Health technology diffusion in developing countries: a case study of CT scanners in Brazil

Background The development of products and services for health care systems is one of the most important phenomena to have occurred in the field of health care over the last 50 years. It generates significant commercial, medical and social results. Although much has been done to understand how health technologies are adopted and regulated in developed countries, little attention has been paid to the situation in low- and middle-income countries (LMICs). Here we examine the institutional environment in which decisions are made regarding the adoption of expensive medical devices into the Brazilian health care system. Methods We used a case study strategy to address our research question. The empirical work relied on in-depth interviews (N = 16) with representatives of a wide range of actors and stakeholders that participate in the process of diffusion of CT (computerized tomography) scanners in Brazil, including manufacturers, health care organizations, medical specialty societies, health insurance companies, regulatory agencies and the Ministry of Health. Results The adoption of CT scanners is not determined by health policy makers or third-party payers of public and private sectors. Instead, decisions are primarily made by administrators of individual hospitals and clinics, strongly influenced by both physicians and sales representatives of the medical industry who act as change agents. Because this process is not properly regulated by public authorities, health care organizations are free to decide whether, when and how they will adopt a particular technology. Conclusions Our study identifies problems in how health care systems in LMICs adopt new, expensive medical technologies, and suggests that a set of innovative approaches and policy instruments are needed in order to balance the institutional and professional desire to practise a modern and expensive medicine in a context of health inequalities and basic health needs.

A hypothesis for explaining single outbreaks (like the Black Death in European cities) of vector-borne infections

We propose a mechanism by which single outbreaks of vector-borne infections can happen even when the value of the basic reproduction number, R(o), of the infection is below one. With this hypothesis we have shown that dynamical models simulations demonstrate that the arrival of a relatively small (with respect to the host population) number of infected vectors can trigger a short-lived epidemic but with a huge number of cases. These episodes are characterized by a sudden outbreak in a previously virgin area that last from weeks to a few months, and then disappear without leaving vestiges. The hypothesis proposed in this paper to explain those single outbreaks of vector-borne infections, even when total basic reproduction number, Ro, is less than one (which explain the fact that those infections fail to establish themselves at endemic levels), is that the vector-to-host component of Ro is greater than one and that a sufficient amount of infected vectors are imported to the vulnerable area, triggering the outbreak. We tested the hypothesis by performing numerical simulations that reproduce the observed outbreaks of chikungunya in Italy in 2007 and the plague in Florence in 1348. The theory proposed provides an explanation for isolated outbreaks of vector-borne infections, ways to calculate the size of those outbreaks from the number of infected vectors arriving in the affected areas. Given the ever-increasing worldwide transportation network, providing a high degree of mobility from endemic to virgin areas, the proposed mechanism may have important implications for public health planning. (C) 2009 Elsevier Ltd. All rights reserved.

Predictive models for diagnosis of pleural effusions secondary to tuberculosis or cancer

Background and objective: Tuberculosis (TB) and cancer are two of the main causes of pleural effusions which frequently share similar clinical features and pleural fluid profiles. This study aimed to identify diagnostic models based on clinical and laboratory variables to differentiate tuberculous from malignant pleural effusions. Methods: A retrospective study of 403 patients (200 with TB; 203 with cancer) was undertaken. Univariate analysis was used to select the clinical variables relevant to the models composition. Variables beta coefficients were used to define a numerical score which presented a practical use. The performances of the most efficient models were tested in a sample of pleural exudates (64 new cases). Results: Two models are proposed for the diagnosis of effusions associated with each disease. For TB: (i) adenosine deaminase (ADA), globulins and the absence of malignant cells in the pleural fluid; and (ii) ADA, globulins and fluid appearance. For cancer: (i) patient age, fluid appearance, macrophage percentage and presence of atypical cells in the pleural fluid; and (ii) as for (i) excluding atypical cells. Application of the models to the 64 pleural effusions showed accuracy higher than 85% for all models. Conclusions: The proposed models were effective in suggesting pleural tuberculosis or cancer.

Targeted Mutagenesis in Pathogenic Leptospira Species: Disruption of the LigB Gene Does Not Affect Virulence in Animal Models of Leptospirosis

The pathogenic mechanisms of Leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. This is mainly due to the lack of tools for genetically manipulating pathogenic Leptospira species. Thus, homologous recombination between introduced DNA and the corresponding chromosomal locus has never been demonstrated for this pathogen. Leptospiral immunoglobulin-like repeat (Lig) proteins were previously identified as putative Leptospira virulence factors. In this study, a ligB mutant was constructed by allelic exchange in L. interrogans; in this mutant a spectinomycin resistance (Spc(r)) gene replaced a portion of the ligB coding sequence. Gene disruption was confirmed by PCR, immunoblot analysis, and immunofluorescence studies. The ligB mutant did not show decrease virulence compared to the wild-type strain in the hamster model of leptospirosis. In addition, inoculation of rats with the ligB mutant induced persistent colonization of the kidneys. Finally, LigB was not required to mediate bacterial adherence to cultured cells. Taken together, our data provide the first evidence of site-directed homologous recombination in pathogenic Leptospira species. Furthermore, our data suggest that LigB does not play a major role in dissemination of the pathogen in the host and in the development of acute disease manifestations or persistent renal colonization.

Association between personality disorder and violent behavior pattern

Personality disorders are associated with criminality and antisocial and borderline personalities as strong predictors of violence. Nevertheless antisocial patients show more instrumental violence, while borderline patients more emotional violence. We surveilled medical records of a personality disorder facility, searching data of aggression and crimes against property among 11 patients with antisocial personality disorder and 19 borderline personality disorder. We found that there are differences regarding engagement in violence and lawbreaking according to the personality disorder: antisocial patients statistically engage more in crimes against property than the borderline patients, and more in this kind of crime than in aggression, whilst borderline patients show a tendency to engage more in episodes of aggression and physical violence than antisocial patients, and less in crimes against property. We conclude that the distinct personality leads to a distinct pattern of crimes and violence: antisocial patients are c old and get more involved in crimes requiring more detailed planning, whilst borderline patients are impulsive and engage in explosive episodes of physical violence. Further studies on the association among personality disorder, behavior pattern and violence type may be useful for both treatment and criminal profiling. (C) 2008 Elsevier Ireland Ltd. All rights reserved.