RESUMO
Ascaris sp. is a soil-transmitted helminth (STH) significantly affecting the health of human and swine populations. Health inequities and poverty, with resulting deficiencies in water, sanitation and hygiene, are directly associated with Ascaris lumbricoides prevalence in humans. Resource constraints also lead to small-scale livestock production under unsanitary conditions. Free-ranging pigs, for instance, are exposed to a number of infectious agents, among which Ascaris suum is one of the most common. Under these conditions, close proximity between people and pigs can result in cross-contamination; that is, pigs harbouring human Ascaris and vice versa. Moreover, the potential interbreeding between these two Ascaris species has been demonstrated. The present study analysed Ascaris worms obtained from children and pigs in Honduras. Adult worms were collected from stool samples of children after pharmacological treatment, and from pigs' intestines after slaughter for commercial purposes at a local abattoir. A nuclear ribosomal internal transcribed spacer (ITS) region was amplified by polymerase chain reaction (PCR) and digested with a restriction enzyme in order to separate putative human- and pig-derived Ascaris isolates. PCR products were also sequenced, and cladograms were constructed. All parasites isolated from children showed the typical human-derived genotype of Ascaris, whereas 91% of parasites from pigs showed the expected pig-derived genotype. Cross-infections between hosts were not demonstrated in this study. Nine per cent of pig-derived worms showed a restriction band pattern highly suggestive of a hybrid human-pig Ascaris genotype. These results contribute to the understanding of ascariasis epidemiology and its zoonotic potential in a highly endemic region.
Assuntos
Ascaríase/epidemiologia , Ascaris/genética , DNA de Helmintos/genética , Genótipo , Doenças dos Suínos/epidemiologia , Animais , Ascaríase/transmissão , Ascaríase/veterinária , Ascaris/isolamento & purificação , Ascaris lumbricoides/genética , Ascaris lumbricoides/isolamento & purificação , Ascaris suum/genética , Ascaris suum/isolamento & purificação , Criança , DNA Espaçador Ribossômico/genética , Fezes/parasitologia , Honduras/epidemiologia , Humanos , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Suínos/parasitologia , Doenças dos Suínos/transmissão , Zoonoses/epidemiologia , Zoonoses/parasitologia , Zoonoses/transmissãoRESUMO
A two-phase study was conducted in a rural community in Honduras, to evaluate the association between neurocysticercosis (NCC) diagnosed by computed tomography (CT), epilepsy, seropositivity for antibodies to the cysticerci of Taenia solium [determined by enzyme-linked-immunoelectrotransfer-blot (EITB) assays], intestinal infection with this parasite, and various epidemiological factors. Of the 480 individuals studied in the first phase, 17% were seropositive and 2.5% supplied faecal samples which contained T. solium eggs. In the second phase, 148 individuals (74 of the seropositive subjects from the first phase and 74 matched controls from the seronegatives) underwent CT and neurological examinations. The CT results appeared normal in 110 (74%) of the 148, showed anatomical abnormality in seven (5%), and active or calcified lesions compatible with NCC in 31 (23% of the seropositives and 19% of the seronegatives). Only five of the latter had neurological symptoms (two being epileptics) and only five lived in households in which intestinal taeniasis had been detected. Subject age was significantly associated with NCC-compatible lesions but all the other factors investigated, including seropositivity, showed no significant association with the CT findings. The overall sensitivity of the EITB assays was found to be 55%. Taken together, the present results indicate that, even though it is a valuable tool in determining transmission levels in sero-epidemiological studies, the EITB assay should not be used to predict the existence of NCC or to estimate the prevalence of NCC. The results do provide further evidence that taeniasis and cysticercosis are widely prevalent in Honduras, and indicate that much larger studies of hyper-endemic communities may be necessary if the factors associated with the transmission of T. solium are to be elucidated.
