RESUMO
This paper presents a study of the uptake of 2,4,6-tribromophenol (TBP), pentachlorophenol (PCP), and its metabolite pentachloroanisole (PCA) from contaminated sawdust from the forest industry in horticultural products such as apples, raspberries, and fodder maize for cattle feed. The samples were obtained from Bio-Bio Province in South Chile between 2002 and 2006. The analytical parameters of the methodology applied to the different matrices are presented and discussed. The chromatographic method was applied to determine the residues in 413 horticultural product samples. Eleven per cent of fodder maize samples showed detectable or quantifiable levels of PCP, TBP or PCA, 3% of samples presented quantifiable levels, although the concentrations surpassed the maximum allowed concentrations for vegetables (>10 microg kg(-1)) in only two samples. Traces of TBP were detected in eight samples, PCA was detected in 15, and PCP in 14 samples. Based on these results, a risk analysis was performed, indicating a low probability, 0.4% for PCA, 1.6% for TBP and 1.9% for PCP, to find concentrations higher than the allowed maximum. For apples and raspberries, no residues of these compounds were detected. These results indicate that those cultivars directly exposed to sawdust, like fodder maize, could contain detectable residues in several samples. To confirm this observation, a field assay was performed on fodder maize cultivated in the presence of sawdust artificially contaminated with 30 mg of TBP and/or PCP under controlled conditions. The results showed that under the experimental conditions used in the study, TBP can be transferred from sawdust to the plant, with an uptake rate of 0.04% from the TBP applied initially with sawdust but not to the corn ear. Also, the degradation of PCP to PCA was observed in the soil.
Assuntos
Frutas/química , Pentaclorofenol/química , Fenóis/química , Madeira/química , Zea mays/química , Ração Animal/análise , Anisóis/química , Anisóis/metabolismo , Monitoramento Ambiental , Poluentes Ambientais , Fungicidas Industriais/química , Pentaclorofenol/metabolismo , Resíduos de Praguicidas/química , Resíduos de Praguicidas/metabolismo , Rosaceae/química , Rosaceae/metabolismoRESUMO
A cultural feasibility study is defined as one that investigates scientific as well as ethical, behavioral, and social issues in the design of clinical trials. The value of such a broadly defined assessment is illustrated through the presentation of two case studies conducted to prepare for clinical trials to reduce maternal-infant HIV transmission on Cité Soleil, Haiti. The first study addressed issues surrounding a trial of breast-feeding and exclusive bottle-feeding among HIV seropositive mothers. The second study focused on the implementation of a double-blind trial of HIV immune globulin and standard immune globulin to be administered to infants of seropositive mothers shortly after birth. Both cases used focus group interviews with mothers and in-depth interviews with key informants to investigate AIDS-related beliefs, acceptability of trial participation, risks to subjects, and community reactions and repercussions to the trial. Findings point to the difficulties posed by attempts to conduct trial involving complex research designs in socially disadvantaged populations. Recommendations highlight the need to consider the community-wide impact of a trial, and the need to undertake extensive educational preparation of participants to ensure informed consent and adherence to protocols.
PIP: Cultural feasibility studies use ethnographic methods to explore ethical, behavioral, and social issues inherent in the design of proposed clinical trials. This approach was applied in advance of clinical trials aimed at reducing maternal-infant HIV transmission in Cite Soleil, Haiti. The first focused on conditions that would be necessary to conduct a trial of breast feeding versus exclusive bottle feeding by HIV-positive mothers; the second investigated the feasibility of a double-blind trial of administration of a high- titer antibody preparation--HIV immune globulin (HIVIG)--to infants of seropositive mothers shortly after birth. Study methods included focus group discussions with mothers and in-depth interviews with key informants about AIDS-related beliefs, acceptability of trial participation, risks to subjects, and community repercussions. Concerns identified included the potential negative effect on breast feeding promotion efforts in Haiti, the scarcity of economic means to sustain safe bottle feeding, the risk of being labeled HIV-positive by virtue of study participation, the potential for the HIVIG trial to reinforce the misconception that a vaccine effective against AIDS exists, and problems explaining the concept of a double-blind study and accepting random assignment to treatment and control groups. As a result of these studies, it was decided to conduct the infant feeding study in a community with higher rates of exclusive bottle feeding and lower infant mortality than exist in Cite Soleil. The HIVIG trial could be conducted, but only after extensive community education to ensure informed consent. An objective assessment of subject comprehension was developed for this purpose.
