Modelling the control strategies against dengue in Singapore

Notified cases of dengue infections in Singapore reached historical highs in 2004 (9459 cases) and 2005 (13 817 cases) and the reason for such all increase is still to be established. We apply a mathematical model for dengue infection that takes into account the seasonal variation in incidence, characteristic of dengue fever, and which mimics the 2004-2005 epidemics in Singapore. We simulated a set of possible control strategies and confirmed the intuitive belief that killing adult mosquitoes is the most effective strategy to control an ongoing epidemic. On the other hand, the control of immature forms was very efficient ill preventing the resurgence of dengue epidemics. Since the control of immature forms allows the reduction of adulticide, it seems that the best strategy is to combine both adulticide and larvicide control measures during an outbreak, followed by the maintenance of larvicide methods after the epidemic has subsided. In addition, the model showed that the mixed strategy of adulticide and larvicide methods introduced by the government seems to be very effective in reducing the number of cases in the first weeks after the start of control.

Macrophage and TGF-beta immunohistochemical expression in Jorge Lobo`s disease

Jorge Lobo`s disease, or lacaziosis, is a chronic deep mycosis that clinically manifests as solid, variable-sized nodular parakeloidal lesions. Few studies have characterized the in situ cellular and humoral immune response, especially the involvement of cytokines with immunosuppressive effects such as TGF-beta. The objective this paper was to analyze the expression of TGF-beta in cutaneous lesions in lacaziosis and investigate its importance in the etiopathogy of the disease. The results indicate that the abundance of collagen bands, together with weak immunolabeling for CD68 seen in macrophages, indicates a concomitant effect of TGF-beta inhibiting macrophages and inducing fibrosis, which is responsible for the keloid aspect frequently acquired by these lesions. Finally, the evolution of the infection supports the hypothesis that TGF-beta plays a fundamental role in the etiopathology of Lacazia loboi infection, either by inhibiting the cellular immune response mainly mediated by macrophages or by inducing fibrosis. Further studies are necessary to better characterize the phenotype of the inflammatory infiltrate as well as the participation of other cytokines and growth factors in the tissue response of the host in Jorge Lobo`s disease. (C) 2008 Published by Elsevier Inc.

FOR DEBATE A hypothesis for the 2007 dengue outbreak in Singapore

A previous mathematical model explaining dengue in Singapore predicted a reasonable outbreak of about 6500 cases for 2006 and a very mild outbreak with about 2000 cases for 2007. However, only 3051 cases were reported in 2006 while more than 7800 were reported in the first 44 weeks of 2007. We hypothesized that the combination of haze with other local sources of particulate matter had a significant impact on mosquito life expectancy, significantly increasing their mortality rate. To test the hypothesis a mathematical model based on the reproduction number of dengue fever and aimed at comparing the impact of several possible alternative control strategies was proposed. This model also aimed at contributing to the understanding of the causes of dengue resurgence in Singapore in the last decade. The model`s simulation demonstrated that an increase in mosquito mortality in 2006 and either a reduction in mortality or an increase in the carrying capacity of mosquitoes in 2007 explained the patterned observed in Singapore. Based on the model`s simulation we concluded that the fewer than expected number of dengue cases in Singapore in 2006 was caused by an increase in mosquito mortality due to the disproportionate haze affecting the country that year and that particularly favourable environmental conditions in 2007 propitiated mosquitoes with a lower mortality rate, which explains the greater than expected number of dengue cases in 2007. Whether our hypothesis is plausible or not should be debated further.

Hepatitis Delta virus genotype 8 infection in Northeast Brazil: Inheritance from African slaves?