Assuntos
Intestinos/parasitologia , Taenia , Teníase/diagnóstico , Teníase/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Anti-Helmínticos/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Cisticercose/diagnóstico , Cisticercose/epidemiologia , Ensaio de Imunoadsorção Enzimática/métodos , Fezes/parasitologia , Feminino , Honduras/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neurocisticercose/diagnóstico , Neurocisticercose/epidemiologia , Contagem de Ovos de Parasitas , Prevalência , Estudos Soroepidemiológicos , Tomografia Computadorizada por Raios XRESUMO
With the purpose of evaluating the available methodology for neurocysticercosis (NCC) diagnosis, 60 neurological patients were studied during a 4-year period in Honduras. Neurological evaluation, Computed Tomography (CT), cysticercosis Enzyme-Linked Immunoelectrotransfer blot (EITB) assay, electroencephalographic studies, and collection of epidemiological information were performed to assess a final diagnosis. The presenting clinical manifestations were: epileptic seizures (52%), headache without intracranial pressure (27%) and intracranial hypertension (10%). A protocol for the diagnosis of NCC is suggested. According to this protocol, patients with active (live) cysticercus and/or antibodies in Cerebrospinal fluid (CSF) were diagnosed as definitive cases of NCC, whereas those with only brain calcifications were diagnosed as probable cases. NCC diagnosis was definitive in 14 (23%) patients, probable in 32 (54%) and ruled out in 14 (23%). Of the patients with epileptic seizures, six (19%) had definitive and 20 (65%) had probable NCC. Overall seropositivity was 28%. EITB positivity varied from 14 to 100%, and from 20 to 35% in definitive and probable cases of NCC, respectively. When compared to CT, EITB overall sensitivity for definitive, active cases, was 50% in serum and 63% in CSF. These results suggest that brain images combined with neurological evaluation remains the best approach for neurocysticercosis diagnosis, and that EITB, even though its variable sensitivity, offers valuable information, especially if performed in CSF.
Assuntos
Doenças Endêmicas , Neurocisticercose/diagnóstico , Neurocisticercose/epidemiologia , Taenia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/líquido cefalorraquidiano , Criança , Pré-Escolar , Eletroencefalografia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Honduras/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neurocisticercose/parasitologia , Exame Neurológico , Taenia/imunologia , Taenia/isolamento & purificação , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: To identify exposure factors contributing to lead poisoning in school children from Mexico City. MATERIAL AND METHODS: Cross-sectional study of 340 children. A convenience sample of schools and a random sample of children were selected. A questionnaire was filled out and venous blood samples were taken. Lead levels were measured by atomic absorption spectrophotometry. Statistical analysis consisted of comparison of means using Student's t test and ANOVA. Multiple linear regression was used for multivariate analysis. Logarithmic transformation of lead blood levels were used to account for their non-normal distribution. RESULTS: Geometric means for private and public schools were: GM = 8.76 micrograms/dl, 95% CI = 9.1-10.5; GM = 11.5 micrograms/dl, 95% CI = 9.4-13.5. Lead levels were higher among children from public schools who are male, between 6 and 8 years of age, in first and second grade, whose mothers have a profession, who use glazed earthenware utensils, and who live near glazed earthenware shops or factories. CONCLUSIONS: Exposure predictors of lead blood levels are: being between 6 and 8 years of age, having a professional mother, using glazed earthenware utensils, living near glazed earthenware shops or factories, and studying the second grade of elementary school.
Assuntos
Exposição Ambiental , Chumbo/sangue , Criança , Estudos Transversais , Feminino , Humanos , Masculino , México , Análise de Regressão , Instituições Acadêmicas , Inquéritos e QuestionáriosRESUMO
Several retrospective studies have shown that human Taenia solium cysticercosis is endemic in Honduras, but very few reports of porcine cysticercosis in rural communities have been published. To determine the local prevalence of this disease in pigs, a serological survey has been undertaken in a rural community, Salamá, in the Department of Olancho in central Honduras. Eighty-five families raising pigs in the community were randomly selected and sera were obtained from pigs older than one month of age. The sera were examined by the enzyme-linked immunoelectrotransfer blot assay (EITB). Of 192 porcine sera, 27.1% (52) were positive by the EITB. Seropositivity did not correlate with age and sex by statistical analysis. With respect to the number and the frequency of recognition of the seven diagnostic glycoprotein bands in the EITB, 67.3% of the positive serum specimens recognized only one band and 80.8% of them recognized GP42-39. Since recognition of GP42-39 has been reported as a characteristic of late infection, these results suggest that most of the seropositive pigs were in the late stage of infection (more than 5-8 weeks postinfection). It seems that pigs in this community may be infected with this parasite soon after the birth and be in a hyperendemic steady state. In view of a high prevalence of antibodies to T. solium in pigs or characteristics of the antigen detected by the EITB, the infection pressure of T. solium appears to be very high in this community. This is probably the case in most of the communities in Honduras.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Cisticercose/veterinária , Cysticercus/imunologia , Gastroenteropatias/veterinária , Doenças dos Suínos/epidemiologia , Animais , Western Blotting/veterinária , Cisticercose/epidemiologia , Eletroforese/veterinária , Feminino , Gastroenteropatias/epidemiologia , Glicoproteínas/sangue , Glicoproteínas/imunologia , Honduras/epidemiologia , Masculino , Prevalência , Saúde da População Rural , SuínosRESUMO
