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F Zicker

Publications and source records attributed to F Zicker.

At least 37 records · Page 2Linked to original sources
PubMed1995

[The protective efficacy of BCG against leprosy in São Paulo, Brazil].

The protection against leprosy conferred by BCG vaccination was evaluated in a case-control study. Selected for the study were 97 patients under 16 years of age who had been diagnosed with leprosy (cases) and 385 healthy persons (controls), who were matched according to sex, age, place of residence, and type of contact (intra- or extradomicilliary). The cases were selected from a register of active cases as well as a series of new leprosy patients treated in 50 centers in the city of São Paulo, Brasil. To estimate the protective effect of BCG, the prevalences of BCG scars among cases and controls were compared. The presence of one or more scars was associated with a protective efficacy of 90% (95% confidence interval: 78%-96%). Stratified analysis by age group, sex, socioeconomic level, and clinical form of leprosy did not reveal any important differences in the protection conferred by the vaccine. The significance of these findings and the appropriateness of using BCG in leprosy control programs is discussed.

Adolescent↗
PubMed1994

Prevalence and risk factors for HBV infection among street youth in central Brazil.

PURPOSE: A seroprevalence survey was carried out among 496 street adolescents from 9 to 20 years old in central Brazil to determine the prevalence of hepatitis B (HBV) markers, as well as to assess the role of potential risk factors. RESULTS: The findings reveal that 20.4% of the participants were homeless adolescents without family links, living and/or working on the streets. The age at first sexual intercourse was as low as 9 years old, and approximately 60% of this population had had at least one sexual relationship by the age of thirteen, indicating prepubertal initiation of sexual experiences among street adolescents. 13.5% were HBV marker-positive (anti-HBc) and 2.0% had antigenemia. Street-based youth had a higher HBV marker-positive rate when compared to home-based teens (OR = 4.1, 95% CI: 2.1-8.5) and, similarly, higher HBV prevalence was obtained for those reporting sexual activity versus the group without sexual activity (OR = 2.1, 95% CI: 1.1-3.9), even after adjusting for potential confounders. CONCLUSIONS: We have found that street youth, particularly street-based adolescents, should be considered at-risk group for hepatitis B infection in our region. These findings may be used as a baseline information for policy changes not only in hepatitis B prevention but also to reverse the scenario of adolescents sexual abuse.

Adolescent↗
PubMed1994

Agreement between histopathological results in clinically diagnosed cases of indeterminate leprosy in São Paulo, Brazil.

Histopathological slides from skin biopsies of fifty-seven self-reporting patients diagnosed as indeterminate leprosy by the Leprosy Control Programme in São Paulo, were sent to three independent histopathologists. Agreement between the reports were based on the following diagnosis: "indeterminate leprosy", "suggestive leprosy" or "no leprosy". A great variation was observed in the interpretation of the histopathological examination. The three pathologists reported "indeterminate leprosy" respectively in 7.0%, 54.4% and 84.2%, of the cases studied. A kappa index of agreement between any two pathologists ranged from 0.08 to 0.32, showing poor agreement between observers. Agreement improved by pooling together the reports "suggestive leprosy" and "indeterminate leprosy". The three pathologists agreed in the results of 24 biopsies of the 27 classified as leprosy by any one of the three observers. Eight cases were considered as "no leprosy" by all pathologists. Higher agreement indices were obtained for positive and negative proportionate concordance between any two examiners. The implications of the variation in the diagnosis of indeterminate leprosy and early leprosy are discussed in the context of public health and case-management.

Brazil↗
PubMed1992

Surveillance of Trypanosoma cruzi transmission by serological screening of schoolchildren.

