Efficiency of indirect immunofluorescence assay as a confirmatory test for the diagnosis of human retrovirus infection (HIV-1 and HTLV-I/II) in different at risk populations

We compared the indirect immunofluorescence assay (IFA) with Western blot (Wb) as a confirmatory method to detect antibodies anti retrovirus (HIV-1 and HTLV-I/II). Positive and negative HIV-1 and HTLV-I/II serum samples from different risk populations were studied. Sensitivity, specificity, positive, negative predictive and kappa index values were assayed, to assess the IFA efficiency versus Wb. The following cell lines were used as a source of viral antigens: H9 ( HTLV-III b); MT-2 and MT-4 (persistently infected with HTLV-I) and MO-T (persistently infected with HTLV-II). Sensitivity and specificity rates for HIV-1 were 96.80% and 98.60% respectively, while predictive positive and negative values were 99.50% and 92.00% respectively. No differences were found in HIV IFA performance between the various populations studied. As for IFA HTLV system, the sensitivity and specificity values were 97.91% and 100% respectively with positive and negative predictive values of 100% and 97.92%. Moreover, the sensitivity of the IFA for HTLV-I/II proved to be higher when the samples were tested simultaneously against both antigens (HTLV-I-MT-2 and HTLV-II-MO-T). The overall IFA efficiency for HIV-1 and HTLV-I/II-MT-2 antibody detection probed to be very satisfactory with an excellent correlation with Wb (Kappa indexes 0.93 and 0.98 respectively). These results confirmed that the IFA is a sensitive and specific alternative method for the confirmatory diagnosis of HIV-1 and HTLV-I/II infection in populations at different levels of risk to acquire the infection and suggest that IFA could be included in the serologic diagnostic algorithm.

Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population

This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas’ Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 people), by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was applied to 385 people and 454 blood samples were collected on filter paper in order to detect L. chagasi antibodies by ELISA and IFAT and T. cruzi antibodies by ELISA. T. cruzi seroprevalence was 8.7% by ELISA, L. chagasi was 4.6% and 5.1% by IFAT and ELISA, respectively. ELISA sensitivity and specificity for L. chagasi antibodies were 57% and 97.5% respectively, as compared to the IFAT. Leishmanin skin test positivity was 19%. L. chagasi infection prevalence, being defined as a positive result in the three-immunodiagnostic tests, was 17.1%. Additionally, 2.7% of the population studied was positive to both L. chagasi and T. cruzi, showing a possible cross-reaction. L. chagasi and T. cruzi seropositivity increased with age, while no association with gender was observed. Age (p<0.007), number of inhabitants (p<0.05), floor material (p<0.03) and recognition of vector (p<0.01) were associated with T. cruzi infection, whilst age ( p<0.007) and dwelling improvement (p<0.02) were associated with L. chagasi infection. It is necessary to evaluate the long-term impact of the dwelling improvement programme on these parasitic infections in this community.

Identification of risk factors for death from tetanus in Pernambuco, Brazil: a case-control study

A case-control study was conducted to identify risk factors for death from tetanus in the State of Pernambuco, Brazil. Information was obtained from medical records of 152 cases and 152 controls, admitted to the tetanus unit in the State University Hospital, in Recife, from 1990 to 1995. Variables were grouped in three different sets. Crude and adjusted odds ratios, p-values and 95% confidence intervals were estimated. Variables selected in the multivariate analysis in each set were controlled for the effect of those selected in the others. All factors related to the disease progression - incubation period, time elapsed between the occurrence of the first tetanus symptom and admission, and period of onset - showed a statistically significant association with death from tetanus. Similarly, signs and/or symptoms occurring on admission or in the following 24 hours (second set): reflex spasms, neck stiffness, respiratory signs/symptoms and respiratory failure requiring artificial ventilation (third set) were associated with death from tetanus even when adjusted for the effect of the others.

Hepatitis C virus seroprevalence and risk factors among patients with HIV infection

The objective of this study was to evaluate the prevalence and risk factors associated with HCV infection in a group of HIV seropositive patients. We analyzed the medical records of 1,457 patients. All patients were tested for HCV infection by third generation ELISA. Whenever possible, a sample of the positive patients was also tested for HCV by PCR. HCV positive patients were analyzed according to their risk factors for both infections. The prevalence of anti-HCV positive patients was 17.7% (258 patients). Eighty-two (82) of these patients were also tested by PCR and 81 were positive for HCV virus (98%). One hundred fifty-one (58.5%) were intravenous drug users (IDU); 42 (16.3%) were sexual partners of HIV patients; 23 (8.9%) were homosexual males; 12 (4.7%) had received blood transfusion; 61 (17.5%) had promiscuous sexual habits; 14 (5.4%) denied any risk factor; 12 (4.7%) were sexual partners of IDU. Two hundred four patients mentioned only one risk factor. Among them, 28 (10.9%) were sexual partners of HIV-positive patients. Although intravenous drug use was the most important risk factor for co-infection, sexual transmission seemed to contribute to the high HCV seroprevalence in this group of patients.

