 77.5% of whom demonstrated previous infection with Bartonella bacilliformis. The attack rate of Oroya fever was 13.8% (123 cases); the case-fatality rate was 0.7%. The attack rate of verruga peruana was 17.6%. A new specific immunostain was developed and used to confirm the presence of B. bacilliformis in the biopsied skin lesions. Most seropositive individuals (56%) were asymptomatic. The symptoms that were associated with prior infection, as determined by Western blot, included fever (37.2% of the seropositive vs. 17.2% of the seronegative population; P<.001), bone and joint pain (27% vs. 9%; P<.001), headache (27% vs. 12.3%; P <.001), and skin lesions described as verruga peruana (26.8% vs. 4.9%; P<.001). Our findings suggest that infection with B. bacilliformis causes a broad spectrum of disease that is significantly milder in severity than that frequently reported.
Assuntos
Infecções por Bartonella/epidemiologia , Adolescente , Adulto , Animais , Bartonella , Infecções por Bartonella/patologia , Criança , Escolaridade , Feminino , Humanos , Umidade , Masculino , Peru/epidemiologia , Coelhos , Pele/patologia , TemperaturaRESUMO
Species-specific identification of human tapeworm infections is important for public health purposes, because prompt identification of Taenia solium carriers may prevent further human cysticercosis infections (a major cause of acquired epilepsy). Two practical methods for the differentiation of cestode proglottids, (i) routine embedding, sectioning, and hematoxylin-eosin (HE) staining and (ii) PCR with restriction enzyme analysis (PCR-REA), were tested on samples from 40 individuals infected with T. solium (n = 34) or Taenia saginata (n = 6). Microscopic examination of HE staining of sections from 24 cases, in which conserved proglottids were recovered, clearly revealed differences in the number of uterine branches. Distinct restriction patterns for T. solium and T. saginata were observed when the PCR products containing the ribosomal 5.8S gene plus internal transcribed spacer regions were digested with either AluI, DdeI, or MboI. Both HE histology and PCR-REA are useful techniques for differentiating T. solium from T. saginata. Importantly, both techniques can be used in zones of endemicity. HE histology is inexpensive and is currently available in most regions of endemicity, and PCR-REA can be performed in most hospital centers already performing PCR without additional equipment or the use of radioactive material.
Assuntos
Taenia/classificação , Teníase/parasitologia , Animais , DNA Ribossômico/genética , Amarelo de Eosina-(YS) , Hematoxilina , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Proibitinas , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/genética , Coloração e Rotulagem , Taenia/anatomia & histologia , Taenia/genéticaRESUMO
To document the natural history of Echinococcus granulosus infection and response to treatment of human hydatidosis, we reexamined 28 of 37 subjects with E. granulosus infection diagnosed in an epidemiological study conducted in 1994. Twenty-six (70%) of those 37 subjects underwent abdominal ultrasonography, chest radiography, and enzyme-linked immunoelectrotransfer blot assay in 1997. Medical records from two additional individuals were reviewed. Eight patients had their cysts surgically removed during the 3-year follow-up interval; no surgical complications or recurrences occurred. Among eight patients with cystic disease not treated by surgery, four had cyst-growth ranging from 0.4 to 1.4 cm during the 3-year interval. One patient developed a new cyst and another's simple cyst became septate; two developed new calcifications. Of 12 seropositive subjects with no cysts present in 1994, 10 reverted to seronegative, a finding that suggests a significant proportion of seropositive subjects in echinococcus-endemic regions may have only transient infection without disease. When cysts do develop, their growth rates and time courses are highly variable; over the 3-year period, we observed growth, septation, degeneration, and calcification of cysts.