Antonio Ruffino-Netto

The resumption of consumption - : A review on tuberculosis

Among all infectious diseases that afflict humans, tuberculosis (TB) remains the deadliest. At present, epidemiologists estimate that one-third of the world population is infected with tubercle bacilli, which is responsible for 8 to 10 million new cases of TB and 3 million deaths annually throughout the world. Approximately 95% of new cases and 98% of deaths occur in developing nations, generally due to the few resources available to ensure proper treatment and where human immunodeficiency virus (HIV) infections are common. In 1882, Dr Robert Koch identified an acid-fast bacterium, Mycobacterium tuberculosis, as the causative agent of TB. Thirty-nine years later, BCG vaccine was introduced for human use, and became the most widely used prophylactic strategy to fight TB in the world. The discovery of the properties of first-line antimycobacterial drugs in the past century yielded effective chemotherapies, which considerably decreased TB mortality rates worldwide. The later introduction of some additional drugs to the arsenal used to treat TB seemed to provide an adequate number of effective antimicrobial agents. The modern, standard short-course therapy for TB recommended by the World Health Organization is based on a four-drug regimen that must be strictly followed to prevent drug resistance acquisition, and relies on direct observation of patient compliance to ensure effective treatment. Mycobacteria show a high degree of intrinsic resistance to most antibiotics and chemotherapeutic agents due to the low permeability of its cell wall. Nevertheless, the cell wall barrier alone cannot produce significant levels of drug resistance. M. tuberculosis mutants resistant to any single drug are naturally present in any large bacterial population, irrespective of exposure to drugs. The frequency of mutants resistant to rifampicin and isoniazid, the two principal antimycobacterial drugs currently in use, is relatively high and, therefore, the large extra-cellular population of actively metabolizing and rapidly growing tubercle bacilli in cavitary lesions will contain organisms which are resistant to a single drug. Consequently, monotherapy or improperly administered two-drug therapies will select for drug-resistant mutants that may lead to drug resistance in the entire bacterial population. Thereby, despite the availability of effective chemotherapy and the moderately protective vaccine, new anti-TB agents are urgently needed to decrease the global incidence of TB. The resumption of TB, mainly caused by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains and HIV epidemics, led to an increased need to understand the molecular mechanisms of drug action and drug resistance, which should provide significant insight into the development of newer compounds. The latter should be effective to combat both drug-susceptible and MDR/XDR-TB.

Tuberculose: a calamidade negligenciada

Epidemiological data on tuberculosis and the fight against the disease in Brazil and in the world are reviewed herein. Historical aspects of the different approaches to the control of the disease in Brazil are highlighted and the ongoing Brazilian Program for the Control of Tuberculosis is examined. To conclude, the author takes a look at unresolved problems and considers new alternatives for the control of tuberculosis.

Performance assessment questionnaire regarding TB control for use in primary health care clinics in Brazil

The objective of this study was to provide access to and disseminate a questionnaire used as an instrument to assess the organizational elements and the performance of primary health care clinics regarding TB control in Brazil, comparing selected organizational dimensions by health care clinic, by municipality and by actor (patients, health care workers and managers). The results show that municipalities where the coverage of supervised treatment was more extensive presented more favorable indicators regarding access to TB treatment. The organizational format of the health care clinics involved in TB treatment-family health programs and referral centers with specialized teams in TB Control Programs (TCPs)-was not a factor that expanded access to diagnosis. The TCPs involving a smaller number of patients presented better performance regarding health care professional-patient relationship. The majority of the patients faced economic and social difficulties, and most managers were unaware of the amount of resources allocated to TB control activities. The instrument proved to be viable and to have the potential to adequately assess the performance of health care clinics in the urban areas studied.

Predicting smear negative pulmonary tuberculosis with classification trees and logistic regression: a cross-sectional study

BackgroundSmear negative pulmonary tuberculosis (SNPT) accounts for 30% of pulmonary tuberculosis cases reported yearly in Brazil. This study aimed to develop a prediction model for SNPT for outpatients in areas with scarce resources.MethodsThe study enrolled 551 patients with clinical-radiological suspicion of SNPT, in Rio de Janeiro, Brazil. The original data was divided into two equivalent samples for generation and validation of the prediction models. Symptoms, physical signs and chest X-rays were used for constructing logistic regression and classification and regression tree models. From the logistic regression, we generated a clinical and radiological prediction score. The area under the receiver operator characteristic curve, sensitivity, and specificity were used to evaluate the models performance in both generation and validation samples.ResultsIt was possible to generate predictive models for SNPT with sensitivity ranging from 64% to 71% and specificity ranging from 58% to 76%.ConclusionThe results suggest that those models might be useful as screening tools for estimating the risk of SNPT, optimizing the utilization of more expensive tests, and avoiding costs of unnecessary anti-tuberculosis treatment. Those models might be cost-effective tools in a health care network with hierarchical distribution of scarce resources.

