An objective reconstruction of the chain of contagion.

North's clustering method, which is based on a much used ecological model, the nearest neighbor distance, was applied to the objective reconstruction of the chain of household-to-household transmission of variola minor (the mild form of smallpox). The discrete within-household outbreaks were considered as points which were ordered in a time sequence using a 10-40 day interval between introduction of the disease into a source household and a receptor household. The closer points in the plane were assumed to have a larger probability of being links of a chain of household-to-household spread of the disease. The five defining distances (Manhattan or city-block distance between presumptive source and receptor dwellings) were 100, 200, 300, 400 and 500 m. The subchain sets obtained with the five defining distances were compared with the subchains empirically reconstructed during the field study of the epidemic through direct investigation of personal contacts of the introductory cases with either introductory or subsequent cases from previously affected households. The criteria of fit of theoretical to empirical clusters were: (a) the number of clustered dwellings and of subchains , (b) number of dwellings in a subchain and (c) position of dwellings in a subchain . The defining distance closest to the empirical findings was 200 m, which fully agrees with the travelling habits of the study population. Less close but acceptable approximations were obtained with 100, 300, 400 and 500 m. The latter two distances gave identical results, as if a clustering ceiling had been reached. It seems that North's clustering model may be used for an objective reconstruction of the chain of contagious whose links are discrete within-household outbreaks.

[The positivity index of the immunoenzyme reaction (ELISA) for cysticercosis in the cerebrospinal fluid (CSF) and in the serum of epilepsy patients]. / Indice de positividade da reação imunoenzimática (ELISA) para cisticercose no líquido cefalorraquidiano (LCR) e no soro de pacientes com epilepsia.

Fifty patients with epilepsy seen in three Londrina Neurological Services, in Paraná, were studied. The positivity prevalence of the enzyme-linked immunosorbent assay (ELISA) for cysticercosis in the cerebrospinal fluid (CSF) and in the serum of these patients was 34.0% and 20.0%, respectively. There was statistically significant difference when these two rates were compared with the reaction positivity in the CSF and the serum in the control group, formed by individuals without neurological diseases. There was no association between the type of seizure (generalized or partial) and the positivity index of ELISA for cysticercosis in the CSF. A greater number of patients with positive ELISA for cysticercosis in the rural area dwellers was found, in relation with the urban area dwellers. From the obtained results in our study we came to the following conclusions: 1. The high positivity ELISA rates for cysticercosis in the CSF and in the patients serum with epilepsy indicate that neurocysticercosis is an important seizure cause in Londrina, PR. 2. The positivity prevalence of ELISA for cysticercosis in CSF was greater in epileptic patients from the rural area than the ones from the urban area. 3. There was no association between the type seizure (generalized or partial) and the ELISA cysticercosis positivity rate in the CSF. 4. The high positivity prevalence of ELISA in the CSF and in the epileptic patients serum in Londrina indicates the priority of performing epidemiologic inquiry to establish the real cysticercosis prevalence in the city. ELISA may be used with this finality due to its high sensibility, its low cost and its simple performance.

[Treatment of experimental infection by Strongyloides venezuelensis in rats, with the use of injectable ivermectin and levamisole]. / Tratamento da infecção experimental de ratos por Strongyloides venezuelensis, mediante uso da ivermectina e do levamisol injectáveis.

For the therapy of human strongyloidiasis, are necessary effective drugs to eliminate both larvae and adult worm parasitism, which may also be used by parenteral route, to obviate the particular conditions presented by many patients. A study based on the experimental infection by Strongyloides venezuelensis in rats was done, administering injectable ivermectin or levamisole. Both drugs were shown to be active, when used in single doses of 0.2 to 0.5 mg/kg of ivermectin, or 26 mg/kg for levamisole. Ivermectin was slightly more effective as far as larval stage of the infection is concerned, and the same happened for levamisole for the adult worm stage. Promising perspectives are visualized to improve the therapy of patients with serious disseminated infection by Strongyloides stercoralis.

[Attempts to culturing triatominae in the laboratory using "in vitro" feeding]. / Tentativas de criação de triatomíneos em laboratório por meio de alimentação "in vitro".

In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a) analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b) assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evident that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior.

[Xenodiagnosis in Chagas disease: influence of the triatominae sex]. / O xenodiagnóstico na doença de chagas: influência do sexo dos triatomíneos.

