Human parainfluenza virus 3 vaccine candidates attenuated by codon-pair deoptimization are immunogenic and protective in hamsters.

Human parainfluenza virus type 3 (HPIV3) is a major pediatric respiratory pathogen lacking available vaccines or antiviral drugs. We generated live-attenuated HPIV3 vaccine candidates by codon-pair deoptimization (CPD). HPIV3 open reading frames (ORFs) encoding the nucleoprotein (N), phosphoprotein (P), matrix (M), fusion (F), hemagglutinin-neuraminidase (HN), and polymerase (L) were modified singly or in combination to generate 12 viruses designated Min-N, Min-P, Min-M, Min-FHN, Min-L, Min-NP, Min-NPM, Min-NPL, Min-PM, Min-PFHN, Min-MFHN, and Min-PMFHN. CPD of N or L severely reduced growth in vitro and was not further evaluated. CPD of P or M was associated with increased and decreased interferon (IFN) response in vitro, respectively, but had little effect on virus replication. In Vero cells, CPD of F and HN delayed virus replication, but final titers were comparable to wild-type (wt) HPIV3. In human lung epithelial A549 cells, CPD F and HN induced a stronger IFN response, viral titers were reduced 100-fold, and the expression of F and HN proteins was significantly reduced without affecting N or P or the relative packaging of proteins into virions. Following intranasal infection in hamsters, replication in the nasal turbinates and lungs tended to be the most reduced for viruses bearing CPD F and HN, with maximum reductions of approximately 10-fold. Despite decreased in vivo replication (and lower expression of CPD F and HN in vitro), all viruses induced titers of serum HPIV3-neutralizing antibodies similar to wt and provided complete protection against HPIV3 challenge. In summary, CPD of HPIV3 yielded promising vaccine candidates suitable for further development.

Non-transcriptional IRF7 interacts with NF-κB to inhibit viral inflammation.

Interferon (IFN) regulatory factors (IRF) are key transcription factors in cellular antiviral responses. IRF7, a virus-inducible IRF, expressed primarily in myeloid cells, is required for transcriptional induction of interferon α and antiviral genes. IRF7 is activated by virus-induced phosphorylation in the cytoplasm, leading to its translocation to the nucleus for transcriptional activity. Here, we revealed a nontranscriptional activity of IRF7 contributing to its antiviral functions. IRF7 interacted with the pro-inflammatory transcription factor NF-κB-p65 and inhibited the induction of inflammatory target genes. Using knockdown, knockout, and overexpression strategies, we demonstrated that IRF7 inhibited NF-κB-dependent inflammatory target genes, induced by virus infection or toll-like receptor stimulation. A mutant IRF7, defective in transcriptional activity, interacted with NF-κB-p65 and suppressed NF-κB-induced gene expression. A single-action IRF7 mutant, active in anti-inflammatory function, but defective in transcriptional activity, efficiently suppressed Sendai virus and murine hepatitis virus replication. We, therefore, uncovered an anti-inflammatory function for IRF7, independent of transcriptional activity, contributing to the antiviral response of IRF7.

Evaluation of the immunogenicity and protective efficacy of an inactivated vaccine candidate for sheep infected with ovine parainfluenza virus type 3.

Respiratory diseases constitute a major health problem for ruminants, resulting in considerable economic losses throughout the world. Parainfluenza type 3 virus (PIV3) is one of the most important respiratory pathogens of ruminants. The pathogenicity and phylogenetic analyses of PIV3 virus have been reported in sheep and goats. However, there are no recent studies of the vaccination of sheep or goats against PIV3. Here, we developed a purified inactivated ovine parainfluenza virus type 3 (OPIV3) vaccine candidate. In addition, we immunized sheep with the inactivated OPIV3 vaccine and evaluated the immune response and pathological outcomes associated with OPIV3 TX01 infection. The vaccinated sheep demonstrated no obvious symptoms of respiratory tract infection, and there were no gross lesions or pathological changes in the lungs. The average body weight gain significantly differed between the vaccinated group and the control group (P < 0.01). The serum neutralization antibody levels rapidly increased in sheep post-vaccination and post-challenge with OPIV3. Furthermore, viral shedding in nasal swabs and viral loads in the lungs were reduced. The results of this study suggest that vaccination with this candidate vaccine induces the production of neutralizing antibodies and provides significant protection against OPIV3 infection. These results may be helpful for further studies on prevention and control strategies for OPIV3 infections.