Assuntos
Ensaios Clínicos como Assunto/normas , Infecções por HIV/transmissão , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez , Populações Vulneráveis , Alimentação com Mamadeira , Aleitamento Materno/efeitos adversos , Pré-Escolar , Compreensão , Grupos Controle , Características Culturais , Método Duplo-Cego , Ética Médica , Estudos de Viabilidade , Feminino , Grupos Focais , Infecções por HIV/prevenção & controle , Haiti , Humanos , Imunoglobulinas Intravenosas , Lactente , Recém-Nascido , Entrevistas como Assunto , Gravidez , Medição de RiscoRESUMO
Individual interviews were conducted with 379 youth who work and/or live on the streets of a large Brazilian city to assess HIV-related knowledge, sources of information, risk behaviors, and prevention beliefs and strategies. Respondents demonstrated high levels of factual knowledge about HIV transmission (84% correct) coupled with high levels of misconceptions about casual transmission (53% correct) and intermediate levels of knowledge about prevention (64% correct). Only 54% of the respondents had heard about AIDS recently, and 37.5% said they talked to someone about AIDS. The most common sources of information about HIV/AIDS were the mass-media and friends. Over half the sample reported taking precautions to reduce their risk of HIV infection; however, the proportion of youth taking effective precautions was low. Among the 247 youth (65% of the sample) who had initiated sexual activity, lifetime condom use was reported by 18%, and condom use at last intercourse by 10%. Youth with higher levels of knowledge were more likely to report behavior changes to avoid HIV infection. These findings underscore the urgent need for prevention programs tailored to street youth in developing countries.
Assuntos
Países em Desenvolvimento , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Jovens em Situação de Rua/psicologia , População Urbana , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Síndrome da Imunodeficiência Adquirida/psicologia , Síndrome da Imunodeficiência Adquirida/transmissão , Adolescente , Brasil , Criança , Preservativos , Feminino , Infecções por HIV/psicologia , Infecções por HIV/transmissão , Comportamentos Relacionados com a Saúde , Educação em Saúde , Humanos , Masculino , Trabalho SexualRESUMO
Social networks and daily activities of children and adolescents living and/or working on the streets of a large Brazilian city were examined. Drawing on data collected through structured surveys, in-depth interviews, focus group discussions, and field observations, we described street youths' family situation, social resources, institutional experiences, survival activities, and problem behaviors and investigated differences attributable to age, gender, and living situation (at home or on the street). Youngsters who lived at home and worked on the street appeared to be experiencing orderly development despite their impoverished circumstances. Youngsters who lived on the street showed hallmarks of psychological and physical risk, including parental loss, diminished social support, substance abuse, and early onset of sexual activity. Possible implications of these contextual differences for development are discussed, and directions for future research are suggested.
