Comparative analysis of SARS-CoV-2 variants Alpha (B.1.1.7), Gamma (P.1), Zeta (P.2) and Delta (B.1.617.2) in Vero-E6 cells: ultrastructural characterization of cytopathology and replication kinetics

Abstract This study compares the effects of virus-cell interactions among SARS-CoV-2 variants of concern (VOCs) isolated in Brazil in 2021, hypothesizing a correlation between cellular alterations and mortality and between viral load and transmissibility. For this purpose, reference isolates of Alpha, Gamma, Zeta, and Delta variants were inoculated into monolayers of Vero-E6 cells. Viral RNA was quantified in cell supernatants by RT‒PCR, and infected cells were analyzed by Transmission Electron Microscopy (TEM) for qualitative and quantitative evaluation of cellular changes 24, 48, and 72 hours postinfection (hpi). Ultrastructural analyses showed that all variants of SARS-CoV-2 altered the structure and function of mitochondria, nucleus, and rough endoplasmic reticulum of cells. Monolayers infected with the Delta variant showed the highest number of modified cells and the greatest statistically significant differences compared to those of other variants. Viral particles were observed in the cytosol and the cell membrane in 100 % of the cells at 48 hpi. Alpha showed the highest mean particle diameter (79 nm), and Gamma and Delta were the smallest (75 nm). Alpha and Gamma had the highest particle frequency per field at 48 hpi, while the same was observed for Zeta and Delta at 72 hpi and 24 hpi, respectively. The cycle threshold of viral RNA varied among the target protein, VOC, and time of infection. The findings presented here demonstrate that all four VOCs evaluated caused ultrastructural changes in Vero-E6 cells, which were more prominent when infection occured with the Delta variant.

Long COVID-19 syndrome associated with Omicron XBB.1.5 infection: a case report

BACKGROUND There is interest in lingering non-specific symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, referred to as Long coronavirus disease 2019 (Long COVID-19). It remains unknown whether the risk of Long COVID-19 is associated with pre-existing comorbidities or initial COVID-19 severity, including infections due to new Omicron lineages which predominated in 2023. OBJECTIVES The aim of this case report was to characterize the clinical features of acute XBB.1.5 infection followed by Long COVID-19. METHODS We followed a 73-year old female resident of Rio de Janeiro with laboratory-confirmed SARS-CoV-2 during acute infection and subsequent months. The SARS-CoV-2 lineage was determined by genome sequencing. FINDINGS The participant denied comorbidities and had completed a two-dose vaccination schedule followed by two booster doses eight months prior to SARS-CoV-2 infection. Primary infection by viral lineage XBB.1.5. was clinically mild, but the participant subsequently reported persistent fatigue. MAIN CONCLUSIONS This case demonstrates that Long COVID-19 may develop even after mild disease due to SARS-CoV-2 in fully vaccinated and boosted individuals without comorbidities. Continued monitoring of new SARS-CoV-2 lineages and associated clinical outcomes is warranted. Measures to prevent infection should continue to be implemented including development of new vaccines and antivirals effective against novel variants.

Molecular diversity of human parvovirus B19 during two outbreaks of erythema infectiosum in Brazil

Abstract This study was conducted to provide information on the genetic diversity of human parvovirus B19 (B19V) circulating in the municipality of Niterói, Rio de Janeiro, Southeast Brazil during 1996-2006, a period with two distinct outbreaks of B19V infection: 1999-2000 and 2004-2005. A total of 27 sera from patients with erythema infectiosum and five sera from HIV-infected patients that tested positive for B19V DNA during the study period were analyzed. To genotype B19V strains, a semi-nested PCR for partial amplification of the capsid gene was performed and sequence analysis revealed that 31 sequences belonged to subgenotype 1a (G1a) of the main genotype 1 and one sequence was characterized as subgenotype 3b (G3b). The phylogenetic tree supported the division of the G1a into two well-defined clades with 1.3% of divergence. The low diversity of the G1a strains may be explained by the fact that all patients had acute B19V infection and 30/32 sera were collected during two distinct outbreaks. The G3b strain was from an HIV-infected patient who seroconverted to anti-B19 IgG antibodies in September/2005. This is the first report of G3b in the state of Rio de Janeiro.