We evaluated, comparatively, the performance of female and male Triatoma infestans in the 5th instar of development, in xenodiagnosis for Chagas' disease. Xenodiagnosis were done in 40 patients with chronic infectans. For each diagnosis 20 nymphs female and 20 nymphs males were used, which were weighed immediately before and after the meal. Intestinal contents were examined about 20, 30, 60 and 90 days after the xenodiagnosis application. The females and males ingested the mean of 230 and 210 mg of blood, respectively. The results revealed positivity of 15 (37.5%) out of 40 xenodiagnosis, but any of the positive tests show 100% of the nymphs, female and/or male infected by T. cruzi. The females ingested significantly more blood than the males; this is coincidental with the higher female positivation to T. cruzi here observed. Our results suggest that the female nymphs seem able to increase the sensibility of the xenodiagnosis for chronic patients with Chagas' disease being necessary further studies are necessary to confirm this hypothesis.

Influence of the number of questions on the student's achievement in tests of anatomy.

The authors compare student's achievement in tests with low and moderately high number of questions requiring short answers. Five groups of Medical School students underwent their regular Anatomy evaluation tests, which consisted of 13 questions (one group), 15 (two groups) and 25 (two groups). In each group five questions were chosen at random, average scores being calculated from their marks. These scores were statistically compared to the ones calculated from the marks given to the full-length evaluation tests; it became quite evidente that averages go up when the number of questions is increased. Putting the averages in terms of A, B, C and D scores (very good, good, regular and insufficient), it was noted that failure to reach at least the C score is inversely proportional to the number of questions. The results are discussed in terms of determining the most proper number of questions to be given in a test.

Contour mapping of the temporal-spatial progression of a contagious disease.

A methodology for contour-map study of contagious-disease epidemics is presented. Its application is exemplified in a smallpox epidemic occurring in a small Brazilian town. Computer-controlled contour-mapping of dates of introduction of variola minor into 169 households and the coordinates of the affected dwellings did not show a single contour pattern, but a group of subareal patterns of within-household outbreaks. Introduction by adults and pre-school children were distributed throughout the whole city area. However, introduction by school children formed two groups of contours and of affected dwellings. Each group was included in a discrete area corresponding to the zone of pupil recruitment of the two schools enrolling 91% of the school-child introductory-cases. The latter were responsible for introduction of the disease into 45% of the city's affected households. Altogether, both zones practically covered the whole city area. In either zone, several patterns surrounded the corresponding school. Even though no time value was entered for any school, contour maps clearly evidenced the influence of those two schools on spread of the epidemic. An estimated rate of linear spread of variola minor was 1.35 m per day in a city subarea.

Temporal-spatial-social parameters in the spread of contagious disease.

A conceptual theoretical model was built on the basis of prominent concepts of the generally accepted knowledge on the spread of contagious disease. Subsequently, the model was applied to a real epidemic of variola minor (the mild form of smallpox) and four phases of the epidemic were disclosed. The phases discriminated themselves through their relationships to invasion of certain city subdivisions and rural districts and particularly, through the type of social units involved and the type of persons introducing the disease into these units. Introduction of variola minor into day schools with further spread in classes passed across a threshold which led to a boosting of the number of households affected and of the area involved in the epidemic. The phase of maximal spread corresponded to this operation of day schools as diffusion agencies. The temporal-spatial-social correspondence suggests that phases of the epidemic did occur as a result of periodic variation of the mechanism of spread.

Immunoglobulin G and immunoglobulin M enzyme-linked immunosorbent assays and defined toxoplasmosis serological patterns.

Enzyme-linked immunosorbent assay (ELISA) for toxoplasmosis was evaluated in serum samples presenting defined toxoplasmosis serological patterns, as determined by results in immunoglobulin (Ig)G and IgM immunofluorescence (IgG-IF, IgM-IF), hemagglutination, and complement fixation tests. ELISA was carried out with alkaline phosphatase-labeled anti-IgG and anti-IgM antibodies. Serum titer was expressed as the serum dilution end point determined by mere observation of color development in the test. A straight agreement was found between IgG-ELISA and IgG-IF titers, both in group A sera of ancient infections (patterns II and III) and group B sera of recent infections (pattern I). A similar agreement was found between IgG-ELISA and hemagglutination titers in group A sera, for which coincident IgG-IF and hemagglutination titers are also frequent. However, in group B sera, in spite of the same toxoplasma extract being used to sensitize both plastic surfaces and erythrocytes, IgG-ELISA titers were much higher than hemagglutination titers, in a way similar to that observed for IgG-IF titers. IgM-ELISA was positive in every group B serum, with higher titers than corresponding IgM-IF titers. Occasional low-titered positive IgM-ELISA results were seen for group A sera, sometimes due to IgM-antiglobulin antibodies. An easy test to perform, ELISA seems to be an adequate substitute for toxoplasmosis IF tests for routine purposes.

