Hemophagocytic Syndrome Secondary to Human Parvovirus B19 Infection in an Acquired Immunodeficiency Syndrome Patient:Report of One Case / 中国医学科学院学报

The acquired immunodeficiency syndrome patients with compromised immunity are prone to hemophagocytic syndrome secondary to opportunistic infections.This paper reports a rare case of hemophagocytic syndrome secondary to human parvovirus B19 infection in an acquired immunodeficiency syndrome patient,and analyzes the clinical characteristics,aiming to improve the diagnosis and treatment of the disease and prevent missed diagnosis and misdiagnosis.

Infección por parvovirus humano B19 en pacientes con enfermedad de células falciformes: a propósito de dos hermanos / Human parvovirus B19 infection in sickle cell disease patients: a two siblings report

Resumen La infección por parvovirus humano B19 es una de las complicaciones comunes en pacientes diagnosticados de enfermedad de células falciformes (ECF). Se caracteriza por una anemia grave con reticulocitopenia, pudiendo estar acompañada de otras manifestaciones clínicas. En ocasiones, la infección puede ocurrir de modo simultáneo en contactos intrafamiliares de un paciente también con ECF. Es fundamental el reconocimiento temprano de esta complicación y el diagnóstico diferencial con otras patologías para su correcto manejo y tratamiento. Presentamos el caso de dos hermanos con ECF e infección por parvovirus humano B19.

Abstract Human parvovirus B19 infection is one of the common complications of patients diagnosed with Sickle cell disease (SCD). Parvovirus infections are characterized by a severe anemia with reticulocytopenia, sometimes presenting with other clinical manifestations. The infection can occur simultaneously in patient's cohabitants also diagnosed with SCD. Early recognition and differential diagnosis are essential for a proper disease management and treatment. We present two siblings with SCD and human parvovirus B19 infection.

Hiperplasia eritroblástica secundaria a infección aguda por parvovirus B19

Resumen La infección aguda por parvovirus B19 es una enfermedad autolimitada en pacientes sin trastornos inmunitarios. Sin embargo, en pacientes con discrasias sanguíneas pueden manifestarse con una crisis aplásica. Presentamos el caso de un varón de 48 años, con una esferocitosis hereditaria no diagnosticada previamente, la cual debutó con una crisis aplásica inducida por una infección aguda de parvovirus B19. La sospecha clínica se planteó luego del análisis histopatológico de la médula ósea, en el que se observó una hiperplasia eritroblástica, con precursores eritroides gigantes e inclusiones nucleares virales, y cuyo análisis inmunohistoquímico fue positivo para la proteína de la cápside viral VP1 y VP2 de parvovirus B19 en células infectadas. Se confirmó la sospecha diagnóstica con la detección de anticuerpos IgM de parvovirus B19. De acuerdo a nuestra revisión, este es el primer reporte de un adulto en Latinoamérica que debutó con una crisis aplásica inducida por una infección aguda por parvovirus B19, como primera manifestación de una esferocitosis hereditaria.

Abstract Acute parvovirus B19 infection is a self-limiting disease in patients with normal immune response. However, in patients with blood dyscrasias, it is possible to present with an aplastic crisis. We present the case of a 48-year-old man who had developed an aplastic crisis as a result of an acute parvovirus B19 infection with an undiagnosed hereditary spherocytosis. Suspicions of the parvovirus infection began to arise after a routine bone marrow histopathological analysis which showed erythroblastic hyperplasia with giant erythroid precursor and viral inclusions. A subsequent immunohistochemical analysis tested positive for VP1 and VP2 capsid proteins of parvovirus B19 in infected cells. The diagnostic suspicion was later confirmed with the presence of anti-parvovirus B19 IgM. According to our review, this is the first published case in Latin America that documents an adult patient with normal immune response whose first symptom of hereditary spherocytosis was an aplastic crisis induced by an acute parvovirus B19 infection.