Whole-genome sequences of influenza A(H3N2) viruses isolated from Brazilian patients with mild illness during the 2014 season

The influenza A(H3N2) virus has circulated worldwide for almost five decades and is the dominant subtype in most seasonal influenza epidemics, as occurred in the 2014 season in South America. In this study we evaluate five whole genome sequences of influenza A(H3N2) viruses detected in patients with mild illness collected from January-March 2014. To sequence the genomes, a new generation sequencing (NGS) protocol was performed using the Ion Torrent PGM platform. In addition to analysing the common genes, haemagglutinin, neuraminidase and matrix, our work also comprised internal genes. This was the first report of a whole genome analysis with Brazilian influenza A(H3N2) samples. Considerable amino acid variability was encountered in all gene segments, demonstrating the importance of studying the internal genes. NGS of whole genomes in this study will facilitate deeper virus characterisation, contributing to the improvement of influenza strain surveillance in Brazil.

Oseltamivir-resistant influenza A(H1N1)pdm2009 strains found in Brazil are endowed with permissive mutations, which compensate the loss of fitness imposed by antiviral resistance

The 2009 pandemic influenza A virus outbreak led to the systematic use of the neuraminidase (NA) inhibitor oseltamivir (OST). Consequently, OST-resistant strains, carrying the mutation H275Y, emerged in the years after the pandemics, with a prevalence of 1-2%. Currently, OST-resistant strains have been found in community settings, in untreated individuals. To spread in community settings, H275Y mutants must contain additional mutations, collectively called permissive mutations. We display the permissive mutations in NA of OST-resistant A(H1N1)pdm09 virus found in Brazilian community settings. The NAs from 2013 are phylogenetically distinct from those of 2012, indicating a tendency of positive selection of NAs with better fitness. Some previously predicted permissive mutations, such as V241I and N369K, found in different countries, were also detected in Brazil. Importantly, the change D344N, also predicted to compensate loss of fitness imposed by H275Y mutation, was found in Brazil, but not in other countries in 2013. Our results reinforce the notion that OST-resistant A(H1N1)pdm09 strains with compensatory mutations may arise in an independent fashion, with samples being identified in different states of Brazil and in different countries. Systematic circulation of these viral strains may jeopardise the use of the first line of anti-influenza drugs in the future. (AU)

Molecular findings from influenza A(H1N1)pdm09 detected in patients from a Brazilian equatorial region during the pandemic period

After the World Health Organization officially declared the end of the first pandemic of the XXI century in August 2010, the influenza A(H1N1)pdm09 virus has been disseminated in the human population. In spite of its sustained circulation, very little on phylogenetic data or oseltamivir (OST) resistance is available for the virus in equatorial regions of South America. In order to shed more light on this topic, we analysed the haemagglutinin (HA) and neuraminidase (NA) genes of influenza A(H1N1)pdm09 positive samples collected during the pandemic period in the Pernambuco (PE), a northeastern Brazilian state. Complete HA sequences were compared and amino acid changes were related to clinical outcome. In addition, the H275Y substitution in NA, associated with OST resistance, was investigated by pyrosequencing. Samples from PE were grouped in phylogenetic clades 6 and 7, being clustered together with sequences from South and Southeast Brazil. The D222N/G HA gene mutation, associated with severity, was found in one deceased patient that was pregnant. Additionally, the HA mutation K308E, which appeared in Brazil in 2010 and was only detected worldwide the following year, was identified in samples from hospitalised cases. The resistance marker H275Y was not identified in samples tested. However, broader studies are needed to establish the real frequency of resistance in this Brazilian region.

The epidemiology and antigenic characterization of influenza viruses isolated in Curitiba, South Brazil

Several studies conducted all over the world have reported that the influenza virus is associated with great morbidity and mortality rates. In this study, we analyzed the incidence of the influenza virus between 2000 and 2003 in Curitiba. We studied 1621 samples obtained from outpatients and hospitalized patients of both sexes and all ages. The study was conducted at the local primary care health units (outpatients) and at the tertiary care unit (hospitalized) of the General Hospital of the Federal University in the state of Paraná, Brazil. Nasopharyngeal aspirates and, eventually, bronchoalveolar lavage were assayed for the presence of viral antigens, either by indirect immunofluorescence or cell culture. Of the samples studied, 135 (8.3 percent) were positive for influenza virus, and of those, 103 (76.3 percent) were positive for type A and 32 (23.7 percent) for type B. Additionally, positive samples were analyzed by reverse transcription followed by polymerase chain reaction and subtypes H1 and H3 were identified from this group. A high incidence of positive samples was observed mainly in the months with lower temperatures. Furthermore, outpatients showed a higher incidence of influenza viruses than hospitalized patients.