Comparative efficacy of modified-live and inactivated vaccines in boosting responses to bovine respiratory syncytial virus, bovine parainfluenza virus Type 3, and bovine coronavirus following neonatal mucosal priming of beef calves.

Objective: This study compared clinical and immunological responses to coinfection challenge of beef calves mucosally primed and differentially boosted with commercial combination vaccines containing antigens against bovine coronavirus (BCoV), bovine parainfluenza virus Type 3 (BPIV3), and bovine respiratory syncytial virus (BRSV). Animals: Nineteen commercial beef heifers. Procedure: At birth, calves were mucosally (IN) primed with modified-live virus (MLV) vaccines, differentially boosted by injection of either combination MLV (IN-MLV) or inactivated virus (IN-KV) vaccines at a mean age of 44 d, and then challenged by coinfection with BCoV, BPIV3, and BRSV at weaning. Results: Both groups were similarly protected from clinical disease and had anamnestic neutralizing antibody responses to all 3 viruses. The IN-KV group shed more BCoV, and less BPIV3 and BRSV, than the IN-MLV group. Conclusion: These data indicated similar clinical and immunological protection between IN-MLV and IN-KV; however, shed of virus varied. Clinical relevance: Whereas boosting with KV or MLV appeared to have similar efficacy, viral shed differences may affect disease control.

Efficacité comparative des vaccins vivants modifiés et inactivés pour stimuler les réponses au virus respiratoire syncytial bovin, au virus parainfluenza bovin de type 3 et au coronavirus bovin après amorçage via la muqueuse de veaux de boucherie nouveau-nés. Objectif: Cette étude a comparé les réponses cliniques et immunologiques à une co-infection de veaux de boucherie amorcés par voie muqueuse et différentiellement stimulés avec des vaccins combinés commerciaux contenant des antigènes contre le coronavirus bovin (BCoV), le virus parainfluenza bovin de type 3 (BPIV3) et le virus respiratoire syncytial bovin (BRSV). Animaux: Dix-neuf génisses de boucherie commerciales. Procédure: À la naissance, les veaux ont été vaccinés au niveau des muqueuses (IN) avec des vaccins à virus vivants modifiés (MLV), stimulés de manière différentielle par l'injection de vaccins combinés MLV (IN-MLV) ou de virus inactivés (IN-KV) à un âge moyen de 44 jours. puis provoqué par une co-infection avec BCoV, BPIV3 et BRSV au sevrage. Résultats: Les deux groupes étaient protégés de la même manière contre la maladie clinique et présentaient des réponses anamnestiques en anticorps neutralisants contre les 3 virus. Le groupe IN-KV a excrété plus de BCoV et moins de BPIV3 et de BRSV que le groupe IN-MLV. Conclusion: Ces données indiquent une protection clinique et immunologique similaire entre IN-MLV et IN-KV; cependant, l'excrétion du virus variait. Pertinence clinique: Alors que le rappel avec KV ou MLV semble avoir une efficacité similaire, les différences d'excrétion virale peuvent affecter la limitation de la maladie.(Traduit par Dr Serge Messier).

Molecular epidemiology of a Parainfluenza Type 3 virus outbreak: Informing infection control measures on adult hematology wards.