Infecção por parvovírus B19 em receptores de transplante renal: série de caso / Parvovirus B19 infection in kidney transplant recipients: a case series

Os receptores de transplante renal são mais suscetíveis a infecções, entre elas o parvovírus B19, que pode ser transmitido por via respiratória, adquirido por meio do enxerto ou por reativação de infecção latente. A anemia normocítica normocrômica, com diminuição dos reticulócitos e resistência ao tratamento com eritropoietina, é a principal forma de apresentação da infecção por parvovírus B19 em transplante renal. O diagnóstico requer alto índice de suspeição clínica e realização de testes diagnósticos selecionados. Tratamento com imunoglobulina e suspensão dos imunossupressores durante a infecção mostraram-se eficazes. Os autores relatam sua experiência com cinco casos de infecção por parvovírus B19 em receptores de transplante renal de um hospital universitário. Os aspectos clínicos, diagnósticos e terapêuticos são revistos.

Kidney transplant recipients are more susceptible to infections, including by parvovirus B19, spread through the respiratory tract, acquired through the graft or reactivation of latent infection. Normocytic normochromic anemia, with decreased reticulocytes and resistance to erythropoietin treatment, is the most common presentation of Parvovirus B19 infection in renal transplant. Diagnosis requires a higher clinical suspicion and the performance of selected diagnostic tests. Treatment with immunoglobulin and suspension of immunosuppressive therapy during the infection may be effective. The authors report five cases of PB19 infection in kidney transplant patients at a hospital. The clinical, diagnostic, and treatment features are reviewed.

Human parvovirus B19 genotype 1 in suspected dengue patients of Tefé, Amazonas State, Brazil

Abstract INTRODUCTION: Human parvovirus B19 (B19V) is a common pathogen, which on infection causes variety of clinical conditions from benign self-limiting exanthematous disease and other similar pathologies to fetal death. METHODS: We collected 341 serum samples between the first and fourth day after the onset of symptoms from all patients suspected of dengue fever who were attended at Regional Hospital of Tefé. Initially, patients were screened for malaria by blood smear test and negative samples were sent to Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD) situated in Manaus (AM) for dengue testing using semi-nested multiplex PCR. Further, we investigated 44 malaria and dengue-negative samples of children for B19V DNA by nested-PCR. Positive samples were analyzed by BLAST against entire public non-redundant nucleotide database and genotyped by phylogenetic analyses using neighbor-joining clustering method. RESULTS: Eight samples (18.2%) were found to be PCR positive. Fever, headache, ocular pain, and/or muscle pain were reported as the most frequent symptoms by the patients and none were diagnosed with rash at the time of sample collection. Phylogenetic analysis of major capsid protein 2 (VP2) and VP3 coding region showed high similarity with B19V genotype 1. CONCLUSIONS: Our results reveal the spread of B19V genotype 1 in Tefé. Moreover, our results emphasize the significance of laboratorial differential diagnosis using molecular techniques in patients with acute febrile, and thereby aid the health surveillance system in improving patient care even in the remote areas of Amazon.

Serological and molecular analysis of parvovirus B19 infection in Mayan women with systemic lupus erythematosus in Mexico / Análisis serológico y molecular de la infección por parvovirus B19 en mujeres mayas con lupus eritematoso sistémico en México

Abstract Background: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that mainly affects women, characterized by the production of autoantibodies. Its causal agent is unknown, but the combination of environmental, hormonal and genetic factors may favor the development of the disease. Parvovirus B19 has been associated with the development of SLE, since it induces the production of anti-single stranded DNA antibodies. It is unknown whether PV-B19 infection is an environmental factor that trigger or reactivate SLE in the Mexican Mayan population. Aim: A preliminary serological and molecular study of PV-B19 infection in Mayan women with established SLE was done. Methods: IgG and IgM anti PV-B19 were evaluated in 66 SLE patients and 66 control subjects, all women of Mayan origin. Viral DNA and viral load were analyzed by qPCR. Results: Insignificant levels of IgM were observed in 14.3% (4/28) of the patients and 11.4% (4/35) of control subjects. IgG was detected in 82.1% (23/28) of the patients and 82.9% (29/35) of control subjects, but were significantly higher in patients. Viral DNA was found in 86.0% (57/66) of the patients and 81.0% (54/66) of control subjects. Viral load, quantified in 28/66 patients and 31/66 controls which were positive for IgM and IgG, was significantly higher in controls. Conclusion: The high prevalence of PV-B19 in Yucatan, and the presence of IgM, IgG, and viral load in Mayan women with established SLE suggest that PV-B19 infection could be an environmental factor to trigger or reactivate SLE.