Aspectos epidemiológicos da co-infecção tuberculose e vírus da imunodeficiência humana em Ribeirão Preto (SP), de 1998 a 2003

OBJETIVO: O estudo teve como proposito caracterizar o perfil epidemiologico dos casos de tuberculose notificados em Ribeirao Preto (SP), no periodo de 1998 a 2003, segundo a condicao sorologica para o virus da imunodeficiencia humana, sexo, faixa etaria e resultado do tratamento. METODOS: Trata-se de uma investigacao epidemiologica de cunho descritivo, que utilizou como instrumento de coleta de dados o banco de dados do Sistema de Informacao da Tuberculose. A populacao do estudo constituiu-se na totalidade dos casos de co-infeccao tuberculose e virus da imunodeficiencia humana, de residentes em Ribeirao Preto, notificados nos anos de 1998 a 2003. RESULTADOS: Nesse periodo foram notificados 1.273 casos de tuberculose, sendo que 377 apresentaram sorologia positiva para o virus da imunodeficiencia humana, o que significou taxa de co-infeccao igual a 30%. Em relacao ao sexo, observou-se neste grupo que 76% dos casos notificados foram de homens, havendo predominância na faixa etaria de 20 a 59 anos. Quanto ao resultado terapeutico, a media de cura alcancada foi de 52%, de abandono de 11% e de obito de 32%. A forma clinica predominante foi a pulmonar, com 58% dos casos. CONCLUSAO: Foi observada alta prevalencia da co-infeccao no municipio estudado, sendo nitido que a conclusao terapeutica desses casos reflete a necessidade de se adotar estrategias especiais de acompanhamento dessa clientela. Quanto ao sexo e faixa etaria, o acometimento foi equivalente ao de casos de tuberculose nao infectados pelo virus da imunodeficiencia humana.

Avaliação do acesso às ações de controle da tuberculose no contexto das equipes de saúde da família de Bayeux - PB

A descentralizacao das acoes de controle da Tuberculose para o âmbito da Atencao Primaria a Saude (APS), vem impondo reorientacao da pratica das Equipes de Saude da Familia (ESF) e requerendo metodologias que avaliem em que medida os componentes da APS estao sendo alcancados. Este estudo toma como recorte um componente da APS-acesso, com o objetivo de avaliar as acoes de controle da Tuberculose no contexto das ESF em Bayeux-PB. Pesquisa avaliativa, de abordagem quantitativa, que envolveu 82 profissionais de saude. O instrumento utilizado continha sete perguntas fechadas, segundo possibilidades produzidas por escala intervalar tipo Likert. Os dados foram tabulados utilizando-se o programa - Statistical Package for the Social Sciences e analisados segundo frequencia e mediana. Os resultados revelaram fragilidades e potencialidades de acesso as acoes de controle da Tuberculose (TB). Quanto as potencialidades, constatou-se que a descentralizacao do tratamento dos casos de TB vem se estabelecendo na pratica das ESF: 92,7% dos entrevistados mencionaram que os doentes de TB sempre conseguem consulta nas unidades, sendo possivel para 82,9% obte-la no prazo de 24 horas; os medicamentos especificos apresentaram-se acessiveis para 64,6% das ESF. Como fragilidades, verificou-se que 61% dos entrevistados nao realizaram coleta de escarro; 54,9% das unidades nao oferecem atendimento no horario de almoco; 89,8% dos entrevistados nao contam com auxilio transporte; apenas 40,2% das unidades adotam regularmente a visitacao domiciliar. Recomenda-se a adocao de mecanismos de gestao que viabilizem a uniformizacao e utilizacao dos recursos existentes, ampliando a capacidade resolutiva das ESF, promovendo eficiencia na prestacao de servicos e assegurando o acesso da populacao.

Retardo no diagnóstico da tuberculose em município da tríplice fronteira Brasil, Paraguai e Argentina

OBJETIVO: Identificar os aspectos relacionados aos doentes e aos servicos de saude no retardo do diagnostico da tuberculose. METODOS: Estudo epidemiologico em Foz do Iguacu, Parana, Brasil, realizado em 2009. Utilizou-se o instrumento The Primary Care Assessment Tool adaptado para a avaliacao da atencao a tuberculose. Empregaram-se tambem tecnicas de estatistica descritiva, como analise de frequencia, medidas de posicao (mediana e intervalos interquartis) e odds. RESULTADOS: Houve retardo na busca por servicos de saude entre aqueles na faixa etaria > 60 anos, sexo feminino, baixa escolaridade e conhecimento precario sobre a doenca. As variaveis clinicas caso novo e infeccao por HIV e as variaveis comportamentais uso de cigarros e bebidas alcoolicas nao estiveram relacionadas ao retardo no diagnostico. O tempo para o diagnostico atribuido ao doente e ao servico de saude foi de 30 e 10 dias (mediana), respectivamente. O Pronto Atendimento 24 Horas e a Atencao Primaria a Saude nao foram efetivos para a suspeicao de tuberculose e solicitacao de exames de apoio diagnostico, com alto percentual de encaminhamento para o ambulatorio do Programa de Controle da Tuberculose. CONCLUSOES: A procura pela Atencao Primaria a Saude para o diagnostico resultou em maior tempo ate a descoberta da doenca. O ambulatorio do Programa de Controle da Tubercu lose apresentou desempenho mais efetivo para o diagnostico da tuberculose devido ao preparo da equipe e ao acolhimento ordenado com oferta de exames de apoio diagnostico.