The seroprevalence of Trypanosoma cruzi infection among children is a sensitive indicator for assessing the effectiveness of programmes for control of Chagas disease. In this study we report the result of a cross-sectional serological survey carried out among schoolchildren living in a poor rural area in central Brazil. Eluates of blood collected on filter-paper were tested for anti-T. cruzi antibodies using immunofluorescence, haemagglutination, and enzyme-linked immunosorbent assays. The overall seroprevalence of T. cruzi infection was 7.9%, which compared with the findings of the national survey carried out in 1975-80 indicates that a twofold-to-threefold reduction in prevalence has occurred over the last 10 years. This is consistent with a reduction of transmission in the area, probably related to vector control efforts. Based on our results, the incidence of new cases was estimated to be 44 per annum in the study region. In rural areas with a scattered population, surveillance of T. cruzi transmission by serological screening of children at school entry is more practical and economical than entomological evaluation for assessing both the risk of transmission in the community and the efficacy of vector control measures. A sample size of around 1000 schoolchildren is sufficient to detect prevalences as low as 2%, and such an approach would be practical and applicable to most areas where Chagas disease is endemic.

Antibodies, Protozoan↗
PubMed1992

Protective effect of intradermal BCG against leprosy; a case-control study in central Brazil.

A case-control study was undertaken to evaluate the protective efficacy of intradermal BCG against leprosy in a high-endemic area of leprosy in central Brazil. Sixty-two cases and 186 controls were included in the study. Cases were all newly diagnosed leprosy patients under 16 years of age attending an outpatient health service, and all of them were schoolchildren. Three controls under 16 years old, frequency matched by sex and age group, were selected from schools geographically located in the area from which the cases came. The presence of BCG was negatively associated with leprosy, indicating a 5.3 risk of leprosy for those nonvaccinated and protective efficacy of 81%. Paucibacillary patients were more likely to have a BCG scar than multibacillary patients.

Adolescent↗
PubMed1992

Serologic screening for Trypanosoma cruzi among blood donors in central Brazil.

The study reported here compares results obtained by blood banks screening sera for chagasic (Trypanosoma cruzi) infection with results obtained by the Chagas' Disease Reference Laboratory of the Federal University of Goiás in Goiânia, Brazil. It also evaluates results obtained using the ELISA technique to screen the study sera. The survey used data from six of eight blood banks serving the city of Goiânia, an urban region of Central Brazil where Chagas' disease is highly endemic. The survey population consisted of 1,513 voluntary first-time blood donors whose donations occurred between October 1988 and April 1989. This group included 50% of all the first-time blood donors in that period. The six participating blood banks, which accounted for about 90% of all blood donations in Goiânia during the study period, routinely used indirect hemagglutination (IHA) and complement fixation (CF) tests to screen sera for antibodies to T. cruzi. Comparison of the results provided by the blood banks with the reference laboratory's results indicated a relative sensitivity of 77%, which ranged from 50% to 100% depending on the blood bank studied. The comparison, which found 12 false negative results, indicated that transfusions of infected blood might have occurred despite the serologic screening performed by the blood banks. Relative to the standard of positivity established for the study, the enzyme-linked immunosorbent assay (ELISA) technique was found to have a sensitivity of 96.3%. Considering as positive only those sera yielding positive IHA and indirect immunofluorescence (IIF) test results, the ELISA technique yielded 2 false negative and 41 false positive responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Serological screening for Trypanosoma cruzi among blood donors in central Brazil].

The present study compares the results of serological screening for Trypanosoma cruzi infection done at blood banks with results obtained in Chagas' disease studies undertaken by the Reference Laboratory of the Federal University of Goiás (UFG) and evaluates the use of the enzyme-linked immunosorbent assay (ELISA) for this purpose. The study was conducted with data from six of the eight blood banks in the city of Goiânia in central Brazil, an urban area in which this infection is highly endemic. The population studied consisted of 1,513 volunteers who had donated blood for the first time between October 1988 and April 1989. The sample represented 50% of all first-time blood donors during the period. Of these donors, 94% were residents of urban areas, and of these, approximately 26% had migrated from the countryside. Nearly 90% of the blood donations in the city are received at these banks, which normally use the indirect hemagglutination and complement-fixation tests. The samples selected for the study of T. cruzi antibody in first-time blood donors were assayed at the Reference Laboratory of the Federal University of Goiás using the indirect hemagglutination (IH), indirect immunofluorescence (IF), and enzyme-linked immunosorbent assay (ELISA) tests, independently of the serological classification performed by the blood banks. Comparison of the results provided by the latter with the positivity pattern established in the study (IH and IF yielded simultaneous positive results in the Reference Laboratory) revealed a relative sensitivity of 77%, with extremes ranging between 50% and 100%, depending on the blood bank studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Methodological considerations in the interpretation of serologic screening for hepatitis B virus among blood donors].