Resumen Antecedentes: Lupus eritematoso sistémico (LES) es una enfermedad sistemica autoinmune que afecta principalmente a las mujeres, caracterizada por la producción de autoanticuerpos. El agente causaal es desconocido. Pero la combinación de factores ambientales, hormonales y genéticos podría favorecer el desarrollo de la enfermedad. El parvovirus B19 se asoció con el desarrollo de LES, debido a que induce la producción de anticuerpos anti-cadena simple de DNA. Es desconocido si la infección PV-B19 es un factor ambiental que desencadena o reactiva LES en la población mexicana Maya. Objetivo: Se realizó un estudio serológico y molecular preliminar de la infección de PV-B19 en mujeres Mayas con LES. Métodos: Se evaluó IgG and IgM anti PV-B19 en 66 pacientes con LES y 66 controles sanos, todas las mujeres fueron de origen Maya. DNAViral y la carga viral fueron analizadas por qPCR. Resultados: Se determinaron niveles insignificantes de IgM en el 14.3% (4/28) de las pacientes y en el 11.4% (4/35) de los controles. IgG se detectó en el 82.1% (23/28) de los pacients y en el 82.9% (29/35) de los controles. Hubo un alta significancia en los pacientes con LES. DNA viral se encontró en el 86.0% (57/66) de los pacientes y en el 81.0% (54/66) de los controles. La carga viral se cuantifico en 28/66 pacientes y en 31/66 de los controles, la cual fueron positivos para IgM e IgG; fue significativamente mas alta en los controles. Conclusión: La alta prevalencia de PV-B19 en Yucatan y la presencia de IgM, IgG y una carga viral en mujeres Mayas con LES sugiere que la infección con PV-B19 poria ser un factor ambiental que desencadene o reactive el LES

Estudio de marcadores de infección e inmunidad frente a parvovirus B19 en Córdoba, Argentina

RESUMEN: El parvovirus B19 (B19V), descubierto en 1974, es un patógeno humano de distribución global. Si bien su infección puede transcurrir de manera asintomática, es conocido por ser capaz de causar un amplio espectro de manifestaciones clínicas como son el eritema infeccioso, artropatías, crisis aplásica en individuos con recambio acelerado de glóbulos rojos por una enfermedad de base, y anemia crónica en inmunocomprometidos, entre otras patologías en las que aún se investiga la causalidad del B19V. La infección durante el embarazo es un riesgo potencial para el feto...

ABSTRACT: Parvovirus B19 (B19V), discovered in 1974, is a pathogen of global distribution. While the infection can be asymptomatic, it is known for being able to cause a wide range of clinical manifestations such as erythema infectiosum (or fitth disease), arthropathy, aplastic crisis in persons with accelerated red blood cell renewal due to a base disease, and chronic anemia in immunocompromised individuals, among other pathologies inwhich B19V causality is still under research. In addition, infection during pregnancy is a potential risk for the fetus...

Circulación de Bocavirusen niños menores de 5 años con infección respiratoria aguda de la provincia del Chaco: análisis de los años 2014 y 2015 / Bocavirus circulation in children under 5 years with acute respiratory infection in the province of Chaco: analysis of 2014 and 2015

Acute respiratory infection (ARI) is the most frequent pathology along human life, being the most common cause of morbidity and mortality in children under 5 years old. The aim of this study was to determine the circulation of HBoV in infants under 5 years old with symptoms of ARI from north Argentina (Chaco province). Were analyzed 882 nasopharyngeal aspirates obtained during the years 2014 and 2015. The samples were tested by real time PCR and the overal frequency of HBoV was 7.6%. The period with the major detection report was June-September with 77.6% of all positive cases. It is interesting that 98.5% of all cases were in infants aged 0 to 2 years of life. HBoV positive cases were given as single infection in 46.3% of patients and the remaining 53.7% as concomitant infections with other viruses. The evaluation of two full years calendar of molecular epidemiological study in northern Argentina of HBoV, reflects more accurately the current situation and could lead to re-formulate strategies for diagnosis, treatment and prognosis of this disease. We intend to highlight the importance of investigate this new virus capable of produce an acute respiratory disease by providing information about it to the community.