Dengue em localidade urbana da região sudeste do Brasil: aspectos epidemiológicos

A dengue fever epidemic which occurred in Ribeirao Preto County, S. Paulo State, Brazil, during the period November, 1990 to March, 1991 has been analysed else where. The general aspects of dengue epidemiology and control have been reviewed in this article. Emphasis is given to the analysis of some factors involved in the risk of dengue haemorrhagic fever and ecological aspects of the vector, as well as to the appropriateness of strategies for dengue eradication or control. Epidemiological characteristics of dengue, mainly those related to its occurrence in different geographical areas and periods of time are described. The Ribeirao Preto epidemic has thus, been set within the context of the spread of the disease at global level, in the Americas, and particularly in Brazil and S. Paulo State.

Perfil de resistência de Mycobacterium tuberculosis no estado de Mato Grosso do Sul, 2000-2006

OBJECTIVE To determine the drug resistance profile of Mycobacterium tuberculosis in the state of Mato Grosso do Sul, Brazil, between 2000 and 2006. METHODS Descriptive study of reported tuberculosis cases in the Brazilian Case Registry Database. We included only those cases in which M. tuberculosis culture was positive and sensitivity to drugs (rifampicin, isoniazid, streptomycin and ethambutol) was tested. Löwenstein-Jensen and Ogawa-Kudoh solid media were used for cultures, as was an automated liquid medium system. Sensitivity tests were based on the proportion method. RESULTS Among the 783 cases evaluated, males predominated (69.7%), as did patients in the 20-49 year age bracket (70%), a diagnosis of pulmonary tuberculosis (94.4%) and positive HIV serology (8.6%); 645 (82.4%) were new cases, and 138 (17.6%) had previously been treated. Resistance to at least one drug was found in 143 cases (18.3%). The primary resistance (PR) rate was, respectively, 8.1%, 1.6%, 2.8% and 12.4%, for monoresistance, multidrug resistance (MDR), other patterns of resistance and resistance to at least one drug, whereas the acquired resistance (AR) rate was 14.5%, 20.3%, 10.9% and 45.7%, respectively, and the combined resistance (CR) rate was 9.2%, 4.9%, 4.2% and 18.3%, respectively. In PR, streptomycin was the most common drug, whereas isoniazid was the most common in AR and CR (7.2% and 3.7%, respectively). CONCLUSIONS These high levels of resistance undermine the efforts for tuberculosis control in Mato Grosso do Sul. Acquired MDR was 12.7 times more common than was primary MDR, demonstrating that the previous use of drug therapy is an indicator of resistance. These levels reflect the poor quality of the health care provided to these patients, showing the importance of using the directly observed treatment, short course strategy, as well as the need to perform cultures and sensitivity tests for the early diagnosis of drug resistance.

Administrative measures for preventing Mycobacterium tuberculosis infection among healthcare workers in a teaching hospital in Rio de Janeiro, Brazil

Tuberculosis (TB) is an occupational disease of healthcare workers (HCWs). Administrative and engineering interventions simultaneously implemented in hospitals of developed countries have reduced the risk of nosocomial transmission of M. tuberculosis. We studied the impact of administrative infection control measures on the risk for latent TB infection (LTBI) among HCWs in a resource-limited, high-burden country. An intervention study was undertaken in a university-affiliated, inner-city hospital in Rio de Janeiro, where routine serial tuberculin skin testing (TST) is offered to all HCWs. From October 1998 to February 2001, the following infection control measures were progressively implemented: isolation of TB suspects and confirmed TB inpatients, quick turnaround for acid-fast bacilli sputum tests and HCW education in use of protective respirators. Among 1336 initially tested HCWs, 599 were retested. The number of TST conversions per 1000 person-months during and after the implementation of these measures was reduced from 5.8/1000 to 3.7/1000 person-months (P=0.006). The most significant reductions were observed in the intensive care unit (from 20.2 to 4.5, P<0.001) and clinical wards (from 10.3 to 6.0, P<0.001). Physicians and nurses had the highest reductions (from 7.6 to 0, P<0.001; from 9.9 to 5.8, P=0.001, respectively). We conclude that administrative measures for infection control can significantly reduce LTBI among HCWs in high-burden countries and should be implemented even when resources are not available for engineering infection control measures.