Overview of latest articles and publications on ebola in PubMed. PubMed is a service of the US National Library of Medicine that includes over 18 million citations from MEDLINE and other life science journals.
- Control of dengue: Consensus views of Endemic Disease Control Agents and Community Health Agents on their integrated action.
Pessoa JP, Oliveira ES, Teixeira RA, et al. Control of dengue: Consensus views of Endemic Disease Control Agents and Community Health Agents on their integrated action. [JOURNAL ARTICLE]Cien Saude Colet 2016 Aug; 21(8):2329-2338.Dengue is one of Brazil's most important public health challenges. Activities for its prevention and control have been based on the strategy of integrated management proposed in health policies, in which the central actors are the Endemic Disease Control Agent(ACE) and the Community Health Agent (ACS). This study analyzes consensus opinions produced by ACSs and ACEs on theactions for incorporating ACEs into the teams of the Family Health Strategy (ESF). It is a qualitative study from a large municipality in Brazil in which dengue is endemic, using a focus group of professionals that is subsequently analyzed using Collective Subject Discourse Analysis, supported by WebQDA. The results indicate consensus positions in relation to the following subjects: I) difficulty in the process of integration of ACSs and ACEs for control of dengue; II) inclusion of ACEs in the primary healthcare of the ESF; and III) absence of monitoring and assessment of the integrated actions. In conclusion, there are needs: to make participants more aware, seeking changes in behavior; to offer an environment of support to those involved with training courses about dengue; and to monitor the process of integration, and evaluate it periodically, creating indicators of quality and quantity.
- Incidence and Risk Factors for Developing Dengue-Associated Hemophagocytic Lymphohistiocytosis in Puerto Rico, 2008 - 2013.
Ellis EM, Sharp TM, Pérez-Padilla J, et al. Incidence and Risk Factors for Developing Dengue-Associated Hemophagocytic Lymphohistiocytosis in Puerto Rico, 2008 - 2013. [JOURNAL ARTICLE]PLoS Negl Trop Dis 2016 Aug; 10(8):e0004939.Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially fatal disorder characterized by fever, pancytopenia, hepatosplenomegaly, and increased serum ferritin. HLH is being increasingly reported as a complication of dengue, a common tropical acute febrile illness.After a cluster of pediatric dengue-associated HLH patients was identified during the 2012-2013 dengue epidemic in Puerto Rico, active surveillance and a case-control investigation was conducted at four referral hospitals to determine the incidence of HLH in children and identify risk factors for HLH following dengue. Patients with dengue-associated HLH (cases) were matched by month of illness onset and admission hospital to dengue patients that did not develop HLH (controls). During 2008-2013, a total of 33 HLH patients were identified, of which 22 (67%) were associated with dengue and 1 died (dengue-associated HLH case-fatality rate: 4.5%). Two patients with dengue-associated HLH had illness onset in 2009, none had illness onset during the 2010 dengue epidemic, and 20 had illness onset during the 2012-2013 epidemic. Frequency of infection with either dengue virus (DENV)-1 or DENV-4 did not differ between cases and controls. Cases were younger than controls (median age: 1 vs. 13 years, p < 0.01), were hospitalized longer (18 vs. 5 days, p < 0.01), and were admitted more frequently to pediatric intensive care units (100% vs. 16%, p < 0.01). Cases had co-infection (18.2% vs. 4.5%, p = 0.04), recent influenza-like illness (54.5% vs. 25.0%, p = 0.01), and longer duration of fever (7 vs. 5 days; p < 0.01). Cases were more likely to have lymphadenopathy, hepatomegaly, splenomegaly, anemia, and elevated liver transaminases (p ≤ 0.02).During this cluster of dengue-associated HLH cases that was temporally associated with the 2012-2013 epidemic, most patients with dengue-associated HLH were infants and had higher morbidity than dengue inpatients. Physicians throughout the tropics should be aware of HLH as a potential complication of dengue, particularly in patients with anemia and severe liver injury.
- Identification of RNA Binding Proteins Associated with Dengue Virus RNA in Infected Cells Reveals Temporally Distinct Host Factor Requirements.