A infecção respiratória aguda (IRA) é a mais frequente ao longo da vida de uma patologia individual e é a causa mais comum de mortalidade/morbidade em crianças com menos de 5 anos. O objetivo deste estudo foi determinar o movimento do Bocavírus Humano (HBoV) em crianças menores de 5 anos com um diagnóstico presuntivo de IRA numa capital estadual do norte da Argentina (Resistencia, Chaco). Foram analizados 882 aspirados nasofaríngeos, obtidos durante os anos 2014 e 2015. As pessoas foram testeadas por PCR em tempo real, onde se encontrou uma frequência de HBoV do 7,6% (67/882), dando a maior concentração de casos positivos no período de junho a setembro (77,6%). Curiosamente, 98,5% dos casos foram em crianças de 0 a 2 anos de vida. Os casos positívos de HBoV foram dados como única infecção em 46,3% dos pacientes e os restantes 53,7% como infecções concomitantes com outros vírus. A avaliação de dois anos, calendário completo de estudo de epidemiologia molecular HBoV no norte da Argentina, reflete com mais precisão a realidade, e pode reformular as estratégias para o diagnóstico, tratamento e prognóstico da patología. Temos a intenção de destacar a importância de se investigar o novo vírus capaz de gerar doença respiratória aguda, fornecendo informações dele para a comunidade

La infección respiratoria aguda (IRA) es la patología más frecuente a lo largo de la vida de una persona y es la causa más común de morbi-motalidad en niños menores de 5 años. El objetivo de este trabajo fue determinar la circulación del Bocavirus Humano (HBoV) en niños menores de 5 años con diagnóstico presuntivo de IRA en una ciudad capital del norte argentino (Resistencia, Chaco). Ruiz Díaz, Natalia; y Col. Rev. Fac. Med. UNNE XXXVI: 3, 5-12, 2016 Se analizaron 882 aspirados nasofaríngeos obtenidos durante los años 2014 y 2015. Los mismos fueron testeados por PCR en tiempo real encontrándose una frecuencia de HBoV de 7.6% (67/882), dándose la mayor concentración de casos positivos en el período junio-septiembre (77,6%) y es interesante destacar que el 98,5% del total de casos se registraron en infantes entre 0 a 2 año de vida. Los casos positivos para HBoV se dieron como infección única en el 46.3% de los pacientes y el 53.7% restante como infecciones concomitantes con otros virus. La evaluación de dos años -calendarios completos- de estudio epidemiológico molecular de HBoV en el norte argentino, refleja de manera más fiel la realidad ya que permite reformular las estrategias en cuanto al diagnóstico, el tratamiento y el pronóstico de esta patología. Pretendemos destacar la importancia de investigar los nuevos virus capaces de generar patología respiratoria aguda brindando información sobre el mismo a la comunidad

Frequency of human bocavirus respiratory infections among at-risk patients in São Paulo, Brazil / Frequência de bocavírus humano em infecções respiratórias entre pacientes de risco na cidade de São Paulo, Brasil

BACKGROUND AND OBJECTIVES: Human Bocavirus (HBoV) has been described since 2005 as an etiological agent of respiratory virus infections. From 2001 to 2008 we investigated the etiology of HBoV among adults and children in different groups at risk of presenting complications arising from acute respiratory infection, the investigation was carried out in a tertiary hospital health care system in Brazil. METHODS: HBoV DNA was assayed in 598 respiratory samples from community and hospitalized patients by PCR. RESULTS: Of the 598 tested samples, 2.44% (8/328) of children, including five children with heart disease, and 0.4% (1/270) of adult bone-marrow-transplant were HBoV positive. CONCLUSIONS: These data suggested lower HBoV frequency among different at-risk patients and highlights the need to better understand the real role of HBoV among acute respiratory symptomatic patients.