Antigenic and genomic characterization of adenovirus associated to respiratory infections in children living in Northeast Brazil

From January to December 1998, nasopharyngeal aspirates were obtained from 482 children with acute respiratory infections attended in emergence department and wards of a teaching hospital in the city of Salvador, Brazil. The samples were tested for the presence of adenovirus by isolation in tissue culture and indirect immunofluorescence assay. Eleven adenoviruses were detected by both methods in the same clinical samples. Infections by adenovirus were observed during seven months of the year without association with rainy season. Genome analysis was performed on these 11 isolates. Species C was represented by serotypes 1, 2 and 5. Within species B, only serotype 7 (Ad7) was detected. Two genomic variants of Ad1, two variants of Ad2, one of Ad5, and one of Ad7 (7h) were identified. This is the first study of molecular epidemiology of adenovirus associated to acute respiratory infections in children living in Northeast Brazil, and contributes to a better understanding of adenovirus infections in the country.

A rubella serosurvey in postpartum women in the three regions of Peru

OBJECTIVE: To determine the proportion of postpartum women aged 15-49 in Peru who are susceptible to rubella, in order to help address strategies to eliminate rubella and to prevent congenital rubella syndrome (CRS) in the country. METHODS: A cross-sectional survey was conducted during March and April 2003 in six main regional hospitals, in the three geographic regions (coast, mountain, and jungle) of Peru. For the postpartum women who provided written informed consent, a questionnaire was administered and a blood specimen was collected. Sera were tested for rubella immunoglobulin G (IgG) antibody, using a commercial enzyme-linked immunosorbent serologic assay (ELISA) kit. Univariate, bivariate, and multivariate analyses were carried out to assess risk factors for susceptibility. RESULTS: In total, 1 236 postpartum women were enrolled. The overall proportion of IgG-antibody negative women was 12.8 percent (95 percent confidence interval (CI): 10.9 percent-14.6 percent). Bivariate analysis found the following variables associated with susceptibility: living in the jungle region (odds ratio (OR) = 1.65; 95 percent CI: 1.13-2.42); age < 19 years (OR = 2.02; 95 percent CI: 1.35-3.03); being a housewife (OR = 1.69; 95 percent CI: 1.12-2.55); and having < 11 years of education (OR = 2.12; 95 percent CI :1.20-3.75). Multivariate analysis found the following variables were associated with susceptibility: living in the jungle region (OR = 1.67; 95 percent CI: 1.13-2.46); age < 19 years (OR = 1.62; 95 percent CI: 1.07-2.47); having < 4 children born alive (OR = 1.85; 95 percent CI: 1.00- 3.40); and having < 11 years of education (OR = 2.07; 95 percent CI: 1.16-3.71). CONCLUSIONS: The proportion of postpartum women at the study sites who were found to be susceptible to rubella was 12.8 percent, placing Peru among the countries facing a moderate level of risk for the occurrence of CRS cases. The findings suggest the need to also provide...

