Abstract in English:The human bartonelloses are a group of diseases with a rapidly increasing clinical spectrum. Well known manifestations such as Carrion's disease, trench fever, cat-scratch disease, and bacillary angiomatosis are examples of Bartonella spp. infection. Along with these diseases, recurrent bacteremia, endocarditis, septicemia, erythema nodosum, erythema multiforme, trombocytopenic purpura and other syndromes have been reported having been caused by bacteria of this genus. The infectious process and the pathogenesis of these microorganisms are poorly understood. The bartonelloses may have a benign and self-limited evolution in a host, or a potentially fatal one. These bacteria can provoke a granulomatous or an angioproliferative histopathologic response. As these diseases are not yet well defined, we have reviewed the four main human bartonelloses and have examined unclear points about these emergent diseases.
Abstract in English:Human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) are the causative agents of AIDS. HIV-2 is prevalent at moderate to high rates in West African countries, such as Senegal, Guinea, Gambia, and Cape Verde. Diagnosis of HIV-2 is made with a positive HIV-1/HIV-2 ELISA or simple/rapid assay, followed by one or two confirmatory tests specific for HIV-2. Following CD4+ T cell counts, HIV-2 viral burden and clinical signs and symptoms of immunodeficiency are beneficial in monitoring HIV-2 disease progression. Although non-nucleoside reverse transcriptase inhibitors are ineffective in treating HIV-2, nucleoside reverse transcriptase inhibitors and protease inhibitors can be effective in dual and triple antiretroviral regimens. Their use can decrease HIV-2 viral load, increase CD4+ T cell counts and improve AIDS-related symptoms. HIV-2 resistance to various nucleoside reverse transcriptase inhibitors and protease inhibitors, including zidovudine, lamivudine, ritonavir and indinavir, has been identified in some HIV-2 infected patients on antiretroviral therapy. The knowledge of HIV-2 peculiarities, when compared to HIV-1, is crucial to helping diagnose and guide the clinician in the choice of the initial antiretroviral regimen and for monitoring therapy success.
Abstract in English:Advanced HIV infection is frequently complicated by diarrhea, disruption of bowel structure and function, and malnutrition. Resulting malabsorption of or pharmacokinetic changes in antiretroviral agents might lead to subtherapeutic drug dosing and treatment failure in individual patients, and could require dose adjustment and/or dietary supplements during periods of diarrheal illness. We determined the plasma levels of antiretroviral medications in patients that had already been started on medication by their physicians in an urban infectious diseases hospital in northeast Brazil. We also obtained blood samples from patients hospitalized for diarrhea or AIDS-associated wasting, and we found reduced stavudine and didanosine levels in comparison with outpatients without diarrhea or wasting who had been treated at the same hospital clinic. There was a predominance of the protozoal pathogens Cryptosporidium and Isospora belli, typical opportunistic pathogens of AIDS-infected humans, in the stool samples of inpatients with diarrhea. We conclude that severe diarrhea and wasting in this population is associated with both protozoal pathogens and subtherapeutic levels of antiretroviral medications.
Abstract in English:The success of pathogenic microbes depends on their ability to colonize host tissues and to counter host defense mechanisms. Microorganisms can produce overwhelming infection because of their relatively short generation times, and because they have evolved powerful mechanisms for generating phenotypic diversity as an efficient strategy for adapting to rapidly responding immune system defenses and the broad range of polymorphisms characteristic of different host tissues. Bacterial evolution may not be a continuous process, but more of a succession of temporally spaced major events. These events cause a non-gradual sequence of adaptations to a given environment. The pathogenicity islands may be genetically unstable elements, and many of the genes coding for the adhesins, toxins and other virulence factors are present in pathogenicity islands, which almost certainly had former lives as accessory elements or as parts thereof, or were borne on functional accessory elements. Novel genes are also acquired by transduction (mediated by bacteriophages, plasmids or transposons), by conjugation (DNA transfer between cells) or by transformation (natural DNA uptake). Horizontal gene transfer from other species is a major source of variation and is fundamental to the genetic theory of adaptive evolution in prokaryotes.
Abstract in English:Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially as to therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA) as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE), techniques involving polymerase chain reaction and multilocus sequence typing (MLST). Repetitive DNA Sequence PCR (rep-PCR) may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE) still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST), are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose.
