Eduardo Martins Netto

Acute Chagas disease outbreak associated with oral transmission

Seven individuals living in a town in the Southwest of Bahia developed sudden signs of cardiac and systemic impairment, with lethality of 28.6%. Serological tests were positive at least in one test in the five patients examined. Forty percent of the Triatoma sordida mynphs found inside or around Trypanosoma cruzi were found by blood culturig in there out five cases the homes of these cases were positive for Trypanosoma cruzi. Transmission probably occurred through consumption of water contaminated with triatomine feces. These findings emphasize the necessity to evaluation the importance of vectors like Triatoma sordida in maintaining the endemicity of this disease.

Use of Protein Antigens for Early Serological Diagnosis of Leprosy

ABSTRACT Leprosy is a chronic and debilitating human disease caused by infection with the Mycobacterium leprae bacillus. Despite the marked reduction in the number of registered worldwide leprosy cases as a result of the widespread use of multidrug therapy, the number of new cases detected each year remains relatively stable. This indicates that M. leprae is still being transmitted and that, without earlier diagnosis, M. leprae infection will continue to pose a health problem. Current diagnostic techniques, based on the appearance of clinical symptoms or of immunoglobulin M (IgM) antibodies that recognize the bacterial phenolic glycolipid I, are unable to reliably identify early-stage leprosy. In this study we examine the ability of IgG within leprosy patient sera to bind several M. leprae protein antigens. As expected, multibacillary leprosy patients provided stronger responses than paucibacillary leprosy patients. We demonstrate that the geographic locations of the patients can influence the antigens they recognize but that ML0405 and ML2331 are recognized by sera from diverse regions (the Philippines, coastal and central Brazil, and Japan). A fusion construct of these two proteins (designated leprosy IDRI diagnostic 1 [LID-1]) retained the diagnostic activity of the component antigens. Upon testing against a panel of prospective sera from individuals who developed leprosy, we determined that LID-1 was capable of diagnosing leprosy 6 to 8 months before the onset of clinical symptoms. A serological diagnostic test capable of identifying and allowing treatment of early-stage leprosy could reduce transmission, prevent functional disabilities and stigmatizing deformities, and facilitate leprosy eradication.

Visceral leishmaniasis in a new ecological niche near a major metropolitan area of Brazil

In 1991, a community cross-sectional study was conducted in a village situated near the beach and close to Salvador, the capital city of Bahia, in Brazil, to determine the prevalence of visceral leishmaniasis since 1989. A serological survey was made of human and canine reservoirs and an intradermal skin test for leishmaniasis was used to assess cellular immune responses. Nearly 30% of the 243 individuals in the study area had positive skin tests and 14% had positive serology, the latter being compatible with recent infection; 29 of 460 dogs examined were seropositive. A possible association was observed between human infection and the presence of dogs in or near residences, but not between human infection and malnutrition. This report describes the evolution of a new focus of visceral leishmaniasis, its expansion toward a metropolitan area, and current measures taken to control the epidemic.

Pre-micro rna signatures delineate stages of endothelial cell transformation in kaposi sarcoma

MicroRNAs (miRNA) have emerged as key regulators of cell lineage differentiation and cancer. We used precursor miRNA profiling by a novel real-time QPCR method (i) to define progressive stages of endothelial cell transformation cumulating in Kaposi sarcoma (KS) and (ii) to identify specific miRNAs that serve as biomarkers for tumor progression. We were able to compare primary patient biopsies to well-established culture and mouse tumor models. Loss of mir-221 and gain of mir-15 expression demarked the transition from merely immortalized to fully tumorigenic endothelial cells. Mir-140 and Kaposi sarcoma–associated herpesvirus viral miRNAs increased linearly with the degree of transformation. Mir-24 emerged as a biomarker specific for KS.

