Paula Dias Bevilacqua

Reflexões sobre a qualidade do diagnóstico da leishmaniose visceral canina em inquéritos epidemiológicos: o caso da epidemia de Belo Horizonte, Minas Gerais, Brasil, 1993-1997

In Brazil, visceral leishmaniasis poses a serious endemic and epidemic problem. In recent years the disease has spread to several States that had not previously reported any human or animal cases. For canine surveys, the Ministry of Health currently recommends use of the indirect immunofluorescence assay (IIF), with a sensitivity of 90-100% and specificity of 80%. Use of IIF may decrease the effectiveness of the Kala Azar Control Program by not detecting, and thus failing to sacrifice, false-negative infected animals. On the other hand, the program incorrectly identifies and leads to the unwarranted sacrifice of false-positive uninfected animals. Such uncertainties have already led to disagreement over the Programs objectives, such as the recommendation by some veterinarians that infected animals be treated. This work analyzes the quality of diagnosis of canine epidemic surveys against the backdrop of a visceral leishmaniasis epidemic in Belo Horizonte, Minas Gerais State, from 1993 to 1997.

Urbanização da leishmaniose visceral em Belo Horizonte

O Brasil vivencia na atualidade uma situacao na qual velhas endemias, que se pensava esquecidas, ressurgem com grande impacto e muitas vezes com perfis de morbi-mortalidades diferentes daqueles ja conhecidos. Este e o caso da leishmaniose visceral, uma doenca caracteristicamente rural e associada a condicoes precarias de vida, que encontra no espaco urbano ambiente favoravel para se estabelecer e desenvolver. O municipio de Belo Horizonte convive, desde 1993, com uma epidemia de calazar humano e canino. Foram feitas a reconstrucao historica da enfermidade e a caracterizacao de alguns aspectos demograficos dos casos humanos. Aparentemente a doenca foi introduzida em Belo Horizonte a partir de focos existentes em municipios vizinhos, como Sabara. Os Distritos Sanitarios Leste e Nordeste foram os mais acometidos. A evolucao espacial da epidemia mostrou que os casos caninos precederam os humanos, confirmando a importância do cao como reservatorio do calazar em areas urbanas. O risco de adoecer foi maior em criancas menores de 15 anos. A situacao de Belo Horizonte ilustra muito bem o processo de urbanizacao de enfermidades tradicionalmente rurais, vivenciado por varias cidades brasileiras.

Aspectos demográficos e espaciais dos acidentes escorpiônicos no Distrito Sanitário Noroeste, Município de Belo Horizonte, Minas Gerais, 1993 a 1996

This paper analyzes a total of 352 scorpion sting reports in the Northwest quarter of Belo Horizonte, Minas Gerais. Traditionally, this area has shown one of the highest case incidence rates, and the present study pointed to 10.37 stings per 10,000 inhabitants. No gender preference was observed, but most victims were 50 years of age or older. Likewise, no relationship was observed between seasonality and sting rates. According to geographic distribution analyses, the highest incidence rates were in areas with the largest scorpion populations. This preliminary descriptive evaluation is important for guidelines to prevent scorpion stings, which should obviously consider local epidemiological features.

Isolamento de Salmonella sp e Staphylococcus aureus no processo do abate suíno como subsídio ao sistema de Análise de Perigos e Pontos Críticos de Controle - APPCC

O presente estudo foi realizado para avaliar a presenca de Salmonella sp e o numero de Staphylococcus aureus na superficie de carcacas suinas e caracterizar os perigos microbiologicos em diferentes etapas do abate e pontos criticos de controle (PCCs), atraves da quantificacao de riscos (odds ratio). Um total de 120 esfregacos superficiais de carcaca suina foi coletado em um matadouro-frigorifico, apos o escaldamento/depilacao (ponto A), antes da evisceracao (B), apos evisceracao e serragem da carcaca (C) e apos 24 horas de refrigeracao (D). Salmonella sp foi encontrada com uma frequencia media de 11,7% (14) nas carcacas, enquanto o numero de S. aureus variou entre 1,2 e 1,5 log UFC/cm2 em 11,7% das carcacas amostradas, sem evidenciar diferenca estatistica entre os pontos A, B, C e D. Pode-se concluir que os riscos de contaminacao por Salmonella sp e S. aureus foram os mesmos nas etapas do abate de suinos consideradas neste estudo.

Quantitative microbial risk assessment applied to irrigation of salad crops with waste stabilization pond effluents.

A quantitative microbial risk assessment model for estimating infection risks arising from consuming crops eaten raw that have been irrigated with effluents from stabilization ponds was constructed. A log-normal probability distribution function was fitted to a large database from a comprehensive monitoring of an experimental pond system to account for variability in Escherichia coli concentration in irrigation water. Crop contamination levels were estimated using predictive models derived from field experiments involving the irrigation of several crops with different effluent qualities. Data on daily intake of salad crops were obtained from a national survey in Brazil. Ten thousand-trial Monte Carlo simulations were used to estimate human health risks associated with the use of wastewater for irrigating low- and high-growing crops. The use of effluents containing 10(3)-10(4) E. coli per 100 ml resulted in median rotavirus infection risk of approximately 10(-3) and 10(-4) pppy when irrigating, respectively, low- and high-growing crops; the corresponding 95th percentile risk estimates were around 10(-2) in both scenarios. Sensitivity analyses revealed that variations in effluent quality, in the assumed ratios of pathogens to E. coli, and in the reduction of pathogens between harvest and consumption had great impact upon risk estimates.