INTRODUÇÃO E OBJETIVOS: O bocavírus humano (HBoV) tem sido descrito desde 2005 como agente etiológico de infecções respiratórias virais. O presente estudo tem como objetivo investigar a etiologia da infecção respiratória pelo HBoV em pacientes adultos e crianças de diferentes grupos de risco para complicação de infecções respiratórias agudas desde 2001 até 2008 em um hospital terciário no Brasil. PACIENTES E MÉTODOS: O HBoV foi investigado, através de reação em cadeia da polimerase, em 598 amostras respiratórias coletadas de pacientes hospitalizados e não hospitalizados. RESULTADOS: Das 598 amostras testadas o HBoV foi detectado em 2,44% (8/328) das crianças, incluindo cinco crianças portadoras de cardiopatia congênita, e 0,4% (1/270) dos adultos em programa de transplante de células tronco hematopoiéticas. CONCLUSÃO: Os dados do presente estudo sugerem baixa freqüência de detecção do HBoV entre pacientes de risco, e destaca a necessidade de novos estudos para um melhor entendimento do verdadeiro papel desse agente em infecções respiratórias agudas em pacientes sintomáticos.

Bocavirus humano en Chile: características clínicas y epidemiológicas en niños con infecciones respiratorias / Human bocavirus in Chile: clinical characteristics and epidemiological profile in children with acute respiratory tract infections

Background: Human bocavirus (HBoV) is a newly discovered parvovirus found in children with acute respiratory tract infections (ARTI). Objectives: To describe the epidemiological and clinical profile of children < 5 years old consulting for ARTI, comparing cases of HBoV monoinfection and coinfection with other known respiratory viruses. Furthermore, we aimed to estimate the prevalence of viral shedding in asymptomatic children and perform phylogenetic analysis. Patients and Methods: We investigated the presence of HBoV in nasopharyngeal secretions from children consulting for AlRTI and among asymptomatic controls, between 2007 and 2008, by polymerase chain reaction. Results: HBoV was detected in 79 (21.8 percent) of 362 nasopharyngeal swabs obtained from children with ARTI. In 60/79 (76 percent), coinfection with other respiratory viruses was confirmed. Most common symptoms were cough, fever and rhinorrhea. Children infected only with HBoV showed significantly lower frequencies of respiratory distress, oxygen requirements and hospital admission than those with coinfection. HBoV was detected in 6/16 (37.5 percent) samples from asymptomatic children. The phylogenetic analysis of viruses from Chilean patients revealed that circulating HBoV was closely related to original strains. Conclusions: HBoV was found either in symptomatic and asymptomatic children. The severity of the disease was greater when HBoV was associated to other respiratory viruses.

Introducción: Bocavirus humano (HBoV) es un nuevo parvovirus encontrado en niños con infecciones respiratorias agudas (IRA). Objetivos: Describir la epidemiología y perfil clínico en niños < 5 años con IRA, comparando aquellos con HBoV como único agente identificado, con los que tenían co-infección con otro virus respiratorio. Además se evaluó su prevalencia en niños asintomáticos, y se realizó análisis filogenético. Materiales y Métodos: Se investigó la presencia de HBoV, por medio de reacción de polimerasa en cadena, en muestras de secreción nasofaríngea obtenida en niños con IRA y en controles asintomáticos, entre 2007 y 2008. Resultados: Se detectó HBoV en 79 (21,8 por ciento) de 362 muestras obtenidas en pacientes con IRA. En 60/79 (76 por ciento), se demostró co-infección. Los síntomas más frecuentes fueron tos, fiebre y rinorrea. Los pacientes con HBoV como único agente identificado mostraron frecuencias significativamente menores de dificultad respiratoria, requerimiento de oxígeno y hospitalización, comparado con los co-infectados. HBoV se detectó en 6/16 (37,5 por ciento) muestras de niños asintomáticos. El análisis filogenético de las cepas chilenas demuestra estrecha relación con las cepas originales. Conclusiones: HBoV está presente en niños chilenos con IRA y asintomáticos. La gravedad de la enfermedad fue mayor en el grupo con co-infección.