Between October 1988 and February 1989, 1,033 voluntary first-time blood donors were screened for hepatitis B infection in five blood banks in Goiâna, Central Brazil. The survey was part of a major study designed to estimate seroprevalence of HBsAg and anti-HBs and to discuss methodological issues related to prevalence estimation based on data from blood banks. Donors were interviewed and blood samples were collected and tested for HBsAg and anti-HBs by ELISA tests. Prevalences of 1.9% and 10.9% were obtained for HBsAg and anti-HBs, respectively, and no statistical difference was found between the sexes. Prevalence of anti-HBs increased with age (X2 for trend = 7.9 p = 0.004). The positive predictive value and sensitivity of history of jaundice or hepatitis reported in the interview in detecting seropositives were 13.6% and 2.2%, respectively. The methodological issues, including internal and external validity of HBV prevalence estimated among blood donors are discussed. The potential usefulness of blood banks as a source of morbidity information for surveillance for Hepatitis B virus infection is stressed.

Adolescent↗
PubMed1990

Trypanosoma cruzi infection and electrocardiographic findings among active manual workers. A population-based study in central Brazil.

In a cross sectional survey of the prevalence of Trypanosoma cruzi infection among urban unskilled workers in Goiânia, Brazil, blood samples from 6222 manual workers from seven institutions were examined for anti-Trypanosoma cruzi antibodies by immunofluorescence, ELISA and haemagglutination tests. ECGs were performed and a clinical history was taken from 624 seropositive and a random sample of 529 seronegative subjects. Abnormal ECGs were found in 15.1% of individuals without Trypanosoma cruzi antibodies and in 44.4% of those with antibodies (p less than 0.001). In general, cardiovascular symptoms reported were not associated with seropositivity nor with ECG alterations but dizziness and dyspnoea were more often reported among those with an abnormal tracing (p less than 0.01). The prevalence of ECG abnormalities increased with age in both groups but was higher among those seropositive in all age groups. An odds ratio of 2.0 (95% Cl 1.2-3.1) and 2.9 (95% Cl 1.5-6.3) of ECG abnormalities, for each decade of life, was estimated for seropositive and seronegative subjects, respectively. Relative risks (based on the odds ratios) for various specific ECG abnormalities, comparing seropositive to seronegative individuals, were calculated after adjustment for age, sex and institution. The odds ratio for complete right bundle branch block was 49.9 (95% CL 12.2-203.4); for left anterior hemiblock was 4.1 (2.8-6.0); for large Q/QS waves was 4.2 (2.4-7.3) and for first degree A-V block was 8.5 (2.6-28.1).

Adolescent↗
PubMed1990

[Seroprevalence and risk factors for hepatitis B virus infection by AgHBs and anti-HBs markers in prisoners and prime blood donors].

Two cross-sectional surveys on hepatitis B virus (HBV) infection were carried out among 1,033 volunteer first-time blood donors in five blood banks (3 private, 2 public) and among 201 prisoners in the Penitentiary Center of Industrial Activity, in Goiania, Central Brazil, between June 1988 and February 1989. Those surveys were part of a major study designed to estimate seroprevalence of HBsAg and anti-HBsAg markers by ELISA test, and to study risk factors associated with seropositivity. The presence of any serum marker was considered as previous exposure to HBV. A standard questionnaire was applied to both populations to evaluate previous blood transfusion, number of sexual partners, homo/bisexual activity, history of sexually transmitted diseases, drug abusers, use of parenteral medicine, acupuncture, tattooing and VDRL seropositivity. Seroprevalence varied from 12.8% to 26.4% in blood donors and prisoners, respectively, (p less than 0.05) and increased with age (X2 trend=14.0 p less than 0.05%). Prisoners had higher percentages of all risk factors investigated than blood donors, with the exception of number of sexual partners. Among all risk factors studied, age, imprisonment and tattooing were statistically associated with seropositivity, even after multivariate analysis controlling for age and reclusion. The paper discusses the methodologic issues related to this epidemiologic investigation.