Wastewater irrigation of salad crops: further evidence for the evaluation of the WHO guidelines.

This paper presents the results of an experiment on salad crop irrigation with waste stabilisation pond effluents, conducted in Southeast Brazil. Over about 18 months several trials were carried out using different effluent qualities to irrigate lettuce, kale, arugula, spinach, and green pepper. Equations for predicting the bacterial quality of irrigated crops (E.coli per gram) based on the irrigation water quality (E.coli per 100 mL) were derived for low and high growing crops. The quantitative microbial risk analysis (QMRA) technique, using pathogen-ingestion scenarios based on these field data and on official statistics of vegetables consumption in Brazil, was used to estimate infection risks arising from the consumption of wastewater irrigated crops. It is inferred that irrigation with effluents complying with the WHO guidelines for unrestricted irrigation should result in salad crops acceptable for consumption.

Post-treatment of UASB reactor effluent in waste stabilization ponds and in horizontal flow constructed wetlands: a comparative study in pilot scale in Southeast Brazil.

The results of a 20-month period study in Brazil were analyzed to compare horizontal-flow constructed wetlands (CW) and waste stabilization pond (WSP) systems in terms of land area requirements and performance to produce effluent qualities for surface water discharge, and for wastewater use in agriculture and/or aquaculture. Nitrogen, E. coli and helminth eggs were more effectively removed in WSP than in CW. It is indicated that CW and WSP require similar land areas to achieve a bacteriological effluent quality suitable for unrestricted irrigation (10(3) E. coli per 100 mL), but CW would require 2.6 times more land area than ponds to achieve quite relaxed ammonia effluent discharge standards (20 mg NH(3) L(-1)), and, by far, more land than WSP to produce an effluent complying with the WHO helminth guideline for agricultural use (< or =1 egg per litre).

Análise e monitoramento de pontos críticos no abate de frangos utilizando indicadores microbiológicos

Hygiene indicator microorganisms in a poultry slaughter was evaluated during the processing in order to identify potential critical control points and allow options for monitoring or verification by Hazard Analysis Critical Control Point (HACCP) system. Microbiological superficial contamination of chicken carcasses was establish by the enumeration of mesophilic aerobes, total coliforms, thermotolerant coliforms and Escherichia coli in the following steps of processing: A - before the first hygienic shower, B - after the first hygienic shower, C - after manual evisceration, D - after final washing shower, and E - after the chiller tank. The mean counts of mesophilic aerobes, total and thermotolerant coliforms was not significantly different (P<0.05) in the steps A, B, C and D. However, the mean values of these microorganisms in step E (after chilling) was significantly lower when compared to the one obtained in the other steps. The mean counts of Escherichia coli were not significantly different, independently of the processing step analyzed. The chances of contamination were estimated by Odds Ration, and it was observed that chances were higher in the step A for mesophilic aerobes, and in the step C for coliforms. Considering the analyzed parameters, the levels of contamination by mesophilic aerobes, total and thermotolerant coliforms were the most suitable for monitoring and verification of a HACCP system in a poultry processing plant. The obtained results indicate that the chilling can be considered as an important critical control point, once this procedure was able to reduce significantly the microbiological contamination.

Vigilância da qualidade da água para consumo humano: abordagem qualitativa da identificação de perigos

A necessidade de que os servicos de vigilância da qualidade da agua para consumo realizem sistematica/permanente avaliacao de risco dos sistemas de abastecimento e um importante desafio. Como a metodologia de Avaliacao de Risco ainda nao se encontra estruturada para rotineira utilizacao, apresenta-se uma sugestao de identificacao de perigos e categorizacao de riscos associados ao abastecimento de agua, atraves da utilizacao da metodologia proposta no Manual de Procedimentos de Vigilância em Saude Ambiental Relacionada a Qualidade da Agua para Consumo Humano, com modificacoes. Foram identificadas situacoes de perigo na saida do tratamento e na rede de distribuicao do sistema estudado. A aplicacao da metodologia permitiu uma visao abrangente do sistema de abastecimento e informacoes para planejamento/priorizacao de medidas de forma a reduzir os perigos identificados e possiveis riscos a saude da populacao.

Phlebotomine fauna in the urban area of Timóteo, State of Minas Gerais, Brazil

This work is characterized by an entomological research and an investigation on whether seasonal behaviours can be associated to the phlebotomine fauna found in the urban area of Timóteo-MG - an endemic focus of tegumentary leishmaniasis (TL). The analysis of the seasonal behaviour of sand flies has taken into account the following climatic variables: rainfall, relative humidity and temperature. Automatic light traps were installed in households between 2009 and 2010. The sand fly species with the highest number captured was Lutzomyia whitmani (66.5%), a TL vector species, whose abundance has provided strong evidences that this species is the main vector of TL in the municipality of Timóteo, with its cycle of transmission developing in its urban area. Amongst the results observed in the analyses of seasonal behaviour, only temperature conveyed particular association between seasonal occurrence of sand flies and climate variables. The findings of this study may assist the local epidemiological surveillance agency in defining strategies and directing efforts for controlling these insects.