OBJECTIVES: Parainfluenza virus type 3 (PIV3) outbreaks among hematology patients are associated with high morbidity and mortality. Prompt implementation of infection prevention (IP) measures has proven to be the most efficacious approach for controlling PIV3 outbreaks within this patient population. The most suitable IP measures can vary depending on the mode of virus transmission, which remains unidentified in most outbreaks. We describe the molecular epidemiology of an outbreak of PIV3 among hematology patients and the development of a new method that allows for the differentiation of outbreak and community strains, from which a closed outbreak could be inferred. METHODS: Patients were screened for respiratory viruses using multiplex-PCR. PIV3 positive samples with a cycle threshold (Ct)-value of <31 underwent a retrospective characterization via an in-house developed sequence analysis of the hemagglutinin-neuraminidase (HN) gene. RESULTS: Between July and September 2022, 31 hematology patients were identified with PIV3. Although infection control measures were implemented, the outbreak persisted for nine weeks. Sequencing the HN gene of 27 PIV3 strains from 27 patients revealed that all outbreak strains formed a distinct cluster separate from the control strains, suggestive of a nosocomial transmission route. CONCLUSIONS: Sequencing the HN gene of PIV3 strains in an outbreak setting enables outbreak strains to be distinguished from community strains. Early molecular characterization of PIV3 strains during an outbreak can serve as a tool in determining potential transmission routes. This, in turn, enables rapid implementation of targeted infection prevention measures, with the goal of minimizing the outbreak's duration and reducing associated morbidity and mortality.

Genetic Comparison of Human Parainfluenza Virus Type 3 Detected in Respiratory Samples from Patients with Encephalopathy and Airway Inflammation in Aichi Prefecture, Japan.

Human parainfluenza virus type 3 (HPIV-3, human respirovirus 3) is the second most frequently detected virus in lower respiratory tract infections in children after human respiratory syncytial virus (HRSV). HPIV-3, similar to related respiratory viruses such as HRSV and influenza virus, may cause encephalopathy; however, the relevance of HPIV-3 as a pathogenic factor in encephalopathy is unknown. We attempted to detect HPIV-1, HPIV-2, HPIV-3, HPIV-4, HRSV, and human metapneumovirus (HMPV) in 136 patients with encephalitis/encephalopathy or suspected encephalitis/encephalopathy during a 6-year period from 2014 to 2019. HPIV-3 was detected in 6 patients, followed by HRSV in 3 patients. The HPIV-3 strains detected were closely related to those detected in a patient with respiratory disease during the same period. Although HPIV-3 is less widely recognized than HRSV as a triggering virus of encephalopathy, our results suggest that HPIV-3 is as important as HRSV. Surveillance of the causative viruses of encephalopathy, including HPIV-3, would help clarify the causes of encephalopathy in Japan, as the cause is currently reported in less than half of cases in Japan.

Molecular Epidemiology of Human Parainfluenza Virus Type 3 in Children With Acute Respiratory Tract Infection in Hangzhou.

BACKGROUND: Since the outbreak of COVID-19, China has undertaken a variety of preventative and control measures, effectively reducing the incidence of numerous infectious diseases among the pediatric population in Hangzhou. We aim to investigate the genetic and epidemiological characteristics of Human parainfluenza virus-3 (HPIV-3) in pediatric patients during this period. METHODS: A total of 1442 pharyngeal swab samples were collected from outpatients and inpatients with a diagnosis of acute respiratory tract infections (ARTIs) from November 2020 to March 2021. HPIV-3 was detected by quantitative real time polymerase chain reaction (qRT-PCR). The L gene of HPIV-3 positive samples was amplified and sequenced. RESULTS: Among 1442 children with ARTI, the positive rate of HPIV-3 was 7.07% (102/1442). The positive detection rate was the highest in the 6-month to 1-year age group. Coinfection was observed in 36 HPIV-3-positive samples (35.29%, 36/102), and adenovirus (ADV) was the most common coinfecting virus (63.89%, 23/36). The L gene of 48 HPIV-3 positive samples was sequenced. The nucleotide sequence analysis showed high consistency (92.10%-99.40%), and all strains belonged to C3a. CONCLUSIONS: During study periods, the positive detection rate of HPIV-3 among children is high, and the highest proportion of coinfection was observed in HPIV-3 mixed ADV infection. Phylogenetic analysis revealed that the nucleotide sequence of the L gene of HPIV-3 was highly consistent, and the main epidemic strain in this area was the C3a subtype.