Immunotherapy for Drug-Refractory Mucosal Leishmaniasis

BACKGROUND Pentavalent antimony (Sb(v)) is the mainstay therapy for mucosal leishmaniasis (ML), but it is toxic, and relapses are common. Immunotherapy using a mixture of killed parasites, with or without bacille Calmette-Guerin, is an alternative but is used sporadically because of inconsistent results. METHODS We developed a defined immunotherapeutic antigen preparation for use in an observational, open-label trial to treat 6 patients with ML with a history of Sb(v) therapy failure. All patients were treated with the antigens thiol-specific antioxidant, Leishmania major stress inducible protein 1, Leishmania elongation initiation factor, and Leishmania heat shock protein 83, plus granulocyte-macrophage colony-stimulating factor. Patients underwent clinical and pathological evaluations before the initiation of immunotherapy and at 3, 6, 9, 12, 18, 24, and 60 months after. RESULTS One month after the third injection, 1 patient showed complete clinical remission (CC) and remained disease free for the duration of the study. At the 9-month follow-up examination, 5 patients showed CC, and all patients were asymptomatic at a subsequent 5-year follow-up examination. CONCLUSIONS These data support the concept that vaccine therapy with a defined antigen combination, used with standard chemotherapy, is a safe and effective approach to treat drug-refractory ML.

Efficacy and safety of Efavirenz in HIV patients on Rifampin for tuberculosis

Forty-nine AIDS patients, most of who were antiretroviral therapy (ARV) naive, with active tuberculosis, were treated with Rifampin 600 mg, Isoniazid 400 mg and Pirazinamide 2 g daily. They also received ARV, consisting of Efavirenz (600 mg/day) plus 2 NRTIs. All patients were prospectively followed for at least 24 months. Baselines were: male/female ratio 2:1, mean age 34.7 +/- 9.4 yrs; weight 51 +/- 9.0 kg, viral load 5.6 +/- 0.6 logs, CD4 cell count 101 +/- 128 cells/ mm3. Follow up mean values of data logs of VL and CD4+ cell /mm3 counts were: VL 1.7 and CD4+ 265; VL 1.3 and CD4+ 251; VL 1.4 and CD4+ 326 at 6, 12 and 24 months, respectively. Weight gain changes were: 5 +/- 9.9 +/- 12 and 21 +/- 16 kg respectively at 6, 12 and 24 months. A non-concomitant ARV regimen was introduced at least three weeks after TB treatment initiation. Severe adverse reactions included rash (two), toxic hepatitis (six), Immune Reconstitution Syndrome (seven), and four deaths. We conclude that Efavirenz at a daily dose of 600 mg is sufficient and safe to treat HIV/TB patients using a Rifampin containing regimen.

Primary Antiretroviral Drug Resistance among HIV Type 1-Infected Individuals in Brazil

Infection with drug-resistant human immunodeficiency virus type 1 (HIV-1) has been documented in all countries that have surveyed for it and may result in an unfavorable response to therapy. The prevalence and characteristics of individuals with transmitted resistance to antiretroviral drugs have been scarcely described in Brazil. We performed antiretroviral resistance testing prior to initiation of therapy in 400 subjects enrolled from 20 centers in 13 Brazilian cities between March and September 2007. Genotyping was conducted using PCR-amplified HIV pol products by automated sequencing, and genotype interpretation was done according to the IAS-USA consensus. Of 400 eligible participants, 387 (95.8%) were successfully tested. Seven percent of antiretroviral-naive patients carried viruses with one or more major mutation associated with drug resistance. The prevalence of these mutations was 1.0% for protease inhibitors, 4.4% for nonnucleoside reverse transcriptase inhibitors, and 1.3% for nucleoside reverse transcriptase inhibitors. The frequency of multidrug resistance among the resistant strains was 13.6%. Among subjects infected with drug-resistant virus, the majority were infected with subtype B viruses (91%). Subjects from the city of São Paulo had higher transmitted resistance mutations compared to the rest of the country. Reporting a partner taking antiretroviral medications was associated with a higher chance of harboring HIV variants with major drug resistance mutations [odds ratio = 2.57 (95% confidence interval, 1.07-6.16); p = 0.014]. Resistance testing in drug-naive individuals identified 7% of subjects with mutations associated with reduced susceptibility to antiretroviral drugs. Continued surveillance of drug-resistant HIV-1 in Brazil is warranted when guidelines for HIV prophylaxis and treatment are updated. Resistance testing among drug-naive patients prior to treatment initiation should be considered, mainly directed at subjects whose partners are already on antiretroviral therapy.