Assuntos
Atividades Cotidianas/psicologia , Países em Desenvolvimento , Pessoas Mal Alojadas/psicologia , Desenvolvimento da Personalidade , Pobreza , Apoio Social , População Urbana , Adolescente , Brasil , Criança , Crime/prevenção & controle , Crime/psicologia , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Humanos , Masculino , Meio SocialRESUMO
METHODS: From June 1989 to April 1991, 394 adolescents aged 10-18 years randomly selected upon admission at a state shelter in Belo Horizonte, Brazil underwent health history interview, physical examination, serology for HIV, hepatitis B, and syphilis, and stool examination. Participants were classified as street-based youths (n = 195) or home-based youths (n = 199). The age distribution was similar in both groups, although males were overrepresented among street-based youths (79.5% versus 62.3%). RESULTS: Compared with home-based youths, street-based youths reported earlier onset (p = 0.009) and higher rates of sexual activity (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.4-3.3), sexual abuse (OR, 3.7; 95% CI, 1.2-10.1), and sexually transmitted diseases (OR, 2.9; 95% CI, 1.3-6.6). Overall condom use was low in both groups. Street-based youths were 7.8 times more likely to use drugs than home-based youths (95% CI, 4.9-12.7). Inhalants and marijuana were the more commonly used drugs. Intravenous drug use was low. CONCLUSIONS: Although chronic malnutrition and multiple parasitosis were common findings in both groups, street-based youths were more likely to present disorders related to trauma and poor hygienic conditions. Antibodies to HIV were detected in four (2%) street-based youths and in none of the home-based youths. This study confirms that street youths are at higher risk for HIV infection than their home-based peers and indicates a need for HIV prevention programs targeting this population.
Assuntos
Comportamento do Adolescente , Infecções por HIV/epidemiologia , Comportamentos Relacionados com a Saúde , Nível de Saúde , Pessoas Mal Alojadas , Pobreza , Assunção de Riscos , Adolescente , Distribuição por Idade , Brasil/epidemiologia , Criança , Intervalos de Confiança , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Necessidades e Demandas de Serviços de Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Morbidade , Razão de Chances , Fatores de RiscoRESUMO
OBJECTIVE: To determine whether deaths among Haitian infants born to HIV-1-seronegative women could be distinguished from deaths among children born to HIV-1-seropositive women using the verbal autopsy technique. METHODS: Mothers of 315 Haitian children who died were interviewed about events leading to the child's death. Three physicians independently reviewed interview data and determined the probable cause of death without knowledge of maternal HIV-1 status or hospital records. The underlying causes of death assigned to the infants were analyzed to determine whether maternal HIV status could be predicted. RESULTS: There was good agreement among the physicians (kappa = 0.62) and 90% agreement between hospital records and the verbal autopsy diagnosis. Compared with children born to HIV-1-seronegative women, deaths in children born to HIV-1-seropositive mothers were more likely to be ascribed to a presumptive diagnosis of AIDS (37 versus 21%; P = 0.01). The sensitivity and specificity of verbal autopsies for identifying deaths associated with maternal HIV-1 infection ranged from 37 to 59% and from 69 to 79%, respectively, depending on the classification system used. The predictive positive value of a death believed to be consistent with pediatric HIV-1 infection was 26-30% and the predictive negative value was 85-90%. CONCLUSION: Verbal autopsies may be useful for distinguishing certain causes of death, but have limited utility for distinguishing deaths associated with maternal HIV-1 infection from deaths among children born to HIV-1-seronegative women.
