Diagnosis and clinical significance of Human bocavirus 1 in children hospitalized for lower acute respiratory infection: molecular detection in respiratory secretions and serum.

Introduction. Human bocavirus 1 (HBoV1) infection occurs with viral genome presence in respiratory secretions (RS) and serum, and therefore both samples can be used for diagnosis.Gap statement. The diagnostic sensitivity of HBoV1 DNA detection in serum and the duration of DNAaemia in severe clinical cases have not been elucidated.Aim. To determine HBoV1 DNA in serum and RS of paediatric patients hospitalized for lower acute respiratory infection (LARI) and to analyse the clinical-epidemiological features of positive cases.Methodology. This was a prospective, transverse study. Physicians selected the clinical situations and obtained paired clinical samples (RS and serum) that were tested by PCR/qPCR for HBoV1. Positive cases were analysed considering time of specimen collection, co-detection, clinical manifestations and viral load; statistical significant level was set at α=0.05.Results. HBoV1 was detected in 98 of 402 cases included (24 %); 18/98 (18 %) patients had the virus detectable in serum and 91/98 (93 %) in RS (P<0.001). Positivity rates were not significantly different in patients with RS and serum collected within or beyond 24 h of admission. Single HBoV1 infection was identified in 39/98 patients (40 %), three patients had HBoV1 in both clinical samples (3/39, 8 %) and 32 (32/39, 82 %) only in RS, 22 of them (69 %) with both clinical samples within 24 h of admission. Cough (P=0.001) and rhinitis (P=0.003) were significantly frequent among them and most patients were diagnosed with bronchiolitis (22/39, 56 %) and pneumonia (9/39, 23 %), which was more frequent compared to cases with co-infection (P=0.04). No significant differences were identified among patients with high, medium or low viral load of HBoV1 regarding rate of positivity in both clinical samples, the time of collection of RS and serum, co-detection, first episode of LARI, clinical manifestations, comorbidity or requirement for assisted ventilation. Intensive care unit (ICU) patients had a significantly higher frequency of detection (P<0.001) and co-detection (P=0.001) compared to patients on standard care.Conclusions. HBoV1 is prevalent among infant patients hospitalized for LARI and including it in the standard testing can add to the aetiological diagnosis in these cases, especially for patients admitted to the ICU. HBoV1 detection in serum did not contribute significantly to the diagnosis as compared to detection in respiratory secretions.

Generalized and fatal felid alphaherpesvirus-1 natural infection with liver involvement in a feline leukaemia virus-positive adult cat: a case report.

Generalized and fatal felid alphaherpesvirus-1 (FeHV-1) natural infection with liver involvement is rarely reported in cats, and the occurrence of herpesvirus viraemia with internal organ histologic lesions in adult cats is unknown. A 1.5-year-old cat, female, mixed breed, positive for feline leukaemia virus (FeLV) presented in a veterinary teaching hospital with sneezing, nasal discharge, anorexia, and diarrhoea after two weeks, evolving to inspiratory dyspnoea. Complete blood count and serum biochemistry analysis showed marked leukopenia and thrombocytopenia. After clinical worsening and lack of treatment response, the cat was euthanized. Pathological findings included hepatic necrosis, fibrinonecrotic tracheitis, and bronchointerstitial pneumonia. Marked amounts of coccobacillary bacteria were observed covering the necrotic tracheal and bronchial mucosa, at the cytoplasm of alveolar macrophages, and free in alveoli lumen, mimicking a primary bacterial tracheitis and pneumonia. Both lung and tracheal bacteria exhibited marked immunolabeling in anti-Escherichia coli immunohistochemistry. In addition, rare epithelial cells of bronchi contained round, eosinophilic, intranuclear viral inclusion bodies (4-7 µm) that marginate the chromatin, characteristic of FeHV-1 infection. Strong multifocal anti-FeHV-1 immunolabeling was observed in necrotic epithelial cells of the liver, trachea, and lungs. Generalized herpesvirus infection with the occurrence of acute hepatic necrosis and severe respiratory illness is a potential differential diagnosis in FeLV-positive cats with respiratory signs. The immunodepression in these cats probably favours a FeHV-1 viraemia in addition to the development of opportunistic bacterial infections, such as Escherichia coli, and it is associated with a poor outcome.

First detection of spring viraemia of carp virus in common carp (Cyprinus carpio L.) affected by a septicaemic disease in Mexico.

Spring viraemia of carp (SVC) is an infectious disease responsible for severe economic losses for various cyprinid species, particularly common carp (Cyprinus carpio carpio). The causative agent is the SVC virus (SVCV), a member of the Sprivivirus genus, Rhabdoviridae family, and a List 1 pathogen notifiable by the World Organization for Animal Health. This study describes the diagnosis of an SVCV pathogen isolated in October 2015 from wild common carp inhabiting a natural lagoon in central Mexico. While neither an epidemic nor fish mortalities were reported, the collected killed specimens exhibited clinical signs of disease (e.g., exopthalmia, moderate abdominal distension and haemorrhaging, as well as internal haemorrhages and adhesions). Histological results of injuries were consistent with the pathology caused by SVCV. This finding was supported by the isolation of a virus in EPC and BF-2 cells and subsequent RT-PCR confirmation of SVCV. The phylogenetic analyses of partial SVCV glycoprotein gene sequences classified the isolates into the Ia genogroup. These findings make this the first report of SVCV detection in Mexico, extending the southern geographical range of SVCV within North America. However, since this pathogen was detected in fish inhabiting a natural body of water without tributaries or effluents, it is difficult to estimate the risk of SVCV for other wild/feral cohabitating cyprinid species in the lagoon. The status of this virus is also unknown for other bodies of water within this region.