OBJETIVO: Determinar la proporción de mujeres recién paridas de 15-49 años de edad susceptibles a la rubéola en Perú, a fin de contribuir a establecer estrategias para eliminar la rubéola y evitar el síndrome de rubéola congénita (SRC) en el país. MÉTODOS: Se realizó un estudio transversal en marzo y abril de 2003 en seis hospitales regionales principales de tres regiones geográficas (costa, sierra y selva) de Perú. A las mujeres recién paridas que dieron su consentimiento informado por escrito se les aplicó un cuestionario y se les tomó una muestra de sangre. La detección serológica de anticuerpos de la clase IgG contra rubéola se realizó mediante un ensayo inmunoenzimático comercial tipo ELISA. Se realizaron análisis con una, dos y múltiples variables para evaluar los factores de riesgo de ser susceptible a la enfermedad. RESULTADOS: En total participaron 1 236 mujeres recién paridas. La proporción de mujeres negativas a anticuerpos IgG contra rubéola fue de 12,8 por ciento (intervalo de confianza de 95 por ciento [IC95 por ciento]: 10,9 por ciento a 14,6 por ciento). Según el análisis bifactorial, las variables asociadas con la vulnerabilidad a la enfermedad fueron: vivir en la región de la selva (razón de posibilidades [odds ratio, OR] = 1,65; IC95 por ciento: 1,13 a 2,42); tener menor de 19 años de edad (OR = 2,02; IC95 por ciento: 1,35 a 3,03); ser ama de casa (OR = 1,69; IC95 por ciento: 1,12 a 2,55); y tener 11 años o menos de educación (OR = 2,12; IC95 por ciento: 1,20 a 3,75). Las variables asociadas con la vulnerabilidad a la enfermedad según el análisis multifactorial fueron: vivir en la región de la selva (OR = 1,67; IC95 por ciento: 1,13 a 2,46); tener menos de 19 años de edad (OR = 1,62; IC95 por ciento: 1,07 a 2,47); tener menos de 4 niños nacidos vivos (OR = 1,85; IC95 por ciento: 1,00 a 3,40); y tener 11 años o menos de educación (OR = 2,07; IC95 por ciento: 1,16 a 3,71). CONCLUSIONES: En la zona estudiada, la proporción...

Prevalence of antibodies against measles, mumps, and rubella before and after vaccination of school-age children with three different triple combined viral vaccines, Rio Grande do Sul, Brazil, 1996

OBJECTIVE: We evaluated the seroprevalence for measles, mumps, and rubella in school-age children (6-12 years old) before and after the administration of three triple combined viral vaccines. METHODS: In two municipal schools of Rio Grande do Sul, Brazil, 692 blood samples were collected before vaccination and 636 samples 21 to 30 days after vaccination during 1996. IgG antibody seropositivity was investigated by enzyme-linked immunosorbent assay (measles and mumps with Enzygnost [Behring, Marburg, Germany]; rubella with Rubenostika [Organon Teknica, Boxtel, the Netherlands]). The vaccines compared were: A: E-Zagreb, L-Zagreb, and Wistar RA 27/3 (Tresivac); B: Moraten, J-Lynn, and Wistar RA 27/3 (M-M-R II); and C: Schwarz, Urabe AM-9, and Wistar RA 27/3 (Trimovax). RESULTS: Before vaccination, 79.2 percent [95 percent confidence interval (CI) = 76.0 percent-82.2 percent] of the samples were positive for measles, 69.4 percent (95 percent CI = 65.8 percent-72.8 percent) for mumps, and 55.4 percent (95 percent CI = 51.6 percent-59.2 percent) for rubella. After vaccination with the A, B, and C vaccines, seropositivity was 100.0 percent, 99.5 percent, and 100.0 percent, respectively for measles; 99.5 percent, 94.5 percent, and 92.0 percent for mumps; and 92.6 percent, 91.3 percent, and 88.6 percent for rubella. CONCLUSIONS: About one-fifth (20.8 percent) of the schoolchildren who could have been vaccinated against measles at age 9 months had levels of antibodies insufficient for protection. In the sample of schoolchildren without previous vaccination against mumps and rubella, high proportions of susceptible levels were found. All vaccines were immunogenic, but vaccine A yielded a seroconversion rate of 99.5 percent for the mumps component, which was significantly higher than the other two vaccines (P < 0.01).