Functional and structural basis of human parainfluenza virus type 3 neutralization with human monoclonal antibodies.

Human parainfluenza virus type 3 (hPIV3) is a respiratory pathogen that can cause severe disease in older people and infants. Currently, vaccines against hPIV3 are in clinical trials but none have been approved yet. The haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins of hPIV3 are major antigenic determinants. Here we describe naturally occurring potently neutralizing human antibodies directed against both surface glycoproteins of hPIV3. We isolated seven neutralizing HN-reactive antibodies and a pre-fusion conformation F-reactive antibody from human memory B cells. One HN-binding monoclonal antibody (mAb), designated PIV3-23, exhibited functional attributes including haemagglutination and neuraminidase inhibition. We also delineated the structural basis of neutralization for two HN and one F mAbs. MAbs that neutralized hPIV3 in vitro protected against infection and disease in vivo in a cotton rat model of hPIV3 infection, suggesting correlates of protection for hPIV3 and the potential clinical utility of these mAbs.

Phylogenetic lineage dynamics of global parainfluenza virus type 3 post-COVID-19 pandemic.

During the coronavirus disease 2019 (COVID-19) pandemic, outbreaks of parainfluenza virus type 3 (PIV-3) decreased due to infection control measures. However, a post-pandemic resurgence of PIV-3 has recently been observed. Nonetheless, the role of viral genetic epidemiology, possibly influenced by a genetic bottleneck effect, remains unexplored. We investigated the phylogenetic structure of the publicly available PIV-3 whole-genome and hemagglutinin-neuraminidase (HN) gene sequences spanning the last 65 years, including the COVID-19 pandemic. Sequences were retrieved from the nucleotide database of the National Center for Biotechnology Information using the search term "Human respirovirus 3." Sequence subsets covering all six genes of PIV-3 or the HN gene were designated as the whole-genome and HN surveillance data sets, respectively. Using these data sets, we constructed maximum-likelihood phylogenetic trees and performed a time-scaled analysis using a Bayesian SkyGrid coalescent prior. A total of 455 whole-genome and 1,139 HN gene sequences were extracted, revealing 10 and 11 distinct lineages, respectively, with >98% concurrence in lineage assignments. During the 2020 COVID-19 pandemic, only three single-lineage clusters were identified in Japan, Korea, and the USA. The inferred year of origin for PIV-3 was 1938 (1903-1963) for the whole-genome data set and 1955 (1930-1963) for the HN gene data set. Our study suggests that PIV-3 epidemics in the post-COVID era are likely influenced by a pandemic-driven bottleneck phenomenon and supports previous hypotheses suggesting s that PIV-3 originated during the early half of the 20th century.IMPORTANCEUsing publicly available parainfluenza virus type 3 (PIV-3) whole-genome sequences, we estimated that PIV-3 originated during the 1930s, consistent with previous hypotheses. Lineage typing and time-scaled phylogenetic analysis revealed that PIV-3 experienced a bottleneck phenomenon in Korea and the USA during the coronavirus disease 2019 pandemic. We identified the conservative hemagglutinin-neuraminidase gene as a viable alternative marker in long-term epidemiological studies of PIV-3 when whole-genome analysis is limited.

Critical role of G3BP1 in bovine parainfluenza virus type 3 (BPIV3)-inhibition of stress granules formation and viral replication.

Background: It remains unclear whether BPIV3 infection leads to stress granules formation and whether G3BP1 plays a role in this process and in viral replication. This study aims to clarify the association between BPIV3 and stress granules, explore the effect of G3BP1 on BPIV3 replication, and provide significant insights into the mechanisms by which BPIV3 evades the host's antiviral immunity to support its own survival. Methods: Here, we use Immunofluorescence staining to observe the effect of BPIV3 infection on the assembly of stress granules. Meanwhile, the expression changes of eIF2α and G3BP1 were determined. Overexpression or siRNA silencing of intracellular G3BP1 levels was examined for its regulatory control of BPIV3 replication. Results: We identify that the BPIV3 infection elicited phosphorylation of the eIF2α protein. However, it did not induce the assembly of stress granules; rather, it inhibited the formation of stress granules and downregulated the expression of G3BP1. G3BP1 overexpression facilitated the formation of stress granules within cells and hindered viral replication, while G3BP1 knockdown enhanced BPIV3 expression. Conclusion: This study suggest that G3BP1 plays a crucial role in BPIV3 suppressing stress granule formation and viral replication.

microRNA-guided immunity against respiratory virus infection in human and mouse lung cells.