[Perianal manifestations in Crohn's disease]. / Manifestações perianais na doença de Crohn.

UNLABELLED: A total of 114 of 195 patients with Crohn's disease had perianal involvement. The average age at the beginning of symptomatology was 30.3 years. The interval between symptoms and diagnosis was 3.1 years. PAC was associated with colonic disease and in these patients, was multiple. PAC preceded intestinal disease in 11 percent, was coincident in 66 percent and appeared later in 23 percent. Sixty one patients (53.5%) were operated on 104 times (1.7 operations per patient). None of these patients developed faecal incontinence. Two patients were treated with hyperbaric oxygenation. The association of perianal disease and extra-intestinal manifestation occurred in 76 patients. There was no association in 38 patients. Forty patients had extra-intestinal manifestation without perianal disease. Twenty two patients had panproctocolectomy because of perianal disease. Twenty one had a stoma, with or without intestinal resection. The stoma improved perianal symptoms, but all remain defunctioned. After mean follow-up of 8.8 years, 45 patients present some kind of perianal complication. CONCLUSION: the surgical treatment of perianal disease well indicated and performed don't result in incontinence; PAC combined with colonic or rectal disease is associated with higher need of performing a proctocolectomy or a defunctioning stoma. Only 22.8 percent presented resolution of perianal disease maintaining anal sphincter function.

IgG, IgM and IgA antibody response for the diagnosis and follow-up of paracoccidioidomycosis: comparison of counterimmunoelectrophoresis and complement fixation.

IgG, IgM and IgA antibodies to GP43 (glycoprotein fraction of Paracoccidioides brasiliensis) were measured by ELISA in 63 samples from 23 patients with paracoccidioidomycosis before and twice after chemotherapy was started. Antibodies against P. brasiliensis were detected by indirect immunofluorescence (IF) (IgG, IgM and IgA isotypes), counterimmunoelectrophoresis (CIE) and complement fixation. Two control groups composed of 19 healthy individuals and 12 patients with other diseases (six with histoplasmosis, three with tuberculosis and three with other mycoses). The highest efficiency percentages were found with IgG and IgA-ELISA (100%), IgG-IF (96.2%), CIE (94.4%) and the lowest with CF (75.9%). Highest positive and negative predictive values (100%) were observed for IgG and IgA ELISA. IgG and IgM-ELISA antibodies are more often found in patients with acute than chronic disease (P = 0.01). Four to six months after treatment follow-up showed decreased levels of IgG and IgM-ELISA for acute cases and decreased titres of CIE for chronic cases in relation to pretreatment levels. This study suggests that IgG-ELISA anti-GP43 represents a good marker to monitor clinical response to therapy.

Frequencia de anticorpos para rotavirus em habitantes da cidade de Sao Paulo em 1980-82. / Frequency of antibodies to rotavirus in inhabitants of the city of Sao Paulo in 1980-82

Entre maio de 1980 e julho de 1982 foram selecionadas ao acaso 1.202 amostras de sangue de individuos encaminhados do Instituto Adolfo Lutz. Usou-se o metodo da inibicao da hemaglutinacao, visando titular anticorpos para rotavirus. O antigeno usado foi obtido da cepa de virus SA-11.Os resultados de 426 soros de criancas entre 0-23 meses de idade indicam que a distribuicao da infeccao e semelhante aquela encontrada em outros paises. Diminuicao dos anticorpos maternos ocorreu aos 6-7 meses de idade e o pico da frequencia ocorreu nos 1o. e 2o. anos de vida. Em seguida nao houve variacoes de interesse inclusive ate a faixa igual ou maior de 70 anos sugerindo reinfeccoes no decorrer da vida. Estatisticamente, os resultados em 738 amostras de soros entre 2-59 anos nao diferiram significantemente dos obtidos pelo metodo ELISA em outros paises, razao pela qual o metodo, alem de menos oneroso, e mais simples e deve ser usado em inqueritos sorologicos e estudos retrospectivos de surtos e/ou epidemias da infeccao