Hepatitis Delta virus (HDV) is endemic worldwide, but its prevalence varies in different geographical areas. While in the Brazilian Amazon, HDV is known to be endemic and to represent a significant public health problem, few studies have assessed its prevalence in other regions in the country. This study evaluated the seroprevalence of HDV among HBsAg chronic carriers from Maranhao state, a region located in the Northeast of Brazil. Among 133 patients, 5 had anti-HD, of whom 3 had HDV RNA. HDV genotypes were characterized by Bayesian phylogenetic analysis of nucleotide sequences from the HDAg coding region. HDV-3 was identified in one patient who lives in Maranhao, but was born in Amazonas state (Western Amazon basin). Phylogenetic analysis shows that this HDV-3 sequence grouped with other HDV-3 sequences isolated in this state, which suggests that the patient probably contracted HDV infection there. Surprisingly, the other two patients were infected with HDV-8, an African genotype. These patients were born and have always lived in Urbano Santos, a rural county of Maranhao state, moreover they had never been to Africa and denied any contact with people from that continent. This is the first description of the HDV-8 in non-native African populations. This genotype may have been introduced to Brazil through the slaves brought to the country from the West Africa regions during the 16-18th centuries. Our results indicate that the need of clinical and epidemiological studies to investigate the presence of this infection in other areas in Brazil. (C) 2011 Elsevier B.V. All rights reserved.

Adverse Drug Reactions and Drug Interactions as Causes of Hospital Admission in Oncology

Context. Although several studies have evaluated the frequency of adverse drug reactions (ADRs) and drug-drug interactions (DDIs) in general medicine, few studies have looked at the epidemiology of adverse drug events (ADEs) in oncology. Objectives. We sought to investigate how many hospital admissions in oncology are related to a DDI or an ADR. Methods. All cancer patients admitted to an oncology ward during an eight-month period had their charts retrospectively evaluated for reasons of hospitalization, using a 4-point scale (definitely, probably, possibly, or unlikely associated) to classify admissions by their probability of being associated with either a DDI or an ADR. Results. From September 2007 to May 2008, there were 550 hospital admissions and 458 were eligible. Among unplanned admissions (n = 298), 39 (13.0%, 95% confidence interval [CI] 9.4%-17.4%) were considered to be associated with an ADE, 33 (11.0%, 95% CI 7.7%-15.2%) with an ADR, and six (2.0%, 95% CI 0.7%-4.3%) with a DDI. The most common DDIs involved warfarin, captopril, and anti-inflammatory agents, and the most frequent ADR was neutropenic fever post-chemotherapy. Most patients were discharged completely recovered, but two patients died. Conclusion. Approximately one in 10 unplanned hospitalizations of cancer patients is associated with an ADE. Prospective and population-based studies are warranted to evaluate their magnitude in oncology. J Pain Symptom Manage 2011;42:342-353. (C) 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

Acute pancreatitis in juvenile systemic lupus erythematosus: a manifestation of macrophage activation syndrome?

Acute pancreatitis (AP) is a rare and life-threatening manifestation of juvenile systemic lupus erythematosus (JSLE). The objective of this study was to evaluate the prevalence and clinical features of AP in our JSLE population. AP was defined according to the presence of abdominal pain or vomiting associated to an increase of pancreatic enzymes and/or pancreatic radiological abnormalities. Of note, in the last 26 years, 5367 patients were followed up at our Pediatric Rheumatology Unit and 263 (4.9%) of them had JSLE diagnosis (ACR criteria). AP was observed in 4.2% (11/263) of JSLE patients. The median of age of the JSLE patients at AP diagnosis was 12.4 years (8.8-17.9). All of them had lupus disease activity at AP onset. Three patients were receiving corticosteroids before AP diagnosis. Interestingly, 10/11 JSLE patients fulfilled preliminary guidelines for macrophage activation syndrome, three of them with macrophage hemophagocytosis in bone marrow aspirate and hyperferritinemia. The hallmark of this syndrome is excessive activation and proliferation of T lymphocytes and macrophages with massive hypersecretion of proinflammatory cytokines and clinically it is characterized by the occurrence of unexplained fever, cytopenia and hyperferritinemia. AP treatment was mainly based on intravenous methylprednisolone. Four JSLE patients with AP died and two developed diabetes mellitus. In conclusion, AP was a rare and severe manifestation in active pediatric lupus. The association between AP and macrophage activation syndrome suggests that the pancreas could be a target organ of this syndrome and that pancreatic enzyme evaluation should also be carried out in all patients. Lupus (2010) 19, 1654 1658.