Viral infectivity depends on multiple factors. Recent studies showed that the interaction between viral RNAs and endogenous microRNAs (miRNAs) regulates viral infectivity; viral RNAs function as a sponge of endogenous miRNAs and result in upregulation of its original target genes, while endogenous miRNAs target viral RNAs directly and result in repression of viral gene expression. In this study, we analyzed the possible interaction between parainfluenza virus RNA and endogenous miRNAs in human and mouse lungs. We showed that the parainfluenza virus can form base pairs with human miRNAs abundantly than mouse miRNAs. Furthermore, we analyzed that the sponge effect of endogenous miRNAs on viral RNAs may induce the upregulation of transcription regulatory factors. Then, we performed RNA-sequence analysis and observed the upregulation of transcription regulatory factors in the early stages of parainfluenza virus infection. Our studies showed how the differential expression of endogenous miRNAs in lungs could contribute to respiratory virus infection and species- or tissue-specific mechanisms and common mechanisms could be conserved in humans and mice and regulated by miRNAs during viral infection.

Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3 / Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

La encefalomielitis aguda diseminada es una enfermedad infrecuente pero de elevada morbi-mortalidad en pacientes adultos. Demanda una sospecha y diagnóstico precoz que requiere el concurso de información clínica, pruebas de laboratorio y estudio de imágenes. De sustrato inmunológico, se puede relacionar a una infección viral, bacteriana o inmunización reciente. Los glucocorticoides son el tratamiento de elección, mientras que la inmunoglobulina intravenosa y la plasmaféresis se reservan para casos refractarios. Se presenta el caso de una encefalomielitis aguda diseminada grave, en un paciente de sexo masculino de 25 años, asociado a una infección respiratoria por virus parainfluenza 3. Requirió conexión a ventilación mecánica y tuvo una respuesta completa con plasmaféresis.

Parainfluenza virus as a cause of acute respiratory infection in hospitalized childrens

Background: Human parainfluenza viruses account for a significant proportion of lower respiratory tract infections in children.Objective: To assess the prevalence of Human parainfluenza viruses as a cause of acute respiratory infection and to compare clinical data for this infection against those of the human respiratory syncytial virus.Methods: A prospective study in children younger than five years with acute respiratory infection was conducted. Detection of respiratory viruses in nasopharyngeal aspirate samples was performed using the indirect immunofluorescence reaction. Length of hospital stay, age, clinical history and physical exam, clinical diagnoses, and evolution (admission to Intensive Care Unit or general ward, discharge or death) were assessed. Past personal (premature birth and cardiopathy) as well as family (smoking and atopy) medical factors were also assessed.Results: A total of 585 patients were included with a median age of 7.9 months and median hospital stay of six days. No difference between the HRSV+ and HPIV+ groups was found in terms of age, gender or length of hospital stay. The HRSV+ group had more fever and cough. Need for admission to the Intensive Care Unit was similar for both groups but more deaths were recorded in the HPIV+ group. The occurrence of parainfluenza peaked during the autumn in the first two years of the study.Conclusion: Parainfluenza was responsible for significant morbidity, proving to be the second-most prevalent viral agent in this population after respiratory syncytial virus. No difference in clinical presentation was found between the two groups, but mortality was higher in the HPIV+ group.

Phylogenetic characterization of bovine parainfluenza 3 from contaminated cell cultures and field isolates from Brazil

Genomic fragments of the HN and L genes from Brazilian bovine parainfluenza 3 virus (bPIV-3) isolated as contaminants from cell cultures and clinical specimens were amplified by reverse transcription-polymerase chain reaction (RT-PCR), sequenced using specific degenerate primers and analyzed by phylogenetic comparison with reference strains of bPI3V. The Brazilian isolates revealed a high degree of genomic when compared to SF4/32 prototype strain, within the recently proposed genotype A of bPIV-3.