OBJETIVO: Se evaluó la seroprevalencia para sarampión, paperas y rubéola en niños en edad escolar (6-12 años) antes y después de la administración de tres vacunas triples antivirales combinadas. MÉTODOS: Se colectaron 692 muestras de sangre antes de la vacunación y 636 muestras entre 21 y 30 días después de la vacunación a niños de dos escuelas municipales de Rio Grande do Sul, Brasil, durante 1996. Se investigó la seropositividad de anticuerpos de la clase IgG mediante un ensayo de inmunoadsorción enzimática tipo ELISA (sarampión y paperas con Enzygnost [Behring, Marburgo, Alemania] y rubéola con Rubenostika [Organon Teknica, Boxtel, Países Bajos]). Las vacunas comparadas fueron: a) E-Zagreb, L-Zagreb y Wistar RA 27/3 (Tresivac); b) Moraten, J-Lynn y Wistar RA 27/3 (M-M-R II); y c) Schwarz, Urabe AM-9 y Wistar RA 27/3 (Trimovax). RESULTADOS: Antes de la vacunación, 79,2 por ciento (intervalo de confianza [IC] 95 por ciento: 76,0 a 82,2) de las muestras fueron positivas para sarampión, 69,4 por ciento (IC 95 por ciento: 65,8 a 72,8) para paperas y 55,4 por ciento (IC 95 por ciento: 51,6 a 59,2) para rubéola. Después de la vacunación con las vacunas A, B y C, la seropositividad fue de 100 por ciento, 99,5 por ciento y 100 por ciento, respectivamente para sarampión; de 99,5 por ciento, 94,5 por ciento y 92,0 por ciento para paperas; y de 92,6 por ciento, 92,3 por ciento y 88,6 por ciento para rubéola. CONCLUSIONES: Alrededor de un quinto (20,8 por ciento) de los escolares que pudieron haber sido vacunados contra el sarampión a los 9 meses de edad tenían niveles de anticuerpos insuficientes para protegerlos. En la muestra de escolares sin vacunación previa contra paperas y rubéola se encontró una alta proporción de niños susceptibles. Todas las vacunas fueron inmunogénicas, pero la vacuna A produjo una tasa de seroconversión de 99,5 por ciento para el componente de paperas, significativamente mayor que la de las otras dos vacunas (P < 0,01).

Etiologia de exantema em crianças em uma área endêmica de dengue / Etiology of exanthema in children in a dengue endemic area

OBJETIVO: Estudar a etiologia dos casos de exantema com ou sem febre em crianças atendidas no pronto-socorro de um hospital de uma zona endêmica para dengue. MÉTODOS: No período de 21/09/2001 a 20/09/2002, foram inscritas no estudo 95,9 por cento (71/74) das crianças atendidas no pronto-socorro do Hospital Universitário de Campo Grande (MS) que apresentassem exantema (percentual de recusa de 4,1 por cento). Após preenchimento do protocolo com os dados das crianças, as mesmas foram submetidas a exame físico seguido da coleta de amostras de sangue para realizar hemograma com contagem de plaquetas e sorologias (IgM e IgG); inicialmente para dengue, rubéola e toxoplasmose e, posteriormente, naqueles casos com resultado negativo, realizou-se sorologia para parvovirose, herpes vírus tipo 6 e sarampo. RESULTADOS: O diagnóstico laboratorial foi confirmado através da pesquisa de anticorpo IgM em 88,7 por cento dos casos investigados: dengue (77,5 por cento), herpes vírus tipo 6 (8,4 por cento), parvovirose (2,8 por cento) e diagnóstico inconclusivo em oito pacientes (11,3 por cento). Não foi evidenciada sorologia positiva (IgM) para sarampo, rubéola ou toxoplasmose naquela ocasião. As manifestações clínicas mais freqüentes nos pacientes com dengue foram: febre, prurido, prostração, mialgia e prova do laço positiva. Nos pacientes cujo diagnóstico foi dengue, a prova do laço foi positiva em 58,4 por cento (32/55) dos casos, demonstrando diferença estatisticamente significativa quando comparada com o grupo cujo diagnóstico não foi dengue. CONCLUSÕES: Nas crianças com exantema, dengue pode ser a principal enfermidade causal, atentando-se para a epidemiologia do local. É necessário um controle constante da vigilância epidemiológica e sorológica das doenças exantemáticas.

OBJECTIVE: To study the etiology of exanthema cases, with or without fever, in children seen in the emergency room of a hospital located in a region where dengue is endemic. METHODS: Enrollment took place between 21/09/2001 and 20/09/2002 and included 95.9 percent (71/74) of children presenting with exanthema at the emergency room of the Hospital Universitário de Campo Grande, MS (4.1 percent refusals). After the children had had their details taken and entered on the study protocol, they were subjected to physical examination followed by collection of blood samples for blood testing with platelet counts and serology (IgM and IgG); initially for dengue, rubella and toxoplasmosis and then, in negative cases, serology was also run for parvovirus, herpes virus type 6 and measles. RESULTS: Laboratory diagnoses were confirmed by means of IgM antibody assay in 88.7 percent of the cases investigated: dengue (77.5 percent), herpes virus type 6 (8.4 percent), parvovirus (2.8 percent) and in eight patients diagnosis was inconclusive (11.3 percent). On this occasion no positive serology (IgM) was observed for measles, rubella or toxoplasmosis. The most common clinical manifestations among the dengue patients were: fever, itching, prostration, myalgia and positive tourniquet test results. In 58.4 percent (32/55) of those cases diagnosed with dengue, the tourniquet test was positive, which was a statistically significant difference when compared with the remainder of the sample. CONCLUSIONS: When children present with exanthema, it is possible that dengue is the primary causative disease, depending on the epidemiology of the location. Constant control of epidemiological and serological surveillance of exanthematous diseases is necessary.