Adult↗
PubMed1990

Physical activity, opportunity for reinfection, and sibling history of heart disease as risk factors for Chagas' cardiopathy.

A case-control study was conducted to examine whether physical activity, sibling history of heart disease (HHD), and length of residence in an area endemic for Chagas' disease were associated with the risk of developing Chagas' cardiopathy. Two hundred forty-seven cases of Chagas' heart disease and 345 seropositive subjects with normal ECG (controls) were selected in a population survey in Goiânia, Brazil. Prevalence ratios for exposure variables were estimated for cases in relation to controls and for subgroups of seropositives with selected ECG abnormalities in relation to controls. Increasing age and male sex were consistently and significantly related to an increased risk of ECG abnormalities. HHD was significantly associated with ECG alterations in 3 of the 5 comparison subgroups (any ECG alteration, right bundle branch block, and left anterior hemiblock). No association was found between length of residence in an area endemic, physical activity, and ECG abnormalities. A sample of 529 seronegative subjects were also examined and the interaction between exposure variables and seropositivity was tested to assess whether the associations found were specific for seropositives. Males were at greater risk of any ECG alteration and left anterior hemiblock in relation to females if they were seropositive. An increasing risk of ventricular premature beats with age was clearer for seropositive than for seronegative subjects. Subjects with HHD were at an increased risk of ECG abnormalities and this was greater in those with a positive serological test (P less than 0.05). The findings suggest a possible geographical clustering or a familial aggregation of cases of Chagas' heart disease.

Adult↗
PubMed1990

Mass screening for Trypanosoma cruzi infections using the immunofluorescence, ELISA and haemagglutination tests on serum samples and on blood eluates from filter-paper.

Methods used to diagnose Trypanosoma cruzi infection differ in their ability to discriminate between sera from infected and uninfected individuals. We compared the results of an immunofluorescence (IF) test, a haemagglutination (HA) test, and an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of T. cruzi infections in a large population-based survey in central Brazil using blood eluates from filter-paper and venous blood samples. The sensitivities of the tests on eluates, compared with results on serum samples, were low: ELISA (78.1%), IF (69.2%) and HA (64.6%). The level of agreement between the tests on eluates was very poor, with the best co-positivity for IF and ELISA. Both the positive and negative predictive values of the three tests on eluates were similar (around 96%) to those for sera. Higher co-positivity values were obtained for the three tests on sera. The implications of these results are discussed in relation to blood screening, routine medical practice, sero-epidemiological surveys, and the follow-up of patients admitted to therapeutic trials.

Brazil↗
PubMed1989

[Serologic screening of infectious diseases in blood banks as an indicator of morbidity in the population].

Screening tests of 62,814 blood donations carried out between October 85 and October 87 in all five blood banks of Goiânia, Central Brazil, were analysed. The private institutions (3 blood banks) collected 80% of all donations and the remaining were collected by public blood banks. Seroprevalence of HIV, HBsAg, Chagas' disease and syphilis were compared with data obtained in the surveillance system and from previous surveys in an attempt to validate this source of health information. A seroprevalence of 0.07% for AIDS (one ELISA test) was calculated, which may suggest the presence of 1900 infected individuals, in the population of the State of Goiás as a whole. This figure seems reasonably close to the official data obtained by compulsory notification. For Chagas' disease, hepatitis B and syphilis seroprevalence of 3.3%, 1.3% and 4.1% were obtained, respectively. The potential usefulness and the limitations of screening in blood banks as a source of reliable morbidity indicator is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Field trials with oxamniquine in a Schistosomiasis mansoni-endemic area.