Assuntos
Síndrome da Imunodeficiência Adquirida/mortalidade , Síndrome da Imunodeficiência Adquirida/patologia , Autopsia/métodos , Causas de Morte , Pré-Escolar , Feminino , Soropositividade para HIV , Haiti/epidemiologia , Humanos , Lactente , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Sensibilidade e EspecificidadeRESUMO
This study evaluated the safety, tolerability, and pharmacokinetics of zidovudine administered intravenously and orally to infants born to women infected with the human immunodeficiency virus. Thirty-two symptom-free infants were enrolled before 3 months of age. The pharmacokinetics of zidovudine were evaluated in each infant after single intravenously and orally administered doses of zidovudine on consecutive days, and during long-term oral administration of the drug for 4 to 6 weeks. As new patients were enrolled, doses of zidovudine were progressively increased from 2 to 4 mg/kg. Therapy was continued for up to 12 months in 7 of the infants proved to be infected with human immunodeficiency virus. Zidovudine was generally well tolerated; 20 children (62.5%) had anemia (hemoglobin level < 10.0 gm/dl) during therapy and 9 (28.1%) had neutropenia (neutrophil count < or = 750 cells/mm3); these hematologic abnormalities usually resolved spontaneously. The total body clearance of zidovudine increased significantly with age, from an average of 10.9 ml/min per kilogram in infants < or = 14 days of age to 19.0 ml/min per kilogram in older infants (p < 0.0001). Concurrently, there was a significant decrease in serum half-life from 3.12 hours in infants < or = 14 days to 1.87 hours in older infants (p = 0.0002). Oral absorption was satisfactory and bioavailability decreased significantly with age, from 89% in infants < or = 14 days to 61% in those > 14 days of age (p = 0.0002). Plasma concentrations of zidovudine were calculated to be in excess of 1 mumol/L (0.267 micrograms/ml) for 4.12 +/- 1.86 hours and 2.25 +/- 0.78 hours after oral doses of 2 mg/kg in infants younger than 2 weeks and 3 mg/kg in older infants, respectively. We conclude that zidovudine administered at oral doses of 2 mg/kg every 6 hours to infants aged less than 2 weeks and 3 mg/kg every 6 hours to infants older than 2 weeks resulted in plasma concentrations that are considered virustatic against human immunodeficiency virus. Zidovudine was well tolerated by infants at these doses.
Assuntos
Infecções por HIV/congênito , Infecções por HIV/tratamento farmacológico , Troca Materno-Fetal , Zidovudina/uso terapêutico , Administração Oral , Anemia/induzido quimicamente , Esquema de Medicação , Tolerância a Medicamentos , Feminino , Infecções por HIV/transmissão , Humanos , Lactente , Recém-Nascido , Infusões Intravenosas , Masculino , Gravidez , Complicações Infecciosas na Gravidez , Zidovudina/administração & dosagem , Zidovudina/efeitos adversos , Zidovudina/análogos & derivados , Zidovudina/sangue , Zidovudina/metabolismo , Zidovudina/farmacocinéticaRESUMO
Antibodies to herpes simplex virus type 2 (HSV-2), antibodies to hepatitis B virus (HBV) core antigen (anti-HBc), and VDRL antibodies (serologic evidence of syphilis) were evaluated in women known to be infected with human immunodeficiency virus type 1 (HIV-1) (n = 95) or human T lymphotropic virus type I (HTLV-I) (n = 45) and controls (n = 89). HIV-1-seropositive women were more likely than controls to have antibodies to HSV-2 (88% vs. 54%; P less than .001), anti-HBc (67% vs. 43%; P = .008), and VDRL antibodies (21% vs. 8%; P = .02). Similarly, HTLV-I-seropositive women were more likely than controls to have antibodies to HSV-2 (82% vs. 54%; P = .003) and anti-HBc (67% vs. 43%; P = .008). There was no evidence that HIV-1 or HTLV-I predisposed to chronic hepatitis B virus infection. The stronger associations between HIV-1 and HTLV-I with HSV-2 than the associations with syphilis or HBV are consistent with the hypothesis that recurrent disruptions of mucous membranes caused by HSV-2 infections predispose to sexual transmission of HIV-1 and HTLV-I.