Adult Reye-like syndrome associated with serologic evidence of acute parvovirus B19 infection

Reye's syndrome is an infrequently diagnosed medical condition affecting mainly children. The etiology, epidemiology and natural history of Reye's syndrome have been cloudily written in footnotes of medical books and exotic papers since the initial description in early 1950s. We report here a case of adult Reye's syndrome associated with serologic evidence of parvovirus B19 infection.

Parvovirus B19 presenting with persistent pancytopenia in a patient of T-ALL post induction chemotherapy diagnosed on bone marrow examination.

Manifestations of parvovirus B19 vary even in the normal host from asymptomatic or subclinical infection to a spectrum of illness with symptoms during viremic and immune complex mediated stage of disease. We report the morphological findings of parvovirus B19 infection (confirmed on serology) in a patient of T-acute lymphoblastic lymphoma (T-ALL) who underwent induction phase of chemotherapy (MCP 842 protocol). Persistent pancytopenia in the bone marrow aspirate with mild increase in blasts was thought to be due to failure to achieve marrow remission. However, giant pronormoblasts with prominent intranuclear inclusions confirmed on trephine biopsy led to the suspicion of parvovirus B19 infection which was later confirmed on serology. This case is presented to report the rarely seen classical morphological feature of parvovirus infection on bone marrow examination which was incidentally the first investigation to diagnose the viremic phase of the infection, indicating that a high index of suspicion needs to be kept in mind while examining bone marrows of susceptible patients.

Detección de ADN de parvovirus B19 en donantes de sangre de tres hospitales en Santiago, Chile / Parvovirus B19 among blood donors from three hospitals in Santiago, Chile

Background: Parvovirus B19 (B19) is associated with a wide range of diseases in humans, whose severity depends on the immunological and hematological status of the host. It is transmitted mainly through the airway but also by transfusions. Aim: To determine the B19 DNA carrier frequency in a population of volunteer blood donors from three hospitals blood banks in Santiago, Chile, and to determine the viral load in DNA positive cases. Material and Methods: A total of477 serum samples were analyzed. The screening of B19 DNA was carried out by nested polymerase chain reaction (PCR) directed to the non-structural region of the virus (NS1). The viral load in positives cases was quantified by NS1 Real Time PCR. Results: Parvovirus B19 was detected in four samples, rendering a frequency of 1:119. The viral loads ranged from less than 2000 to 5,626 x 10(5) genome equivalents/ml. Conclusions: Parvovirus B19 was present in four of 477 blood bank blood donors from three hospitals in Santiago.

Human Bocavirus in Patients with Respiratory Tract Infection / 대한진단검사의학회지

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.

Human Bocavirus in Patients with Respiratory Tract Infection / 대한진단검사의학회지

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.

Investigation of measles IgM-seropositive cases of febrile rash illnesses in the absence of documented measles virus transmission, State of São Paulo, Brazil, 2000-2004 / Investigação dos casos de doenças febris exantemáticas com IgM reagente contra o sarampo na ausência de transmissão documentada do vírus do sarampo, Estado de São Paulo, 2000-2004

INTRODUCTION: To review measles IgM-positive cases of febrile rash illnesses in the State of São Paulo, Brazil, over the five-year period following interruption of measles virus transmission. METHODS: We reviewed 463 measles IgM-positive cases of febrile rash illness in the State of São Paulo, from 2000 to 2004. Individuals vaccinated against measles < 56 days prior to specimen collection were considered to be exposed to the vaccine. Serum from the acute and convalescent phases was tested for evidence of measles, rubella, parvovirus B19 and human herpes virus-6 infection. In the absence of seroconversion to measles immunoglobulin-G, measles IgM-positive cases were considered false positives in individuals with evidence of other viral infections. RESULTS: Among the 463 individuals with febrile rash illness who tested positive for measles IgM antibodies during the period, 297 (64 percent) were classified as exposed to the vaccine. Among the 166 cases that were not exposed to the vaccine, 109 (66 percent) were considered false positives based on the absence of seroconversion, among which 21 (13 percent) had evidence of rubella virus infection, 49 (30 percent) parvovirus B19 and 28 (17 percent) human herpes virus-6 infection. CONCLUSIONS: Following the interruption of measles virus transmission, thorough investigation of measles IgM-positive cases is required, especially among cases not exposed to the vaccine. Laboratory testing for etiologies of febrile rash illness aids interpretation of these cases.