In Peri-Peri (Minas Gerais), an area endemic for Schistosoma mansoni, 591 inhabitants were examined. A coprological survey showed a prevalence of infection of 43.7%. After clinical examination 220 patients were distributed into three groups for treatment with oxamniquine; in Group 1, 19 children (2 to 15 years) were treated with a single oral dose of drug suspension around 20 mg/kg body weight; in Group 2, 47 children were treated orally with two 10 mg/kg doses with a 6- to 8-hour interval between them; in Group 3, 154 adults were treated with a single dose of about 15 mg/kg (capsules). The most frequent side effects were dizziness, drowsiness, and headache. No statistical difference in frequency of side effects was observed between Groups 1 and 2. Nevertheless, after treatment 32% of the patients in Group 1 complained of dizziness and 13% of headache, whereas in Group 2 the frequencies of these symptoms were 2% and 0%, respectively. Adults (Group 3) had a higher frequency of side effects, their chief complaints being dizziness and drowsiness. In Groups 1, 2, and 3, respectively, 73.7%, 62.2%, and 82.4% of the patients were cured. Statistical analysis did not show any difference in cure rates between children in Groups 1 and 2; however a significance was found when compared with the cure rate observed in adults, showing the drug to be more active in the latter group. In 61.8% of the 40 patients not cured a decrease of over 90% in the number of S. mansoni eggs/g feces was observed. From the data above oxamniquine seems to be an effective schistosomicidal drug suitable for use in endemic areas, although further studies are still needed.

Adolescent↗
PubMedDate not supplied

Seroprevalence of Trypanosoma cruzi infection among unskilled urban workers in central Brazil.

A cross-sectional survey of the prevalence of Trypanosoma cruzi infection was carried out among urban unskilled workers in an endemic area in central Brazil as part of a study to assess the health impact of Chagas disease and to identify risk factors for the evolution of cardiopathy. Blood samples from 5425 male and female workers, aged 15-61 years, from 5 public institutions, were screened by indirect immunofluorescence, enzyme-linked immunosorbent assay and indirect haemagglutination for antibodies to T. cruzi. Seroprevalence varied from 8.8% to 15.6% in the different institutions and increase with age up to 55 years. More stable jobs were associated with lower seroprevalence. Migrants from São Paulo and Minas Gerais presented higher prevalence and a relative risk associated with seropositivity in relation to workers from Goiás of 2.2 (95% confidence limits, 1.4-3.5) and 1.9 (1.6-2.3), respectively.

Adolescent↗
PubMedDate not supplied

Exercise electrocardiogram tests in manual workers with and without antibodies to Trypanosoma cruzi: a population-based study.

Blood pressure, heart rate and electrocardiographic responses to exercise were compared in a group of 125 subjects with antibodies to Trypanosoma cruzi and in 153 seronegative subjects, randomly selected from persons with no evidence of heart disease in a resting electrocardiogram during a cross-sectional survey among apparently healthy manual workers. The mean heart rates and diastolic and systolic blood pressures of those in each group did not differ statistically at different phases of the exercise test and there was no evidence of a difference in physical fitness between those in the 2 groups. An abnormal test was recorded in 26.2% of seropositive, and in 16.1% of seronegative, subjects (odds ratio adjusted for age, sex and body mass index [OR] = 2.0, 95% confidence interval [95% CI] = 1.1-3.8). No significant difference was observed between the 2 groups in the occurrence of hypertensive response to exercise (6.4% among seropositives and 5.9% among seronegatives), ST depression greater than 1 mm (0.8% and 2.0%), supraventricular premature beats (4.8% and 2.6%) or conduction defects (0.8% and 1.3%). Complex ventricular premature beats were recorded more often in seropositive subjects (12.8% and 3.9%; OR = 3.7, 95% CI = 1.4-9.8, P less than 0.01). The risk of an abnormal test increased with age in both groups. A history of cardiovascular symptoms, gender and body mass was not associated with the risk of an abnormal response in the test. The findings suggest that exercise testing might be a routine procedure when subjects with antibodies to T. cruzi are being assessed for participation in potentially high risk activities, such as heavy manual work.

Adult↗