Paraparesia espástica tropical/mielopatia associada ao HTLV-1: relato de dois casos com manifestações dermatológicas em familiares de doador de sangue HTLV-1 positivo assintomático no Hemocentro do Amazonas - Hemoam / Tropical spastic paraparesis/myelopathy associated with HTLV-1: report of two related cases with dermatological involvement

Dois casos de paraparesia espástica tropical / mielopatia associada ao HTLV-1 (HAM/TSP) foram diagnosticados no Hemocentro do Amazonas - Hemoam, em familiares de doador de sangue soropositivo para o HTLV-1 assintomático. Aqui descrevemos a investigação familiar, as características clínicas dos casos e as manifestações dermatológicas associadas.

Herein we report on two cases of tropical spastic paraparesis / myelopathy associated with HTLV-1 (HAM/TSP) diagnosed in relatives of a blood donor found positive for HTLV-1 at serologic screening. The donor himself was asymptomatic. Family studies, the clinical characteristics of the cases and the associated dermatologic manifestations are reported.

Características clínicas y epidemiológicas de la infección por virus parainfluenza en niños hospitalizados / Clinical and epidemiological manifestations of parainfluenza infection in hospitalized children

Los virus parainfluenza del ser humano (VPIh) son patógenos importantes de enfermedad respiratoria en niños; pese a ello, existe escasa información publicada en Sudamérica dirigida a caracterizar esta infección. Objetivo: Describir las manifestaciones clínicas y epidemiológicas específicas de los VPIh en niños hospitalizados. Pacientes y Métodos: Se revisaron todas las hospitalizaciones respiratorias (HR) efectuadas en el Hospital de la Pontificia Universidad Católica, Santiago, Chile, durante el período 2001-2004 y sus respectivos estudios virales obtenidos de secreciones nasofaríngeas en aquellos con sospecha de infección viral. Resultados: Se identificaron 3.043 HR siendo 64 (2,1 por ciento) VPUrh La edad promedio fue 13 meses (rango: 1 m-12 a) siendo 77 por ciento) de edad inferior a dos años. VPIh-2 fue el serotipo prevalente (47 por ciento), observándose una tendencia estacional para los serotipos 2 y 3. Las presentaciones más frecuentes fueron sibilancias asociadas a virus (40 por cientoo) y neumonía (30 por ciento). Todas las bronquiolitis se presentaron asociadas a VPIh serotipos 2 y 3. Sólo 17 por ciento de los hospitalizados por VPIh+ (44 por ciento VPIh-1) desarrollaron laringitis. Conclusión: Virus parainfluenza humano puede ser responsable de HR en niños, mostrando una tendencia estacional VPIh-2 y el serotipo 3. Aunque son poco frecuentes como causa de HR, confirmamos su participación como etiología específica de laringitis, bronquiolitis y neumonía, especialmente en niños pequeños.

Background: Human parainfluenza viruses (hPIV) are a common cause of respiratory illness of children but published data on clinical characteristics of hPIV infection in South America is scarce. Objective: To review the clinical presentation and epidemiological features of hPIV in a series of hospitalized children in Chile. Patients and Methods: Retrospective review of clinical charts from all pediatric admissions with a diagnosis of respiratory disease (between January 2001 to December 2004) at the Catholic University Hospital, Santiago, Chile. Nasopharyngeal secretions were tested for hPIV in children admitted with suspected respiratory viral infections. Results: A total of 3,043 respiratory admissions were recorded during the study period; 64 children (2.1 percent) were hPIV positive. Average age was 13 months (range: lm to 12y) and 77 percent> were younger than 2 years. HPIV-2 was the most common type identified (47 percent). A seasonal trend was noted for serotypes hPIV-2 and 3. Acute wheezing (40 percento) and pneumonia (30 percent) were the most common clinical diagnosis in hPIV positive children and 17 percent> hPIV positive children (44 percent> for hPIV-1) were associated with laryngitis. All hPIV positive bronchiolitis were due to serotypes hPIV-2 and 3. Conclusion: hPIV can cause respiratory disease requiring hospitalization; serotypes hPIV-2 and 3 displayed a seasonal trend. Although hPIV is an uncommon cause of severe respiratory infecion requiring hospitalization in children, it should be considered in the differential diagnosis of laryngitis, bronchiolitis and pneumonia, especially in younger children.