Sound levels and risk perceptions of music students during classes

It is well recognized that professional musicians are at risk of hearing damage due to the exposure to high sound pressure levels during music playing. However, it is important to recognize that the musicians’ exposure may start early in the course of their training as students in the classroom and at home. Studies regarding sound exposure of music students and their hearing disorders are scarce and do not take into account important influencing variables. Therefore, this study aimed to describe sound level exposures of music students at different music styles, classes, and according to the instrument played. Further, this investigation attempted to analyze the perceptions of students in relation to exposure to loud music and consequent health risks, as well as to characterize preventive behaviors. The results showed that music students are exposed to high sound levels in the course of their academic activity. This exposure is potentiated by practice outside the school and other external activities. Differences were found between music style, instruments, and classes. Tinnitus, hyperacusis, diplacusis, and sound distortion were reported by the students. However, students were not entirely aware of the health risks related to exposure to high sound pressure levels. These findings reflect the importance of starting intervention in relation to noise risk reduction at an early stage, when musicians are commencing their activity as students.

New prevalence estimate of TT virus (TTV) infection in low- and high-risk population from São Paulo, Brazil

The prevalence of TT virus (TTV) infection was investigated by Polymerase Chain Reaction (PCR) in low- (blood donors and healthy children/adolescents) and high-risk (hemophiliacs) groups from São Paulo, Brazil. Primers based on the untranslated region (UTR) of the viral genome proved to be much more ubiquitous, leading to much higher frequencies for both groups ( > or = 81%) than the earlier N22-PCR directed to the open reading frame 1 (blood donors, 5.5%, and hemophiliacs, 42.3%). The UTR-PCR also revealed an interesting profile for healthy children/adolescents: very high prevalence at the early years and significant decrease in male teenagers. The N22-PCR, in turn, demonstrated higher frequency in hemophiliacs treated with fresh blood products (58%), than in those treated with virus-inactivated clotting factors (9.4%) and blood donors (5.5%).

Defining risk acceptance criteria in occupational settings: A case study in the furniture industrial sector

The use of appropriate acceptance criteria in the risk assessment process for occupational accidents is an important issue but often overlooked in the literature, particularly when new risk assessment methods are proposed and discussed. In most cases, there is no information on how or by whom they were defined, or even how companies can adapt them to their own circumstances. Bearing this in mind, this study analysed the problem of the definition of risk acceptance criteria for occupational settings, defining the quantitative acceptance criteria for the specific case study of the Portuguese furniture industrial sector. The key steps to be considered in formulating acceptance criteria were analysed in the literature review. By applying the identified steps, the acceptance criteria for the furniture industrial sector were then defined. The Cumulative Distribution Function (CDF) for the injury statistics of the industrial sector was identified as the maximum tolerable risk level. The acceptable threshold was defined by adjusting the CDF to the Occupational, Safety & Health (OSH) practitioners’ risk acceptance judgement. Adjustments of acceptance criteria to the companies’ safety cultures were exemplified by adjusting the Burr distribution parameters. An example of a risk matrix was also used to demonstrate the integration of the defined acceptance criteria into a risk metric. This work has provided substantial contributions to the issue of acceptance criteria for occupational accidents, which may be useful in overcoming the practical difficulties faced by authorities, companies and experts.

Canine visceral leishmaniasis in Barra de Guaratiba, Rio de Janeiro, Brazil: assessment of risk factors

Barra de Guaratiba is a coastal area of the city of Rio de Janeiro where American visceral leishmaniasis (AVL) is endemic. Although control measures including killing of dogs and use of insecticides have been applied at this locality, the canine seroprevalence remains at 25% and during 1995 and 1997 eight autochthonous human cases were notified. In order to evaluate factors related to the increase of the risk for Leishmania (Leishmania) chagasi infection in dogs we have screened 365 dogs by anti-Leishmania immunofluorescent antibody test (IFAT) and captured sandflies in the domestic and peridomestic environment. Some variables related to the infection were assessed by uni- and multivariate analysis. The distance of the residence from the forest border, its altitude and the presence of the opossum Didelphis marsupialis in the backyard, were found predictor factors for L. (L.) chagasi infection in dogs in Barra de Guaratiba. The presence of Lutzomyia longipalpis in the peridomestic environment indicates the possibility of appearence of new human cases. Our data also suggest the presence of a sylvatic enzootic cycle at this locality.