INTRODUÇÃO: Revisar os casos de doenças febris exantemáticas com IgM reagente contra o sarampo, no Estado de São Paulo, Brasil, durante os cinco anos seguidos a interrupção da transmissão do vírus do sarampo. MÉTODOS: Nós revisamos 463 casos de doenças febris exantemáticas com IgM reagente contra o sarampo, no Estado de São Paulo, Brasil, de 2000 a 2004. Indivíduos vacinados contra o sarampo 56 dias antes da coleta de amostra foram considerados expostos à vacina. Soros da fase aguda e de convalescença foram testados para a evidência de infecção de sarampo, rubéola, parvovírus B19 e herpes vírus 6. Na ausência de soroconversão para imunoglobulina G contra o sarampo, casos com IgM reagente contra o sarampo foram considerados falsos positivos em pessoas com evidência de outras infecções virais. RESULTADOS: Entre as 463 pessoas com doenças febris exantemáticas que testaram positivo para anticorpos IgM contra o sarampo durante o período, 297 (64 por cento) pessoas foram classificadas como expostas à vacina. Entre os 166 casos não expostos à vacina, 109 (66 por cento) foram considerados falsos positivos baseado na ausência de soroconversão, dos quais 21 (13 por cento) tiveram evidência de infecção por vírus da rubéola, 49 (30 por cento) parvovírus B19 e 28 (17 por cento) infecção por herpes vírus humano 6. CONCLUSÕES: Após a interrupção da transmissão do vírus do sarampo é necessária exaustiva investigação dos casos com IgM reagente contra o sarampo, especialmente dos casos não expostos à vacina. Testes laboratoriais para etiologias das doenças febris exantemáticas ajudam na interpretação destes casos.

Seroepidemiological study of human parvovirus B19 among human immunodeficiency virus-infected patients in a medium-sized city in Rio de Janeiro, Brazil

Parvovirus B19 (B-19) may cause chronic anaemia in immunosuppressed patients, including those infected with human immunodeficiency virus (HIV). We studied single serum samples from 261 consecutive HIV-infected patients using an enzyme immunoassay to detect IgG antibodies to B-19. The seroprevalence of B-19-IgG was 62.8 percent. The differences in seroprevalence across gender, age, educational categories, year of collection of the serum samples, clinical and antiretroviral therapy characteristics, CD4+ count, CD4+ and CD8+ percentage and CD4+/CD8+ ratios were neither substantial nor statistically significant. There was a non-significant, inverse association between B-19 seropositivity and plasma HIV load and haemoglobin level. Our results indicated that 37.1 percent of patients might be susceptible to B-19 infection and remained at risk for being infected, mainly during epidemic periods. As B-19 infection can be treated with immune globulin preparations, it may be included in the diagnostic approach toward chronic anaemia in HIV-infected patients.

Influence of amplicon size on the polymerase chain reaction of Parvovirus B19 genome in formalin-fixed specimens / Influência do tamanho do amplicon na reação em cadeia da polimerase na detecção do genoma do PB19 em amostras fixadas em formalina