Human respiratory syncytial virus detection in children admitted at a community hospital in Botucatu, SP, Brazil

O Vírus Respiratório Sincicial Humano (VRSH) é descrito como o mais importante patógeno viral causador de doenças respiratórias agudas das vias respiratórias inferiores em crianças. Neste estudo 84 amostras de crianças com idade abaixo dos dois anos apresentando sintomas de doença respiratória aguda, foram obtidas no período de setembro de 2000 a novembro de 2001. Analise por imunofluorescência indireta e transcrição reversa seguida de PCR, revelou que 18 per center (15/84) das amostras foram positivas, sendo que em 80 per center (12/15) dos casos a detecção de VRSH foi observada em crianças abaixo dos seis meses, e também que os subgrupos A e B co-circularam. Estes são os primeiros dados obtidos para a cidade de Botucatu, sendo que a sazonalidade mostrou-se evidente pela maior circulação desse vírus entre os meses de maio e julho.

Infección extra e intrahospitalaria por virus sincicial respiratorio en lactantes / Extra e intrahospital infection by respiratory syncytial virus in infant

Con el propósito de describir los aspectos clínicos de la infección de la VRS se estudiaron 131 lactantes menores de dos años hospitalizados por infección respiratoria aguda baja en los inviernos de 1988 y 1989 en santiago. Al ingreso se les hizo aspirado nasofaríngeo para inmunofluorescencia anti-VRS, hemograma, velocidad horaria de eritrosedimentación, radiografía de tórax y se consignaron los signos clínicos. 53 de ellos tenían una infección por VRS. La recolección de muestras de aspirado nasofaríngeo día por medio en dos salas de hospitalización permitió detectar 42 casos nososcomiales entre 251 ingresos no infectados originalmente. No se encontraron diferencias en los signos clínicos, hematológicos y radiológicos de ingreso entre casos con y sin VRS. La tasa de infección nosocomial fue 16,7 por ciento; en 76 por ciento de estos casos ella se adquirió durante la primera semana, su frecuencia no fue proporcional a la magnitud del contacto con lactantes excretores de VRS y los afectados no tuvieron mayor estadía hospitalaria que los restantes pacientes. La ausencia de signos diferenciales entre infecciones respiratorias bajas virales y bacterianas hace resaltar la utilidad de los métodos rápidos de diagnóstico para virus en el manejo racional de estas afecciones

Respiratory viruses in the pediatric intensive care unit: prevalence and clinical aspects

A survey was conducted in two pediatric intensive care units in hospitals in Porto Alegre, Brazil, in order to monitor the main respiratory viruses present in bronchiolitis and/or pneumonia and their involvement in the severity of viral respiratory infections. Viral respiratory infection prevalence was 38.7 percent. In bronchiolitis, respiratory syncytial virus (RSV) was detected in 36 percent of the cases. In pneumonia, the prevalence rates were similar for adenovirus (10.3 percent) and RSV (7.7 percent). There was a difference among the viruses detected in terms of frequency of clinical findings indicating greater severity. Frequency of crackles in patients with RSV (47.3 percent) showed a borderline significance (p = 0.055, Fisher's exact test) as compared to those with adenovirus (87.5 percent). The overall case fatality rate in this study was 2.7 percent, and adenovirus showed a significantly higher case fatality rate (25 percent) than RSV (2.8 percent) (p = 0.005). Injected antibiotics were used in 49 percent of the children with RSV and 60 percent of those with adenovirus. Adenovirus was not detected in any of the 33 children submitted to oxygen therapy.