Autonomous bathymetry for risk assessment with ROAZ robotic surface vehicle

The use of unmanned marine robotic vehicles in bathymetric surveys is discussed. This paper presents recent results in autonomous bathymetric missions with the ROAZ autonomous surface vehicle. In particular, robotic surface vehicles such as ROAZ provide an efficient tool in risk assessment for shallow water environments and water land interface zones as the near surf zone in marine coast. ROAZ is an ocean capable catamaran for distinct oceanographic missions, and with the goal to fill the gap were other hydrographic surveys vehicles/systems are not compiled to operate, like very shallow water rivers and marine coastline surf zones. Therefore, the use of robotic systems for risk assessment is validated through several missions performed either in river scenario (in a very shallow water conditions) and in marine coastlines.

Aborto recorrente das causas na mulher às consequências para o casal

RESUMO: O aborto recorrente (AR) é um evento extremamente traumático com grande impacto na vida dos casais. Apesar de avanços significativos verificados na investigação médica, cerca de 50% dos casos continua sem uma causa identificada. Alguns aspectos como a caracterização inadequada das doentes e das perdas gestacionais, assim como diferentes metodologias utilizadas no seu estudo, têm influenciado a prevalência de alguns dos factores causais e dificultado a compreensão do AR. Da mesma forma, pouco se sabe sobre as diferenças de género na vivência psicológica do aborto recorrente e das suas eventuais repercussões para o relacionamento do casal, centrando-se os poucos estudos existentes preferencialmente na mulher. Por esta razão, o objectivo desta tese foi a caracterização dos factores médicos associados ao AR e das consequências psicológicas desta entidade, contribuindo para promover estratégias clínicas baseadas na evidência específica. Na primeira parte desta tese (capítulos 1 e 2), após uma breve introdução geral e através de uma revisão da literatura, efectua-se uma reflexão sobre o tema, abordando a epidemiologia do aborto recorrente, os factores médicos e os aspectos psicológicos associados. Nos capítulos 3 e 4 descrevemos três estudos efectuados em mulheres portuguesas com aborto recorrente. O primeiro estudo teve por objectivo caracterizar os factores médicos e determinar o padrão da perda recorrente de gravidez, numa coorte de mulheres submetidas a um protocolo de diagnóstico definido. As participantes foram agrupadas de acordo com a paridade (AR primário ou secundário) e a idade gestacional das perdas (embrionárias ou fetais). As anomalias da cavidade uterina, a SAAF e as translocações equilibradas parentais foram os factores mais prevalentes. 15,6% das participantes eram obesas. Em 55,5% dos casos não foi identificado nenhum factor. A história obstétrica materna influenciou significativamente os resultados encontrados: os factores anatómicos e a SAAF foram mais prevalentes em nulíparas e as perdas inexplicadas foram mais frequentes em mulheres com AR secundário. Assim, os nossos dados reforçam os resultados de pesquisas anteriores sobre a importância da obesidade, da síndrome de anticorpos antifosfolípidos e das anomalias uterinas estruturais como factores associados ao AR e mostram que os a paridade é um moderador da importância desses factores. Capítulo 6 94 A ausência de resultados consensuais na literatura sobre a etiologia do AR condiciona a pesquisa sistemática de alguns factores, envolvendo exames dispendiosos, muitas vezes sem que exista evidência que suporte a sua associação com esta entidade. A trombofilia hereditária é uma das condições frequentemente investigadas nestas doentes. O nosso segundo estudo pretende contribuir para clarificar o papel de duas mutações (factor V Leiden e protrombina G20210A) na perda recorrente de gravidez e esclarecer a necessidade do seu rastreio nestas situações. Foi efectuada a pesquisa destes polimorfismos em 100 mulheres com AR inexplicado e num grupo de controlo de multíparas sem história de perdas de gravidez. Na nossa amostra não se verificou uma associação entre perdas embrionárias recorrentes e estas mutações. Nas mulheres com este tipo de perdas, a prevalência do FLV foi inclusive menor do que a verificada nos controlos. Pelo contrário, nas participantes com perdas fetais a prevalência destes polimorfismos foi muito superior à verificada nos controlos, sugerindo uma possível associação entre estas duas entidades. A pequena dimensão deste último subgrupo de mulheres, não nos permitiu contudo tirar conclusões. Uma investigação prospectiva multicêntrica é necessária antes de recomendar a pesquisa da trombofilia hereditária na investigação do AR. Procurámos incluir também nesta tese uma dimensão psicológica e contribuir assim para o conhecimento dos processos relacionais originados pelo AR. No terceiro estudo foram investigadas as diferenças de género na vivência do AR e o seu impacto no relacionamento e sexualidade do casal. Participaram neste estudo 30 casais sem filhos, com pelo menos 3 abortos espontâneos consecutivos. Cada membro do casal respondeu a um conjunto de questionários (Impact of Events Scale, Perinatal Grief Scale, Partnership Questionnaire e Intimate Relationship Scale). Os resultados mostram que as mulheres sofrem mais intensamente do que os homens com o AR, relacionando-se a intensidade do seu sofrimento com a qualidade do relacionamento conjugal. A sexualidade do casal é também afectada pelo stress e pelo sofrimento associados ao AR. Uma avaliação e acompanhamento deste tipo de problemas são imprescindíveis para ajudar estes casais a manterem a qualidade afectiva e sexual da sua relação. Finalmente, no capítulo 5 sumariámos as conclusões de toda a contribuição pessoal para a investigação sobre os factores associados e repercussões para o casal da perda recorrente de gravidez.