Assuntos
Infecções por HIV/complicações , Infecções por HTLV-I/complicações , Hepatite B/epidemiologia , Herpes Simples/epidemiologia , Sífilis/epidemiologia , Adolescente , Adulto , Fatores Etários , Anticorpos Antivirais/sangue , Feminino , Anticorpos Anti-HIV/sangue , HIV-1 , Anticorpos Anti-HTLV-I/sangue , Haiti/epidemiologia , Hepatite B/complicações , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Herpes Simples/complicações , Humanos , Prevalência , Simplexvirus/imunologia , Sífilis/complicações , Sorodiagnóstico da SífilisRESUMO
Of 4588 pregnant women in a high-risk Haitian population, 443 (9.7%) were serologically positive for the human immunodeficiency virus type 1 (HIV-1). Infants born to women who were HIV-1 seropositive were more likely to be premature, of low birth weight, and malnourished at 3 and 6 months of age than were infants born to women who were HIV-1 seronegative. Increased mortality was observed in infants born to women who were HIV-1 seropositive by 3 months of age. At 12 months of age, 23.4% of the infants born to women who were HIV-1 seropositive had died compared with 10.8% of the infants born to women who were HIV-1 seronegative; at 24 months of age, the mortality rates were 31.3% and 14.2%, respectively. Maternal HIV-1 infections resulted in an 11.7% increase in the overall infant mortality rate in this population. The estimated mother-to-infant HIV-1 transmission rate in these breast-fed infants was 25%, similar to the rates reported for non-breast-fed populations in the United States and Europe.
Assuntos
Infecções por HIV/transmissão , HIV-1 , Mortalidade Infantil , Transtornos da Nutrição do Lactente/epidemiologia , Adulto , Peso ao Nascer , Pré-Escolar , Países em Desenvolvimento , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/mortalidade , Soropositividade para HIV/epidemiologia , Haiti/epidemiologia , Humanos , Lactente , Transtornos da Nutrição do Lactente/mortalidade , Recém-Nascido , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/mortalidade , Masculino , Avaliação Nutricional , Gravidez , Complicações Infecciosas na Gravidez/epidemiologiaRESUMO
Pregnant Haitian women (n = 4,474) residing in a periurban slum were interviewed to identify risk factors for sexually transmitted diseases and sera were tested to identify antibodies to HIV-1 and syphilis. The seroprevalence rates for antibodies to HIV-1 increased from 8.9% in 1986 to 9.9% in 1987 and 10.3% in 1988. Sera obtained in 1982 from 533 mothers of young infants in the same community revealed that 7.8% were HIV-1 seropositive. Of women pregnant for the first time in 1986-1988, 6.6% were HIV-1 seropositive and 6.0% had a positive VDRL. The highest seropositivity rates (greater than 15%) were noted in women 20 to 29 years of age with a history of two or more sexual partners in the year prior to pregnancy. Factors independently associated with HIV-1 seropositivity in pregnant women by logistic regression analysis included being unmarried, age 20-29 years, having had more than one sex partner in the year prior to pregnancy, a positive serologic test for syphilis, and smoking. A dose-response effect was noted in the association between HIV-1 seropositivity and smoking. The association between smoking and HIV-1 infections could be confounded by unrecognized behavioral factors or due to a biologic effect of smoking. The continuing high HIV-1 seropositivity rates in pregnant women indicate that current preventive measures are insufficient and increased control efforts are urgently needed.
Assuntos
Soroprevalência de HIV , Complicações Infecciosas na Gravidez/epidemiologia , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Haiti/epidemiologia , Humanos , Casamento , Pobreza , Gravidez , Análise de Regressão , Estudos Retrospectivos , Fatores de Risco , Parceiros Sexuais , Fumar , Sífilis/complicações , Sífilis/epidemiologia , Sorodiagnóstico da Sífilis , População UrbanaRESUMO
Patent infections with the lymphatic filariae, Wuchereria bancrofti and Brugia malayi, are associated with suppressed in vitro cellular responsiveness to filarial antigens. In studies of bancroftian filariasis in Haiti, a significant number of microfilaremic individuals can be characterized as "responders" to filarial antigens. Cells from 37/74 untreated microfilaremic subjects responded to B. pahangi antigen (stimulation ratio greater than 2) as detected by in vitro blastogenesis. A comparison of responders to nonresponders revealed a significant difference in mean B. pahangi reactivity (15,822 vs. 4,538 cpm, P less than 0.001), but no significant differences with respect to age, microfilaremia, PPD or PHA reactivity, or B. pahangi-specific antibody levels. Subtle differences may exist between these groups with respect to recognition of specific antigens on Western blots.