Treatment of canine visceral leishmaniasis by the vaccine Leish-111f+MPL-SE

Immunotherapy of canine visceral leishmaniasis (CVL) may provide an alternative to both marginally effective chemotherapy and undesired euthanasia of infected dogs and could have a great impact not only on animal welfare, but also on control of human disease. Therefore, we examined the potential immunotherapeutic efficacy of the subunit vaccine Leish-111f+MPL-SE, which has undergone rigorous preclinical testing and been demonstrated safe in human clinical trials. Two separate trials were performed in Salvador, Brazil, to evaluate the vaccine for therapeutic efficacy against CVL caused by natural infection: an Open Trial and a Blinded Trial. In the Open Trial 59 dogs with clinically active CVL were sequentially allocated to four groups: group 1 received Leish-111f+MPL-SE; group 2 was treated with Glucantime; group 3 received a combination of the vaccine and Glucantime; and group 4 was given no treatment. At the 6-month assessment, the 13 non-treated dogs had either died or showed no clinical improvement. In contrast, most dogs in groups 1-3 showed initial improvement (100%, 80%, and 92%, respectively). Upon evaluation for a mean of 36 months after therapy, the following cure rates were observed: 75% for group 1 dogs (exact 95% confidence interval [CI] 43-95%), 64% for group 2 dogs (exact 95% CI 31-89%), and 50% for group 3 dogs (exact 95% CI 19-81%). Therapeutic efficacy of the Leish-111f+MPL-SE vaccine was reconfirmed in a subsequent Blinded Trial. The vaccine was effective for mild cases of CVL and was compromised in dogs with severe disease. Although further studies are required to understand mechanisms of action, the Leish-111f+MPL-SE vaccine is a promising tool to control VL in both dogs and humans.

Evaluation of blood stream infections by Candida in three tertiary hospitals in Salvador, Brazil: a case-control study

Invasive infections caused by Candida spp. are an important problem in immunocompromised patients. There is scarce data on the epidemiology of blood stream candidiasis in Salvador, Brazil. This study evaluates the risk factors associated with candidemia, among patients admitted to three tertiary, private hospitals, in Salvador, Brazil. We conducted a case-control, retrospective study to compare patients with diagnosis of candidemia in three different tertiary hospitals in Salvador, Brazil. Patients were matched for nosocomial, acquired infections, according to the causal agent: cases were defined by positive blood cultures for Candida species. Controls were those patients who had a diagnosis of systemic bacterial infection, with a positive blood culture to any bacteria, within the same time period (+/- 30 days) of case identification. The groups were compared for the main known risk factors for candidemia and for mortality rates. A hundred thirty-eight patients were identified. Among the 69 cases, only 14 were diagnosed as infected by Candida albicans. Candida species were defined in only eight cultures: C. tropicalis (4 cases), C. glabrata, C. parapsilosis, C. guillermondi, C. formata (1 case each). The main risk factors, identified in a univariate analysis, were: presence of a central venous catheter (CVC), use of parenteral nutrition support (PNS), previous exposure to antibiotics, and chronic renal failure (CRF). No association was detected with surgical procedures, diabetes mellitus, neutropenia or malignancies. Patients were more likely to die during the hospitalization period, but the rates of death caused by the infections were similar for cases and controls. The length of hospitalization was similar for both groups, as well as the time for a positive blood culture. Blood stream infection by Candida spp. is associated with CVC, PNS, previous use of antibiotics, and CRF. The higher mortality rate for cases probably better reflects the severity of the underlying diseases, than as a direct consequence of Candidemia.

Co-infection with HTLV-1 is associated with a shorter survival time for HIV-1-infected patients in Bahia, Brazil

Co-infection with HTLV-1 reaches 20% among patients infected by HIV-1 in Bahia, Brazil. To evaluate its impact on survival, we conducted a retrospective, case-control study involving 198 patients (63 cases). Co-infection was associated with parenteral exposure (P = 0.0001) and female sex (P = 0.02). Co-infected patients had a shorter mean survival (1849 days) than controls (2430 days, P = 0.001), regardless of sex or baseline CD4 cell count. In Bahia, Brazil, co-infection with HIV-1 and HTLV-1 is associated with a shorter survival time.