Seroepidemiological profile of pregnant women after inadvertent rubella vaccination in the state of Rio de Janeiro, Brazil, 2001-2002

OBJETIVOS: Analizar el estado serológico de mujeres embarazadas tras haber recibido inadvertidamente la vacuna antirrubeólica, en el estado de Rio de Janeiro, Brasil. MÉTODOS: Se realizó un estudio transversal de mujeres embarazadas de 15 a 29 años de edad que fueron vacunadas contra la rubéola y el sarampión entre noviembre de 2001 y marzo de 2002 y que no sabían que estaban embarazadas en ese momento o que concibieron en el transcurso de los siguientes 30 días. Se les aplicaron las pruebas detectoras de inmunoglobulina M (IgM) e inmunoglobulina G (IgG) contra el virus de la rubéola y se les clasificó de inmunes si se obtenían resultados negativos a IgM y positivos a IgG al aplicar las pruebas en un lapso no mayor de 30 días después de la vacunación; de susceptibles si se obtenía un resultado positivo a IgM después de la vacunación, o indefinido si se obtenían resultados negativos a IgM y positivos a IgG tras un intervalo mayor de 30 días entre la vacunación y la aplicación de las pruebas serológicas. RESULTADOS: De 2 292 mujeres, 288 (12,6%) se mostraron susceptibles; 316 (13,8%) se mostraron inmunes; 1 576 (68,8%) tuvieron resultados indefinidos; 8 (0,3%) tuvieron resultados ilegibles y 104 (4,5%) no tuvieron seguimiento. La seropositividad a IgM, según el intervalo transcurrido entre la vacunación y la aplicación de las pruebas serológicas, fue de 16,1% (< 30 días), 15,4% (31–60 días), y 14,2% (61–90 días). En lo respectivo a la edad de las personas a las que se dirigió la campaña, se encontró que el grupo de 20 a 24 años tenía la mayor proporción de personas susceptibles a la rubéola (14,8%) y representaba a 42,4% (122/288) de todas las mujeres susceptibles. En 75% de las embarazadas susceptibles, la edad gestacional fue de 5 semanas o menos en el momento de la vacunación. CONCLUSIONES: Se justificó la vacunación poblacional de todas las mujeres en edad fecunda sobre la base de datos epidemiológicos y serológicos. Durante el seguimiento de las embarazadas no se observó ningún caso de síndrome de rubéola congénita ocasionado por la vacuna antirrubeólica. No obstante, el porcentaje de infección congénita observado refuerza la recomendación de que se evite vacunar a mujeres embarazadas y de que estas procuren no concebir durante un mes como mínimo después de la vacunación antirrubeólica.

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.