Viktorovskaya OV, Greco TM, Cristea IM, et al. Identification of RNA Binding Proteins Associated with Dengue Virus RNA in Infected Cells Reveals Temporally Distinct Host Factor Requirements. [JOURNAL ARTICLE]PLoS Negl Trop Dis 2016 Aug; 10(8):e0004921.There are currently no vaccines or antivirals available for dengue virus infection, which can cause dengue hemorrhagic fever and death. A better understanding of the host pathogen interaction is required to develop effective therapies to treat DENV. In particular, very little is known about how cellular RNA binding proteins interact with viral RNAs. RNAs within cells are not naked; rather they are coated with proteins that affect localization, stability, translation and (for viruses) replication.Seventy-nine novel RNA binding proteins for dengue virus (DENV) were identified by cross-linking proteins to dengue viral RNA during a live infection in human cells. These cellular proteins were specific and distinct from those previously identified for poliovirus, suggesting a specialized role for these factors in DENV amplification. Knockdown of these proteins demonstrated their function as viral host factors, with evidence for some factors acting early, while others late in infection. Their requirement by DENV for efficient amplification is likely specific, since protein knockdown did not impair the cell fitness for viral amplification of an unrelated virus. The protein abundances of these host factors were not significantly altered during DENV infection, suggesting their interaction with DENV RNA was due to specific recruitment mechanisms. However, at the global proteome level, DENV altered the abundances of proteins in particular classes, including transporter proteins, which were down regulated, and proteins in the ubiquitin proteasome pathway, which were up regulated.The method for identification of host factors described here is robust and broadly applicable to all RNA viruses, providing an avenue to determine the conserved or distinct mechanisms through which diverse viruses manage the viral RNA within cells. This study significantly increases the number of cellular factors known to interact with DENV and reveals how DENV modulates and usurps cellular proteins for efficient amplification.
- Congenital Chikungunya Virus Infection after an Outbreak in Salvador, Bahia, Brazil.
Lyra PP, Campos GS, Bandeira ID, et al. Congenital Chikungunya Virus Infection after an Outbreak in Salvador, Bahia, Brazil. [Journal Article]AJP Rep 2016 Jul; 6(3):e299-300.There is little information about the congenital chikungunya virus (CHIKV) transmission. We describe two cases of well-documented congenital CHIKV infection in Salvador-Brazil, where CHIKV has been identified since 2014. The outbreak in the city led to the clinical CHIKV diagnoses of both pregnant women 2 days before delivery. Urine and blood samples from the mothers and newborns were collected and tested for reverse transcription-polymerase chain reaction (PCR) analysis for Zika, dengue, and CHIKV. Both neonates and mothers had positive urine and serum PCR results for CHIKV. The newborns had significant perinatal complications and were admitted to the neonatal intensive care unit. The purpose of our case report is to show how severe congenital CHIKV infection can be and the importance to include CHIKV infection in the differential diagnosis of neonatal sepsis when mothers have clinical signs of the disease and live in an affected area.
- Hematuria among dengue patients: A note on observation.
Sriwijitralai W, Wiwanitkit V Hematuria among dengue patients: A note on observation. [Journal Article]Indian J Urol 2016 Jul-Sep; 32(3):251.
- Secondary Structure and Membrane Topology of the Full-Length Dengue Virus NS4B in Micelles.
Li Y, Wong YL, Lee MY, et al. Secondary Structure and Membrane Topology of the Full-Length Dengue Virus NS4B in Micelles. [JOURNAL ARTICLE]Angew Chem Int Ed Engl 2016 Aug 24.Dengue virus nonstructural protein 4B (NS4B) is a membrane protein consisting of 248 residues with a crucial role in virus replication and interference with the host innate immunity. The dengue virus serotype 3 NS4B was reconstituted into lyso-myristoyl phosphatidylglycerol (LMPG) micelles. Backbone resonance assignment of NS4B was obtained using conventional solution NMR experiments. Further studies suggested that NS4B contained eleven helices and six of them form five potential transmembrane regions. This study provides atomic level information for an important drug target to control flavivirus infections.