The polymerase chain reaction (PCR) has provided diagnosis of archival material, but some fixation methods such as formalin damage DNA and, subsequently, affect PCR analysis, particularly paraffin-embedded tissues. PCR is known due to its high specificity and sensitivity, although some difficulties arise when formalinfixed and paraffin-embedded tissue is used. Not only does this occur due to protein cross-linking, which increases with longer fixation time, but it also happens due to the direct damage that formalin causes in the DNA itself. PCR was used to analyze placenta and fetal organs from 34 samples with suspected Parvovirus B19 infection. It was not possible to amplify Parvovirus B19 DNA using nested-PCR, probably due to the size of the amplicon generated with the first set of primers. We approached this problem by using only the second set of primers. Two out of 34 tissue samples (5,9 percent) were positive by PCR. However, PCR performed on corresponding fetal organs was negative in one of the two. We also observed a negative relation between the thickness of the tissue fragment and the positivity of the samples. In conclusion, although PCR is highly specific and sensitive in fresh or ideally fixed material, a careful standardization of PCR assays is necessary when using formalin fixed paraffin-embedded tissues by applying primers that require smaller DNA fragments for amplification.

A reação em cadeia da polimerase (PCR) tem fornecido diagnóstico de material de arquivo, mas alguns métodos de fixação, tais como formalina, provocam danos ao DNA e subsequentemente afetam sua análise, particularmente tecidos embebidos em parafina. A PCR é conhecida pela sua alta especificidade e sensibilidade, embora algumas dificuldades ocorram quando o material utilizado foi fixado em formalina e embebido em parafina. Isso não se deve somente pela formação de cross-linkings com proteínas, a qual aumenta com o maior tempo de fixação, mas também pelo dano direto que a formalina causa no DNA. PCR foi usada para analisar placenta e órgão fetais de 34 amostras com suspeita de infecção pelo Parvovírus B19 (PB19). Não foi possível amplificar o DNA do PB19 usando nested-PCR, provavelmente devido ao tamanho do amplicon gerado com o primeiro passo dos primers. Adequamos o problema utilizando somente o segundo par de primers e pudemos observar que das 34 amostras, duas eram positivas para PCR (5,9 por cento). Entretanto, a PCR dos órgãos fetais foi negativa em um de dois casos. Observamos também uma relação negativa entre a espessura do corte dos materiais com a positividade das amostras. Em conclusão, embora a PCR seja altamente específica e sensível em amostras a fresco ou idealmente fixadas, uma padronização cuidadosa para análise com a PCR é necessária quando se utiliza tecidos fixados em formalina e embebidos em parafina utilizando primers que requerem menor fragmento de DNA para a amplificação.

Detection of human parvovirus B19 in cases of hydrops fetalis in São Paulo, Brazil / Detecção de parvovírus humano B19 em casos de hydropsia fetal em São Paulo, Brasil

Human parvovirus B19 infection is known to be one of the causes of hydrops fetalis. The maternal infection caused by the virus may be symptomatic or asymptomatic. In this study, 40 pregnant women with gestational age of approximately 25 weeks, prenatal diagnosis of non immune hydrops fetalis and suspected of human parvovirus B19 infection were studied between January 1999 and December 2005. Serology results and detection of DNA in the maternal serum, foetal serum and amniotic fluid confirmed that 20 pregnant women had been infected by human parvovirus B19. The ultrasound examination demonstrated foetal hydrops, anaemia, hepatosplenomegaly, ascites, cardiopathy and amniotic fluid disorders. Among the positive cases, there were three fatal losses, one by miscarriage and two by intrauterine foetal death.

A infecção por parvovírus humano B19 é um dos responsáveis pela hidropsia fetal. A infecção materna causada pelo vírus pode ser sintomática ou assintomática. Neste estudo 40 mulheres com idade gestacional de aproximadamente 25 semanas, diagnóstico pré-natal de hidropsia fetal e suspeita de infecção por parvovírus humano B19 foram avaliadas durante o período de janeiro de 1999 a dezembro de 2005. Os resultados de sorologia e detecção de DNA no soro materno, fetal e fluido amniótico confirmaram 20 mulheres grávidas com infecção por parvovírus humano B19. A análise de ultra-som demonstrou hidropsia fetal, anemia, hepatosplenomegalia, ascite, cardiopatia e desordens amnióticas. Entre os casos positivos, ocorreram três perdas fetais: uma por aborto e duas por morte fetal intra-uterina.