Tuberculous meningitis in HIV-infected patients in Brazil: clinical and laboratory characteristics and factors associated with mortality

Background: Tuberculous meningitis (TBM) is a growing problem in HIV-infected patients in developing countries, where there is scarce data about this co-infection. Our objectives were to analyze the main features and outcomes of HIV-infected patients with TBM. Methods: This was a retrospective study of HIV-infected Brazilian patients admitted consecutively for TBM. All patients had Mycobacterium tuberculosis isolated from the cerebrospinal fluid (CSF). Presenting clinical and laboratory features were studied. Multivariate analysis was used to identify variables associated with death during hospitalization and at 9 months after diagnosis. Survival was estimated using the Kaplan-Meier method. Results: We included 108 cases (median age 36 years, 72% male). Only 15% had fever, headache, and meningeal signs simultaneously. Forty-eight percent had extrameningeal tuberculosis. The median CD4+ cell count was 65 cells/mu l. Among 90 cases, 7% had primary resistance to isoniazid and 9% presented multidrug-resistant strains. The overall mortality during hospitalization was 29% and at 9 months was 41%. Tachycardia and prior highly active antiretroviral therapy (HAART) were associated with 9-month mortality. The 9-month survival rate was 22% (95% confidence interval 12-43%). Conclusions: Clinical and laboratory manifestations were unspecific. Disseminated tuberculosis and severe immunosuppression were common. Mortality was high and the 9-month survival rate was low. Tachycardia and prior HAART were associated with death within 9 months of diagnosis. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Use of Inverted Fluoroscope`s C-arm During Endoscopic Treatment of Urinary Tract Obstruction in Pregnancy: A Practicable Solution to Cut Radiation

OBJECTIVES To describe the use of pulsed fluoroscopic guidance, to perform endoscopic procedures in pregnant women, by inverting the fluoroscope`s c-arm using a lead thyroid collar to shield the fetus from the direct X-ray beam. The use of radiation during treatment of pregnant patients with urolithiasis remains a recurring dilemma. METHODS Between May 2006 and December 2008, endoscopic treatment due to ureteral stones was attempted in 8 pregnant women. In all cases, we use an inverted fluoroscope`s c-arm during endoscopic treatment associated with 2 lead neck thyroid collars to shield the uterus, protecting the fetus from direct radiation. Indication for treatment was symptomatic ureteral stones unresponsive to medical treatment in 7 and persistent fever in 1. RESULTS Mean ureteral stone size was 8.1 +/- 4.8 mm, located in the left ureter in 5 (62.5%) cases. Three (37.5%) patients had stone located in the upper ureter, 2 (25%) in the middle ureter, and 3 (37.5) in the distal ureter. In 6 cases, ureteral stones were treated using the semi-rigid ureteroscope, whereas in 1 case a flexible ureteroscope was needed. One woman was treated with insertion of a double-J stent due to associated urinary infection. No women has early delivery related to the endoscopic procedure, and all neonates were perfectly normal. CONCLUSIONS We present a technique for endoscopic procedures in pregnant women inverting the fluoroscope`s c-arm and protecting the fetus from the direct X-ray beam. This practical approach should be specially considered when no portable ultrasound and radiologic assistance in available in the operating room. UROLOGY 75: 1505-1508, 2010. (c) 2010 Published by Elsevier Inc.

Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection in children and adolescents

Background & Aims: This multi-center study aimed to prospectively evaluate the safety and efficacy of a genotype-based Pegylated Interferon alfa-2a/Ribavirin therapy in treatment-naive hepatitis C virus (HCV), positive HCV serology, and quantifiable HCV RNA, infected children. Methods: Eighteen children with genotypes 2 and 3 patients (group A) were assigned to medication for 24 weeks, and 47 children with genotypes 1, 4, 5 and 6 patients (group B) for 48 weeks. Results: Early response at week 12 was observed in 83% of group A patients and in 57% of group B patients (p <0.05). End of treatment response was achieved in 94% of patients in group A and in 57% in group B (p <0.001). Sustained virologic response was maintained in 89% of patients in group A and in 57% of patients in group B (p <0.01). Ten patients stopped prematurely the treatment, 2 for serious adverse event (acute hepatitis and thyrotoxicosis), and 8 because of no virologic response at week 24. Peginterferon alfa-2a and Ribavirin dose was adjusted in 15 patients (23%), 11 for neutropenia (17%), and 3 patients (5%), for anemia, respectively. Treatment-related adverse events included fever and flu-like symptoms (54%), irritability depression change of mood (34%), vomiting (23%), abdominal pain (38%), loss of appetite (21.5%) and dermatitis (29%). No influence on height growth was observed. Conclusions: Pegylated inteferon alfa-2a and Ribavirin treatment allowed to achieve SVR in 57% of pediatric patients with genotypes 1, 4, 5 and 6, and in 94% of genotypes 2 and 3. These results show an improved SVR as compared to reference series in adults with similar regimen. (c) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Multiple Clinical Presentations of Lymphoproliferative Disorders in Pediatric Liver Transplant Recipients: A Single-Center Experience