Serological surveillance of measles in blood donors in Rio de Janeiro, Brazil

OBJETIVOS: Determinar la proporción de personas seronegativas a anticuerpos contra el sarampión entre los donantes de un banco de sangre de la ciudad de Río de Janeiro, Brasil, y describir sus características sociales y demográficas, con el fin de explorar el uso eventual de los bancos de plasma para complementar la vigilancia serológica con datos que permitan apoyar el programa de erradicación del sarampión en la ciudad de Río de Janeiro y en otras localidades. MÉTODOS: Se estudió la presencia de inmunoglobulinas G contra el sarampión en muestras de plasma de 1 101 donaciones de sangre consecutivas realizadas en noviembre de 2000 en HEMORIO, el mayor banco de sangre del estado de Río de Janeiro, mediante un ensayo inmunoenzimático comercial y una prueba de neutralización por reducción de placas. Se calculó la proporción (y el intervalo de confianza (IC) de 95 por ciento) de las muestras negativas a anticuerpos contra el sarampión en la totalidad de las donaciones y en subgrupos conformados según la edad, el sexo, el vecindario de residencia, la educación y la ocupación laboral. La significación estadística de las diferencias entre las proporciones y entre sus tendencias lineales se determinó mediante la prueba de ji al cuadrado. RESULTADOS: Del total de donantes de sangre, el 6,9 por ciento (IC95 por ciento: 5,4 a 8,4 por ciento) resultó seronegativo al sarampión. Las mujeres tuvieron una mayor proporción de resultados seronegativos (10,1 por ciento; IC95 por ciento: 6,8 a 13,4 por ciento) que los hombres (5,6 por ciento; IC95 por ciento: 4,0 a 7,2 por ciento). En relación con la edad, 86,8 por ciento de las personas seronegativas nacieron entre 1971 y 1982. La seronegatividad fue inversamente proporcional a la edad (ji al cuadrado = 58,0; P < 0,0001). En cuanto a la ocupación laboral, los estudiantes presentaron la mayor proporción de seronegativos (17,8 por ciento), mientras que en lo referente a la educación, la mayoría de las personas susceptibles a la enfermedad se encontraban en la categoría de "estudios universitarios incompletos" o "estudios secundarios incompletos". La proporción de seronegativos entre las diferentes áreas de residencia estuvo entre 2,1 por ciento y 11,4 por ciento. CONCLUSIONES: El plasma de los bancos de sangre puede ser una fuente útil y conveniente de datos complementarios para la vigilancia serológica en adultos, tanto de sarampión como de otras enfermedades infecciosas para las que se hayan implementado...

Viral etiology of acute respiratory infections among children in Porto Alegre, RS, Brazil

Although acute respiratory infections (ARIs) are a major cause of child morbidity and mortality in Southern Brazil, little information is available on their seasonality and viral etiology. This study was conducted on children under 5 years of age with ARI to assess viral etiology in the State of Rio Grande do Sul, from 1990 to 1992. A total of 862 nasopharyngeal secretion (NPS) samples were tested using indirect immunofluorescence. The results showed that 316 (36.6) NPS samples were positive: 26.2 for RSV, 6 for adenovirus, 1.7 for influenza viruses, 1.5 for parainfluenza viruses, and 1.2 for mixed infection. The mean viral prevalence rates in out-patient services, emergency wards, and in-patient hospital wards were 26.7, 53 and 42.3, respectively. Respiratory syncytial virus (RSV) and adenovirus accounted for 91.4 of the viral diagnoses. RSV was more frequent in children under one year of age at the three levels of health care and was prevalent in infants under six months. Adenovirus was the most prevalent pathogen in hospitalized children, in 1992. Influenza A virus showed an increased prevalence with age among out-patient children. This study shows the annual occurrence of viral respiratory infections in the coldest months, with a significant annual variation in the frequency of RSV infection.

Pesquisa de anticorpos contra o sarampo em crianças infectadas pelo HIV, após a imunização básica / Search of antimeasles antibodies in HIV-infected children after basic immunization

Objetivo: verificar a presença de anticorpos contra o sarampo em crianças com infecção perinatal pelo HIV e devidamente imunizadas. Métodos: estudo de corte retrospectivo realizado em Belo Horizonte, entre 1995 e 1996. Foram incluídas 21 crianças com infecção perinatal pelo HIV e 29 crianças imunocompetentes não- infectadas. Informações acerca da vacina contra o sarampo foram obtidas do cartão de imunizações dos pacientes. A pesquisa de anticorpos contra o sarampo foi realizada pelos testes de neutralização por redução de placa e dosagem de IgM pela técnica de ELISA. Adotou-se nível de significância de 5por cento em todas as análises estatísticas realizadas. Resultados: a mediana de idade dos pacientes infectados pelo HIV foi de 44,5 meses, e das crianças não-infectadas, de 62,0 meses (p=0,64 ).Os grupos receberam em média 2 doses da vacina contra o sarampo. Todos os pacientes soronegativos para o HIV apresentaram títulos de anticorpos contra o sarampo superiores a 50 mUl/ml, enquanto 57,1por cento das crianças infectadas apresentaram títulos acima deste valor (p=0,0001). O título geométrico médio de anticorpos neutralizantes (GMT) foi significativamente menor no grupo de crianças com infecção pelo HIV(433,5 mUI/ml) do que no grupo de não-fectados(1668,1 mUI/ml), p=0,001. Todos os pacientes dos dois grupos foram negativos para a pesquisa de IgM contra o sarampo. Conclusão: as crianças infectadas pelo HIV apresentaram menor soroprevalência de anticorpos contra o sarampo após a imunização do que as crianças não-infectadas. Esses resultados alertam para o risco potencial de aquisição do vírus do sarampo, e apontam a necessidade de avaliar alternativas para a imunização das crianças infectadas pelo HIV, no sentido de maximizar a proteção contra o sarampo nesse grupo de pacientes