- State-of-the-art monitoring in treatment of dengue shock syndrome: a case series.
Moulton SL, Mulligan J, Srikiatkhachorn A, et al. State-of-the-art monitoring in treatment of dengue shock syndrome: a case series. [Journal Article]J Med Case Rep 2016; 10(1):233.Early recognition and treatment of circulatory volume loss is essential in the clinical management of dengue viral infection. We hypothesized that a novel computational algorithm, originally developed for noninvasive monitoring of blood loss in combat casualties, could: (1) indicate the central volume status of children with dengue during the early stages of "shock"; and (2) track fluid resuscitation status.Continuous noninvasive photoplethysmographic waveforms were collected over a 5-month period from three children of Thai ethnicity with clinical suspicion of dengue. Waveform data were processed by the algorithm to calculate each child's Compensatory Reserve Index, where 1 represents supine normovolemia and 0 represents the circulatory volume at which hemodynamic decompensation occurs. Values between 1 and 0 indicate the proportion of reserve remaining before hemodynamic decompensation.This case report describes a 7-year-old Thai boy, another 7-year-old Thai boy, and a 9-year-old Thai boy who exhibited signs and symptoms of dengue shock syndrome; all the children had secondary dengue virus infections, documented by serology and reverse transcriptase polymerase chain reaction. The three boys experienced substantial plasma leakage demonstrated by pleural effusion index >25, ascites, and >20 % hemoconcentration. They received fluid administered intravenously; one received a blood transfusion. All three boys showed a significantly low initial Compensatory Reserve Index (≥0.20), indicating a clinical diagnosis of "near shock". Following 5 days with fluid resuscitation treatment, their Compensatory Reserve Index increased towards "normovolemia" (that is, Compensatory Reserve Index >0.75).The results from these cases demonstrate a new variation in the diagnostic capability to manage patients with dengue shock syndrome. The findings shed new light on a method that can avoid possible adverse effects of shock by noninvasive measurement of a patient's compensatory reserve rather than standard vital signs or invasive diagnostic methods.
- Human heme oxygenase 1 is a potential host cell factor against dengue virus replication.
Tseng CK, Lin CK, Wu YH, et al. Human heme oxygenase 1 is a potential host cell factor against dengue virus replication. [Journal Article]Sci Rep 2016.:32176.Dengue virus (DENV) infection and replication induces oxidative stress, which further contributes to the progression and pathogenesis of the DENV infection. Modulation of host antioxidant molecules may be a useful strategy for interfering with DENV replication. In this study, we showed that induction or exogenous overexpression of heme oxygenase-1 (HO-1), an antioxidant enzyme, effectively inhibited DENV replication in DENV-infected Huh-7 cells. This antiviral effect of HO-1 was attenuated by its inhibitor tin protoporphyrin (SnPP), suggesting that HO-1 was an important cellular factor against DENV replication. Biliverdin but not carbon monoxide and ferrous ions, which are products of the HO-1 on heme, mediated the HO-1-induced anti-DENV effect by non-competitively inhibiting DENV protease, with an inhibition constant (Ki) of 8.55 ± 0.38 μM. Moreover, HO-1 induction or its exogenous overexpression, rescued DENV-suppressed antiviral interferon response. Moreover, we showed that HO-1 induction by cobalt protoporphyrin (CoPP) and andrographolide, a natural product, as evidenced by a significant delay in the onset of disease and mortality, and virus load in the infected mice's brains. These findings clearly revealed that a drug or therapy that induced the HO-1 signal pathway was a promising strategy for treating DENV infection.
- Differential cell line susceptibility to the emerging Zika virus: implications for disease pathogenesis, non-vector-borne human transmission and animal reservoirs.