Abstract in English:PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced b-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced b-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.
Abstract in English:We made an open label, multicenter, non-comparative study to assess the efficacy and safety of oral gatifloxacin, 400mg PO given once-daily during 7 to 14 days for the treatment of adult outpatients with community-acquired pneumonia at five Brazilian medical facilities. Among the 86 subjects available for clinical evaluation, 84 (98%) were cured. The bacteriological eradication and presumed eradication rate was 98% (52/53) among the 44 (51%) patients who were bacteriologically evaluated. Drug-related adverse events were reported by 27% of the patients, diarrhea being the most frequent, occurring in 12% of patients. Adverse events were considered mild (89%) or moderate (11%). We conclude that a 7-14 day course of gatifloxacin, 400mg PO given once daily is safe and effective for the treatment of community-acquired pneumonia. The drug had a favorable safety profile and a good clinical and bacteriological efficacy.
Abstract in English:INTRODUCTION: Recurrent respiratory infections account for most of the morbidity and mortality of cystic fibrosis patients. MATERIALS AND METHODS: The objective was to determine the prevalence of pathogens isolated from lower respiratory tract secretions in cystic fibrosis patients. In this descriptive observational study, data from 69 patients was collected from medical records. RESULTS: The microorganisms that were identified included 36.2% P. aeruginosa, 28.9% S. Aureus, 4.3% K. pneumoniae, 1.5% H. influenzae, 1.5% E. coli, 1.5% S. maltoophilia, and in 27.5% the flora was normal. The prevalence of P. aeruginosa was 83% in patients under two years of age, demonstrating early colonization. CONCLUSION: P. aeruginosa and S. aureus were the most prevalent pathogens; there was also early infection/colonization by P. aeruginosa. This information will contribute to improved therapeutic measures for patients of the Bahia Cystic Fibrosis Reference Center.
Abstract in English:We reviewed the clinical and radiological characteristics of tuberculosis (TB) in children and adolescents at the Hospital Especializado Octávio Mangabeira, (HEOM) in Salvador, Bahia. This study included 275 TB patients aged 1 to 15 years seen between January 1990 and November 2001. Standardized forms were filled out on the basis of a review of patient records and x-rays. Through a retrospective and descriptive analysis, it was found that 51.6% were male, 35.3% were aged 1 to 5 years, 28% were aged 6 to 10 and 36.7% were aged 11 to 15. Among all patients, 79.6% lived in the city of Salvador. A history of contact with TB was found in 63.9%, most frequently among children under 5 years old; 77.2% were vaccinated with Bacillus Calmette-Guerin (BCG). The most frequently observed symptoms were coughing (76%), fever (73.1%) weight loss (53.1%), and 4.7% were asymptomatic. Pulmonary TB was most frequent (57.8%) and extra-pulmonary TB occurred in 24.4%, with a predominance of hilar adenopathy. Both forms occurred simultaneously in 17.8%. In 53.1% of the cases the diagnosis was not determined by bacteriology or pathological anatomy; in these cases diagnosis was reached through clinical and radiological criteria, contact history, a tuberculin test >10mm and a positive response to tuberculostatic drugs.
Abstract in English:We question the movement towards exclusion of population and social health research from the field of science. The background under analysis is contemporary Brazil, where the scientific field that hosts this kind of research is known as Collective Health. First, the problem is formalized on logical grounds, evaluating the pertinence of considering unscientific the many objects and methods of public health research. Secondly, the cases of pulmonary tuberculosis and external causes are brought in as illustrations of the kind of scientific problem faced in health research today. The logical and epistemological basis of different forms of "scientific segregation" based on biomedical reductionism is analyzed, departing from three theses: (i) the ethics of the general application of science; (ii) the inappropriateness of monopolies for objectivity in the sciences; (iii) the specificity of scientific fields. In the current panorama of health research in Brazil, a residual hegemonic position that defends a narrow and specific definition of the object of knowledge was found. The denial of validity and specificity to objects, methods and research techniques that constitute social and population research in health is linked to elements of irrationality in reductionism approaches. Nevertheless, efforts should be directed to overcome this scientific division, in order to develop a pluralist and interdisciplinary national science, committed to the health care realities of our country.