-------------------ABSTRACT: Recurrent miscarriage (RM), a rare condition, has been described as a traumatic event for couples. Parental chromosomal anomalies, maternal thrombophilic disorders and structural uterine anomalies have been directly associated with RM. However, despite significant advances in medical research, the vast majority of cases remain unexplained. Aspects as the ethnic diversity of the population with different expression of genes, the inappropriate characterization of patients and of pregnancy losses, as well as different methodologies used in their study, have influenced the prevalence of etiological factors and have hampered the understanding of this problem. Similarly, little is known about gender differences in psychological experience of RM and its implications for the relationship of the couple. The first objective of this thesis is the characterization of the medical factors and of the psychological consequences related with RM, in the Portuguese population, helping to promote specific evidence-based clinical strategies. In the first part of this thesis, and after a brief general introduction (Chapter 1), a critical review of literature on the definition, the epidemiology and the dimensions involved, with a special emphasis on associated medical and psychological aspects of recurrent miscarriage, is presented (Chapter 2). In Chapters 3 and 4 we describe three studies carried out in Portuguese couples with RM. The first study aimed to investigate the etiological factors and the pattern of pregnancy loss in a cohort of women with RM. Subjects were divided in groups according to their parity (primary or secondary RM) and time of pregnancy loss (embryonic or fetal). Parental chromosome anomalies, uterine anomalies and antiphospholipid syndrome were the most prevalent medical factors. 15.6% of the women were obese. In the majority of cases (55.5%) no identifiable cause was detected. Parity influenced significantly our results. There was a higher prevalence of anatomic factors and antiphospholipid syndrome in primary RM. On the other hand, unexplained losses were more frequent in secondary RM. Except for the parental chromosomal abnormalities; the frequency of risk factors was similar among women with fetal or embryonic losses. Our data emphasizes the results of previous research on the importance of obesity, antiphospholipid syndrome and structural uterine abnormalities as known risk factors for RM, and shows that parity is an important moderator of the weight of those risk factors. Our second study aims to clarify the role of two mutations (factor V Leiden and prothrombin G20210A) and elucidate the need for their screening in Portuguese women with RM. FVL and PT G20210A analysis was carried out in 100 women with three or more consecutive miscarriages and a control group of 100 parous controls with no history of pregnancy losses. Secondary analysis was made regarding gestational age at miscarriage (embryonic and fetal loss). Overall the prevalence of FVL and PT G20210A was similar in RM women compared with controls. In the RM embryonic subgroup of women, FVL prevalence was inclusively lower than that of controls. Conversely in women with fetal losses both polymorphisms were much more frequent, although statistical significance was not reached due to the small size of this subgroup of patients. These data indicate that inherited maternal thrombophilia is not associated with RM prior to 10 weeks of gestation. Therefore, its screening is not indicated as an initial approach in Portuguese women with RM and a negative personal history of thromboembolic.96 Our second study aims to clarify the role of two mutations (factor V Leiden and prothrombin G20210A) and elucidate the need for their screening in Portuguese women with RM. FVL and PT G20210A analysis was carried out in 100 women with three or more consecutive miscarriages and a control group of 100 parous controls with no history of pregnancy losses. Secondary analysis was made regarding gestational age at miscarriage (embryonic and fetal loss). Overall the prevalence of FVL and PT G20210A was similar in RM women compared with controls. In the RM embryonic subgroup of women, FVL prevalence was inclusively lower than that of controls. Conversely in women with fetal losses both polymorphisms were much more frequent, although statistical significance was not reached due to the small size of this subgroup of patients. These data indicate that inherited maternal thrombophilia is not associated with RM prior to 10 weeks of gestation. Therefore, its screening is not indicated as an initial approach in Portuguese women with RM and a negative personal history of thromboembolic. In our third study, we investigate gender differences in RM experience and its impact on the couple's relationship and sexuality. Each member of 30 couples with RM answered a set of questionnaires, including the Impact of Events Scale (Horowitz et al., 1979), the Perinatal Grief Scale (Toedter et al., 1988), the Partnership Questionnaire (Hahlweg, 1979) and the Intimate Relationship Scale (Hetherington e Soeken, 1990). Results showed that men do grieve, but less intensely than women. Although the quality of the couple‟s relationship seemed not to be adversely affected by RM, both partners described sexual changes after those events. Grief was related to the quality of communication in the couple for women, and to the quality of sex life for men. An understanding of such issues is critical in helping these couples to maintain sexual and affective quality of their relationship. Finally, in Chapter 5, conclusions and clinical implications of all personal contribution to the investigation on associated factors and relational consequences of recurrent miscarriage are presented.