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication following solid organ transplantation that has been linked to Epstein-Barr virus (EBV) infection. The aim of this article was to describe a single-center experience with the multiplicity of clinical presentations of PTLD. Among 350 liver transplantations performed in 303 children, 13 survivor children displayed a histological diagnosis of PTLD (13/242 survivors; 5.4%). The age at diagnosis ranged from 12 to 258 months (median, 47), and the time from transplantation ranged from 1 to 84 months (median, 13). Ten of these children (76.9%) were EBV-naive prior to transplantation. Fever was present in all cases. The clinical signs at presentation were anemia (92.3%), diarrhea and vomiting (69.2%), recurrent upper airway infections (38.4%), Waldeyer ring lymphoid tissue hypertrophy (23.0%), abdominal mass lesions (30.7%), massive cervical and mediastinal adenopathy (15.3%), or gastrointestinal and respiratory symptoms (30.7%). One child developed fulminant hepatic allograft failure secondary to graft involvement by PTLD. Polymorphic PTLD was diagnosed in 6 patients; 7 had the diagnosis of lymphoma. Treatment consisted of stopping immunosuppression as well as starting intravenous gancyclovir and anti-CD20 monoclonal antibody therapy. The mortality rate was 53.8%. The clinical presentation of PTLD varied from fever of unknown origin to fulminant hepatic failure. The other symptoms that may be linked to the diagnosis of PTLD are pancytopenia, tonsil and adenoid hypertrophy, cervical or mediastinal lymph node enlargement, as well as abdominal masses. Despite numerous advances, the optimal treatment approach for PTLD is not completely known and the mortality rate is still high.

Urogenital tuberculosis in immunocompromised patients

Compare the clinicoradiological presentation of urogenital tuberculosis (UGT) between immunocompromised and nonimmunocompromised patients. Eighty patients diagnosed with UGT were divided into two groups: eight immunocompromised patients (four with acquired immunodeficiency syndrome [AIDS], and four renal transplant patients on immunosuppressive therapy) and 72 nonimmunocompromised patients. The groups were compared as for age, signs and symptoms, diagnostic approach, pattern of urogenital organ involvement, and early specific mortality (within 6 months from diagnosis). AIDS patients were younger (median age 26 years, range 16-38 years), and renal transplant patients were older (median age 51.5 years, range 45-57 years), compared with the nonimmunocompromised subjects (median age 35 years, range 12-75 years). Immunocompromised patients had greater frequency of fever (87.5% versus 43.1%, P = 0.024), lower frequency of storage symptoms (37.5% versus 76.4%, P = 0.033), shorter length of disease (< 6 months: 87.5% versus 2.8%, P < 0.001), and larger frequency of disseminated tuberculosis (62.5% versus 18.1%, P = 0.012). Predominantly parenchymatous renal involvement was more frequent in immunocompromised patients (87.5% versus 6.2%, P < 0.001), who also had lower frequency of stenosis of the collecting system (12.5% versus 93.8%, P < 0.001) and contracted bladder (12.5% versus 65.3%, P = 0.001). UGT has a different clinicoradiological presentation in immunocompromised patients, with predominance of systemic symptoms, disseminated tuberculosis, multiple parenchymatous renal foci, and lower frequency of lesions of the collecting system. In the context of immunosuppression, UGT behaves as a severe bacterial infection, with bacteremia and visceral metastatic foci.