NS1 Antigenemia and Viraemia Load: Potential Markers of Progression to Dengue Fatal Outcome?

Dengue is a worldwide problem characterized by a multifactorial pathogenesis. Considering the viral components, it is known that high viremia or high levels of the secreted nonstructural protein 1 (NS1) may be associated with a more severe disease. We aimed to characterize the NS1 antigenemia and viremia in dengue fatal and non-fatal cases, as potential markers of progression to a fatal outcome. NS1 antigenemia and viremia were determined in Brazilian dengue fatal cases (n = 40) and non-fatal cases (n = 40), representative of the four dengue virus (DENV) serotypes. Overall, the fatal cases presented higher NS1 levels and viremia. Moreover, the fatal cases from secondary infections showed significantly higher NS1 levels than the non-fatal ones. Here, irrespective of the disease outcome, DENV-1 cases presented higher NS1 levels than the other serotypes. However, DENV-2 and DENV-4 fatal cases had higher NS1 antigenemia than the non-fatal cases with the same serotype. The viremia in the fatal cases was higher than in the non-fatal ones, with DENV-3 and DENV-4 presenting higher viral loads. Viral components, such as NS1 and viral RNA, may be factors influencing the disease outcome. However, the host immune status, comorbidities, and access to adequate medical support cannot be ruled out as interfering in the disease outcome.

Global epidemiology of hepatitis C virus infection: An up-date of the distribution and circulation of hepatitis C virus genotypes.

AIM: To review Hepatitis C virus (HCV) prevalence and genotypes distribution worldwide. METHODS: We conducted a systematic study which represents one of the most comprehensive effort to quantify global HCV epidemiology, using the best available published data between 2000 and 2015 from 138 countries (about 90% of the global population), grouped in 20 geographical areas (with the exclusion of Oceania), as defined by the Global Burden of Diseases project (GBD). Countries for which we were unable to obtain HCV genotype prevalence data were excluded from calculations of regional proportions, although their populations were included in the total population size of each region when generating regional genotype prevalence estimates. RESULTS: Total global HCV prevalence is estimated at 2.5% (177.5 million of HCV infected adults), ranging from 2.9% in Africa and 1.3% in Americas, with a global viraemic rate of 67% (118.9 million of HCV RNA positive cases), varying from 64.4% in Asia to 74.8% in Australasia. HCV genotype 1 is the most prevalent worldwide (49.1%), followed by genotype 3 (17.9%), 4 (16.8%) and 2 (11.0%). Genotypes 5 and 6 are responsible for the remaining < 5%. While genotypes 1 and 3 are common worldwide, the largest proportion of genotypes 4 and 5 is in lower-income countries. Although HCV genotypes 1 and 3 infections are the most prevalent globally (67.0% if considered together), other genotypes are found more commonly in lower-income countries where still account for a significant proportion of HCV cases. CONCLUSION: A more precise knowledge of HCV genotype distribution will be helpful to best inform national healthcare models to improve access to new treatments.

La vacuna polio oral en lactantes no interfiere con la detección de enterovirus en sangre / Oral polio vaccine in infants does not interfere in detection of enterovirus in blood

Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with pre-vaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.

Introducción: No existen estudios que indiquen si la vacuna polio oral (VPO) produce viremia detectable mediante métodos moleculares. Una eventual viremia podría afectar el rendimiento de la RPC tiempo real para detectar enterovirus (EV) no polio, examen de creciente uso clínico en lactantes pequeños con fiebre sin foco. Objetivo: Determinar viremia post VPO en lactantes sanos, por métodos moleculares. Métodos: 50 menores de 3 meses, al momento de recibir su primera VPO se distribuyeron en forma aleatoria en 5 grupos: control, muestra de sangre pre-vacunación; grupo 1, muestra al 2° día; grupo 2, al 4° día; grupo 3, al 6° día y grupo 4, al 8° día post-vacunación. Se realizó RPC convencional específica para virus polio y RPC tiempo real para EV no polio en las muestras de sangre y en muestras de VPO. Resultados: No se identificó presencia de material genético de virus polio en lactante alguno, mientras que en 9 (18%) se identificó presencia de EV no polio. La RPC tiempo real para EV no polio no amplificó material genético a partir de las muestras de VPO. Discusión: Los resultados sugieren que no existe viremia post-VPO detectable por métodos moleculares. Considerando que la RPC tiempo real de EV no polio de uso clínico no permite identificar la presencia de virus polio, estos hallazgos indican que no existirán falsos positivos de este examen como resultado de una vacunación VPO reciente. Adicionalmente se documentó presencia de EV no polio en sangre de lactantes asintomáticos.