Risk of Surgery for Congenital Heart Disease in the Adult: a Multicentered European Study

BACKGROUND: Surgery for congenital heart disease (CHD) has changed considerably during the last three decades. The results of primary repair have steadily improved, to allow treating almost all patients within the pediatric age; nonetheless an increasing population of adult patients requires surgical treatment. The objective of this study is to present the early surgical results of patients who require surgery for CHD in the adult population within a multicentered European study population. METHODS: Data relative to the hospital course of 2,012 adult patients (age > or = 18 years) who required surgical treatment for CHD from January 1, 1997 through December 31, 2004 were reviewed. Nineteen cardiothoracic centers from 13 European countries contributed to the data collection. RESULTS: Mean age at surgery was 34.4 +/- 14.53 years. Most of the operations were corrective procedures (1,509 patients, 75%), followed by reoperations (464 patients, 23.1%) and palliative procedures (39 patients, 1.9%). Six hundred forty-nine patients (32.2%) required surgical closure of an isolated ostium secundum atrial septal defect. Overall hospital mortality was 2%. Preoperative cyanosis, arrhythmias, and NYHA class III-IV, proved significant risk factors for hospital mortality. Follow-up data were available in 1,342 of 1,972 patients (68%) who were discharged home. Late deaths occurred in 6 patients (0.5%). Overall survival probability was 97% at 60 months, which is higher for corrective procedures (98.2%) if compared with reoperations (94.1%) and palliations (86.1%). CONCLUSIONS: Surgical treatment of CHD in adult patients, in specialized cardiac units, proved quite safe, beneficial, and low-risk.

Study of antiretroviral mutants in HIV patients with treatment failures and the effect of risk factors in the virological failures

INTRODUCTION: Information about HIV phenotypes of resistant to available ART and the influence of different risk factors on virological failures (VF) in Costa Rican HIV positive patients prior or during HAART is unknown. MATERIALS AND METHODS: Eighty nine samples, 72 VF and 17 basal (before treatment) were analyzed by examining resistant mutants in reverse transcriptase (RT) and protease (PT) regions using Trugene or LIPA genotyping kits. Sixty eight control patients were selected and relevant information was collected in a questionnaire. RESULTS: Poor adherence, presence of resistant mutations and number of treatment's changes were the only significant factors found (p = 0.006, 0.04 and 0.01 respectively). From 66 sequenced samples, 78%, 50% and 50% showed resistance to NRTI (nucleoside reverse transcriptase inhibitors), NNRT (non-nucleoside reverse transcriptase inhibitors) and PI (protease inhibitors), respectively. The most frequent mutations were M41L, M184V, and T215FY in RT and L62PI, L10FIRV and M36I in PT. DISCUSSION: The most important factor related to treatment response in this study was adherence to treatment. Mutations in RT were related to the treatment failure while the ones found in PT were secondary mutations which have been previously described to influence the selection of primary resistance mutations in these regions. The study reveals the urgency to detect resistant mutations in VF to be considered by physicians for selection of treatment schedule, to analyze basal HIV patients for monitoring of the spread of resistant mutations and the importance to reinforce the adherence in the patients for overall treatment outcome.