Respiratory syncytial virus groups A and B in Porto Alegre, Brazil, from 1990 to 1995 and 1998

We analyzed the respiratory syncytial virus (RSV) groups and their epidemiological pattern that were detected over the course of seven years in southern Brazil. The two RSV groups co-circulated each year, but frequencies of groups A and B varied both between and within yearly outbreaks. In 1991, group A predominated over group B (p=0.0016). RSV outbreaks analyzed showed a temperature-dependent pattern and no association with rainfall, similarly to other countries from southern South America. Knowledge of the variants is important in terms of both diagnosis and definition of a vaccine composition

Enteroviruses isolated from patients with acute respiratory infections during seven years in Rio de Janeiro (1985-1991)

Os enterovirus foram investigados em secrecoes respiratorias coletadas de pacientes com infeccao respiratoria aguda (IRA), durante um periodo de sete anos (1985-1991), dentro de um estudo longitudinal da etiologia das IRAs. Neste estudo foram encontrados todos os virus que sao mais comumente associados com IRA. Entre os virus isolados, os enterovirus foram apenas menos frequentes que virus respiratorio sincicial, adenovirus e influenzavirus. Quarenta e cinco amostras de enterovirus foram isoladas de pacientes com infeccao do trato respiratorio superior ou inferior. Entre estes enterovirus isolados, trinta e uma amostras foram identificadas como poliovirus (n=18) e enterovirus nao polio (n=13) pelo teste de soroneutralizacao. As amostras de poliovirus isoladas foram classificadas como amostras vacinais do tipo 1 e 2. Dos treze enterovirus nao polio, doze foram identificados como echovirus sorotipos 1, 2, 7, 11, 19 e 31 e apenas um foi identificado como coxsackievirus B4

Genomic characterization of adenovirus serotype 7 isolated in Brazil from acute respiratory disease patients during the period from 1980 to 1991

Quarenta amostras de Adenovirus tipo 7 foram analisadas por digestao com as enzimas de restricao BamHI, SmaI, EcoRI e HindIII. Estas amostras foram coletadas de pacientes apresentando doenca respiratoria aguda durante os anos de 1980 a 1991. Somente dois tipos genomicos foram encontrados: Ad7b e Ad7e, sendo que Ad7b (87,5 por cento) foi mais frequente que Ad7e (12,5 por cento). O tipo genomico Ad7e apareceu nos anos 1980, 1981 e 1983. Ad7b apareceu durante 1982 e seguiu sendo o unico tipo genomico encontrado de 1984 a 1991. Ambos os tipos genomicos foram responsaveis por infeccoes do trato respiratorio superior (ITRS) e inferior (ITRI), porem a proporcao ITRI/ITRS e mais alta para Ad7b (25/6) que para Ad7e (1/4)

Human parvovirus B19 infections among exanthematic diseases notified as measles

A total of 1397 sera collected from 1095 cases of exanthematic disease notified as measles in ES and RJ states during July 1992 to December 1994 were investigated. These sera were first tested for measles and rubella specific IgM. When they proved negative, they were tested for B19 specific IgM by an enzyme immunoassay. B19 infection was confirmed in 27 (2.5 per cent) of these cases. Sera from 194 negative cases for measles and rubella IgM received from other Brazilian states were also investigated and B19 infection was confirmed for 11 of them. Sera from these 38 IgM positive cases for B19, were tested for anti-B19 IgG by an enzyme immunoassay and for B19 DNA by dot blot hybridization. Anti-B19 IgG antibodies were detected in most of the acute sera. B19 DNA was detected in the acute serum of one patient that had been splenectomized before. As the exanthem caused by human parvovirus infection may be clinically diagnosed as rubella, it could be important to diagnose B19 infection in Brazil since it is becoming prevalent as the cause of rash in countries where rubella is controlled by vaccination.