Autoinflammatory diseases: Mimics of Autoimmunity or part of its spectrum? Case presentation

Introduction: Autoinflammatory diseases are very rare diseases presenting within a wide clinical spectrum. Recognition of the main clinical features are challenging due to overlapping or mimicking with autoimmune diseases. Discussion: A case series is reviewed to illustrate typical and atypical features and the difficulties of these diagnoses in the low prevalence areas-a typical unrecognized case of familial Mediterranean fever (FMF) in a youngster, an atypical adult case with overlapping of IMF with Behcet disease, and an early presentation of FMF in infant presenting with inflammatory colitis, as well as the overlapping features within the cryopirin diseases spectrum in an 8-year-old boy who presented with systemic onset arthritis. Conclusion: These cases may represent examples of a very puzzling relationship among disorders of innate and adaptive immune systems and inflammation.

Infectious diseases in paediatric pathology: experience from a developing country

Infectious and parasitic diseases have always challenged man. Although many of them are typically seen in some areas of the world and can be adequately managed by just improving socioeconomic status and sanitary conditions, they are still quite prevalent and may sometimes be seen outside their original geographical areas. Human migration due to different reasons, tourism, blood transfusion and solid organ transplantation has created new concerns for health professionals all over the world. If not for diagnostic purposes, at least these tropical and infectious diseases should be largely known because their epidemiology, pathogenesis, host/parasite interaction, inflammatory and reparative responses are quite interesting and teach us about human biology. Curiosity is inherent to pathology practice and so we are compelled to look for things other than tumours or degenerative diseases. This review focuses on infectious and parasitic diseases found in a developing country and brings up-to-date information on diseases caused by viruses (dengue, yellow fever), bacteria (typhoid fever, leprosy), parasites (Chagas` disease, cutaneous and visceral leishmaniasis, amoebiasis, Capillaria hepatica, schistosomiasis, cysticercosis) and caused by fungi (paracoccidioidomycosis, cryptococcosis, histoplasmosis) that may be useful for pathologists when facing somewhat strange cases from developing countries.

Apoptosis induced by Oropouche virus infection in HeLa cells is dependent on virus protein expression

Oropouche (OROV) is a single-stranded RNA arbovirus of the family Bunyaviridae, genus Orthobunyavirus, which has caused over half a million cases of febrile illness in Brazil in the past 30 years. OROV fever has been registered almost exclusively in the Amazon region, but global warming, deforestation and redistribution of vectors and animal reservoirs increases the risk of Oropouche virus emergence in other areas. OROV causes a cytolytical infection in cultured cells with characteristic cytopathic effect 48 h post-infection. We have studied the mechanisms of apoptosis induced by OROV in HeLa cells and found that OROV causes DNA fragmentation detectable by gel electrophoresis and by flow cytometric analysis of the Sub-G1 population at 36 h post-infection. Mitochondrial release of cytochrome C and activation of caspases 9 and 3 were also detected by western blot analysis. Lack of apoptosis induced by UV-inactivated OROV reveals that virus-receptor binding is not sufficient to induce cell death. Results obtained in cells treated with chloroquine and cycloheximide indicated that viral uncoating and replication are required for apoptosis induction by OROV. Furthermore, treatment of the cells with pan-caspase inhibitor prevented OROV-induced apoptosis without affecting virus progeny production. The results show that OROV infection in vitro causes apoptosis by an intracellular pathway involving mitochondria, and activated by a mechanism dependent on viral replication and protein synthesis. (C) 2010 Elsevier B.V. All rights reserved.

A transposon toolkit for gene transfer and mutagenesis in protozoan parasites

Protozoan parasites affect millions of people around the world. Treatment and control of these diseases are complicated partly due to the intricate biology of these organisms. The interactions of species of Plasmodium, Leishmania and trypanosomes with their hosts are mediated by an unusual control of gene expression that is not fully understood. The availability of the genome sequence of these protozoa sets the stage for using more comprehensive, genome-wide strategies to study gene function. Transposons are effective tools for the systematic introduction of genetic alterations and different transposition systems have been adapted to study gene function in these human pathogens. A mariner transposon toolkit for use in vivo or in vitro in Leishmania parasites has been developed and can be used in a variety of applications. These modified mariner elements not only permit the inactivation of genes, but also mediate the rescue of translational gene fusions, bringing a major contribution to the investigation of Leishmania gene function. The piggyBac and Tn5 transposons have also been shown to mobilize across Plasmodium spp. genomes circumventing the current limitations in the genetic manipulation of these organisms.