Chan JF, Yip CC, Tsang JO, et al. Differential cell line susceptibility to the emerging Zika virus: implications for disease pathogenesis, non-vector-borne human transmission and animal reservoirs. [Journal Article]Emerg Microbes Infect 2016.:e93.Zika virus (ZIKV) is unique among human-pathogenic flaviviruses by its association with congenital anomalies and trans-placental and sexual human-to-human transmission. Although the pathogenesis of ZIKV-associated neurological complications has been reported in recent studies, key questions on the pathogenesis of the other clinical manifestations, non-vector-borne transmission and potential animal reservoirs of ZIKV remain unanswered. We systematically characterized the differential cell line susceptibility of 18 human and 15 nonhuman cell lines to two ZIKV isolates (human and primate) and dengue virus type 2 (DENV-2). Productive ZIKV replication (⩾2 log increase in viral load, ZIKV nonstructural protein-1 (NS1) protein expression and cytopathic effects (CPE)) was found in the placental (JEG-3), neuronal (SF268), muscle (RD), retinal (ARPE19), pulmonary (Hep-2 and HFL), colonic (Caco-2),and hepatic (Huh-7) cell lines. These findings helped to explain the trans-placental transmission and other clinical manifestations of ZIKV. Notably, the prostatic (LNCaP), testicular (833KE) and renal (HEK) cell lines showed increased ZIKV load and/or NS1 protein expression without inducing CPE, suggesting their potential roles in sexual transmission with persistent viral replication at these anatomical sites. Comparatively, none of the placental and genital tract cell lines allowed efficient DENV-2 replication. Among the nonhuman cell lines, nonhuman primate (Vero and LLC-MK2), pig (PK-15), rabbit (RK-13), hamster (BHK21) and chicken (DF-1) cell lines supported productive ZIKV replication. These animal species may be important reservoirs and/or potential animal models for ZIKV. The findings in our study help to explain the viral shedding pattern, transmission and pathogenesis of the rapidly disseminating ZIKV, and are useful for optimizing laboratory diagnostics and studies on the pathogenesis and counter-measures of ZIKV.
- Proposal of a Clinical Decision Tree Algorithm Using Factors Associated with Severe Dengue Infection.
Tamibmaniam J, Hussin N, Cheah WK, et al. Proposal of a Clinical Decision Tree Algorithm Using Factors Associated with Severe Dengue Infection. [Journal Article]PLoS One 2016; 11(8):e0161696.AbstractPublisher Full TextWHO's new classification in 2009: dengue with or without warning signs and severe dengue, has necessitated large numbers of admissions to hospitals of dengue patients which in turn has been imposing a huge economical and physical burden on many hospitals around the globe, particularly South East Asia and Malaysia where the disease has seen a rapid surge in numbers in recent years. Lack of a simple tool to differentiate mild from life threatening infection has led to unnecessary hospitalization of dengue patients.We conducted a single-centre, retrospective study involving serologically confirmed dengue fever patients, admitted in a single ward, in Hospital Kuala Lumpur, Malaysia. Data was collected for 4 months from February to May 2014. Socio demography, co-morbidity, days of illness before admission, symptoms, warning signs, vital signs and laboratory result were all recorded. Descriptive statistics was tabulated and simple and multiple logistic regression analysis was done to determine significant risk factors associated with severe dengue.657 patients with confirmed dengue were analysed, of which 59 (9.0%) had severe dengue. Overall, the commonest warning sign were vomiting (36.1%) and abdominal pain (32.1%). Previous co-morbid, vomiting, diarrhoea, pleural effusion, low systolic blood pressure, high haematocrit, low albumin and high urea were found as significant risk factors for severe dengue using simple logistic regression. However the significant risk factors for severe dengue with multiple logistic regressions were only vomiting, pleural effusion, and low systolic blood pressure. Using those 3 risk factors, we plotted an algorithm for predicting severe dengue. When compared to the classification of severe dengue based on the WHO criteria, the decision tree algorithm had a sensitivity of 0.81, specificity of 0.54, positive predictive value of 0.16 and negative predictive of 0.96.The decision tree algorithm proposed in this study showed high sensitivity and NPV in predicting patients with severe dengue that may warrant admission. This tool upon further validation study can be used to help clinicians decide on further managing a patient upon first encounter. It also will have a substantial impact on health resources as low risk patients can be managed as outpatients hence reserving the scarce hospital beds and medical resources for other patients in need.