To determine the prevalence of antibodies to Taenia solium and taeniasis in a population of urban residence, an epidemiological study was carried out in a military institution located in Tegucigalpa, the capital city of Honduras. A total of 404 persons were interviewed to collect epidemiological data, investigate antibodies to T. solium cysticercus by the enzyme-linked immunoelectrotransfer blot (EITB) assay and taeniasis by Ritchie's concentration technique. A total of 41 persons that were living at the headquarters and were traveling frequently to their rural hometowns were regarded as rural residents, the remaining 363 persons were considered urban residents. The seroprevalence of antibodies was 22% (9/41) in the rural residents and 15% (54/363) in the urban residents. The overall seroprevalence was 15.6% (63/404). Analyses of risk factors for seropositivity in the urban residents showed that seropositivity was statistically associated with poor household conditions such as raising pigs (odds ratio (OR), 5.39; 95% confidence interval (CI), 1.42-19.50), lack of potable water (OR, 3.66; CI, 1.25-9.94), lack of sanitary toilet (OR, 2.92; CI, 1.35-6.05) and earthen floor (OR, 2.48; CI, 1.28-4.73). Also seropositivity was associated with low academic education (OR, 2.5O; CI, 1.33-4.69) and lack of knowledge about the parasite (OR, 2.39; CI, 1.26-4.49). Out of 328 persons examined for intestinal parasites, two soldiers (0.6%) coming from rural areas were identified as Taenia sp. carriers. T. solium was identified in one case. Although T. solium infections originate and are more prevalent in rural villages, the high seroprevalence found in this study indicates that they can also be found at important levels in urban communities. Migration of tapeworm carriers from rural areas to the city grants the transmission of cysticercosis when poor environmental and social conditions are present.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Teníase/epidemiologia , Saúde da População Urbana/estatística & dados numéricos , Adolescente , Adulto , Idoso , Cisticercose/epidemiologia , Cisticercose/imunologia , Feminino , Honduras/epidemiologia , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Teníase/imunologiaRESUMO
An epidemiological study was conducted in a Honduran rural community in 1991, to determine the local prevalence and associated risk factors of Taenia infection. The seroprevalence of anti-cysticercus antibodies, investigated by ELISA (N = 526), was found to be 30%. The prevalence of intestinal infections with Taenia and other parasites was investigated, by formol-ether concentration of three stool samples from each subject (N = 536). Almost all (96%) of the subjects carried at least one of the 17 species of intestinal parasite identified, 11 (2%) of them (nine of them female) being found to be infected with Taenia spp. When nine of these 11 were given niclosamide, four expelled Taenia segments, all of which were identified as T. solium after carmine staining. Risk factors associated with seropositivity were earthen floor, overcrowding, previous taeniasis and living in the same household as a person reporting previous taeniasis. Four years later (1995), a follow-up study in a sub-sample of the previously studied population revealed that 34% of the subjects were seropositive for anti-Taenia solium antibodies (as determined by a cysticercosis-specific, enzyme-linked, immunoelectrotransfer, blot assay) and that 1.5% had taeniasis. Taeniasis and cysticercosis therefore appear to be important public-health problems in rural areas of Honduras, as they are in other countries of Latin America. Large-scale studies need to be conducted to facilitate the design of programmes to control these diseases.
Assuntos
Teníase/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Criança , Pré-Escolar , Fezes/parasitologia , Feminino , Seguimentos , Cefaleia/complicações , Helmintos/classificação , Helmintos/isolamento & purificação , Honduras/epidemiologia , Humanos , Imunoensaio , Lactente , Masculino , Valor Preditivo dos Testes , Gravidez , Prevalência , Fatores de Risco , Convulsões/complicações , Sensibilidade e Especificidade , Teníase/complicações , Teníase/imunologiaRESUMO
Epidemiological and health system research projects are often delayed due to the difficulties to build validated data basis in personal computers. This papers presents a new computer interactive program for handling numeric data from a given questionnaire to a structured archive. The questionnaire includes the basic variables of the dwelling and of the members of the household. A list of sociodemographic and health variables are selected, although other variables can be easily added, according to special needs. All the intermediate steps regularly needed to construct a data base are included in the package: capture, verification, validation and record linkage. The package is equipped with the basic procedures needed to produce tabulations and basic statistical analysis.