Acute respiratory viral infections in children in Rio de Janeiro and Teresópolis, Brazil / Infecções respiratórias agudas causadas por vírus em crianças do Rio de Janeiro e de Teresópolis, Brasil

The frequency of viral pathogens causing respiratory infections in children in the cities of Rio de Janeiro and Teresópolis was investigated. Nasal swabs from children with acute respiratory illnesses were collected between March 2006 and October 2007. Specimens were tested for viral detection by conventional (RT)-PCR and/or real time PCR. Of the 205 nasal swabs tested, 64 (31.2%) were positive for at least one of the viral pathogens. Single infections were detected in 56 samples, 50 of those were caused by RNA viruses: 33 samples tested positive for rhinovirus, five for influenza A, five for metapneumovirus, four for coronavirus and, three for respiratory syncytial virus. For the DNA viruses, five samples were positive for bocavirus and one for adenovirus. Co-infections with these viruses were detected in eight samples. Our data demonstrate a high frequency of viral respiratory infections, emphasizing the need for a more accurate diagnosis particularly for the emerging respiratory viruses. The fact that the emerging respiratory viruses were present in 9.2% of the tested samples suggests that these viruses could be important respiratory pathogens in the country.

Neste estudo foi investigada a frequência de patógenos virais causando infecção em crianças nas cidades do Rio de Janeiro e Teresópolis. Foram coletados 205 swabs nasais de crianças com infecção aguda do trato respiratório no período de março de 2006 a outubro de 2007. Os espécimes foram testados para detecção de vírus através de (RT)-PCR e/ou PCR em tempo real. Dentre as 205 amostras testadas, 64 (31,2%) foram positivas para pelo menos um vírus. Infecções causadas por um único agente viral foram detectadas em 56 amostras, 50 das quais eram causadas por vírus de RNA: 33 amostras foram positivas para rinovírus, cinco amostras foram positivas para influenza A, cinco amostras foram positivas para metapneumovírus, quatro amostras foram positivas para coronavírus e três amostras foram positivas para vírus respiratório sincicial. Para os vírus de DNA foram detectadas cinco amostras positivas para bocavírus humano e uma amostra positiva para adenovírus. Foram identificados oito casos de co-infecção. Nossos dados demonstram frequência elevada de infecções respiratórias virais, enfatizando a necessidade de um diagnóstico mais acurado destes patógenos, principalmente os vírus considerados emergentes. O fato de alguns vírus respiratórios emergentes terem sido detectados em 9,2% das amostras testadas sugere que estes vírus podem ser patógenos respiratórios importantes no país.

Acute respiratory viral infections in children in Rio de Janeiro and Teresópolis, Brazil.

The frequency of viral pathogens causing respiratory infections in children in the cities of Rio de Janeiro and Teresópolis was investigated. Nasal swabs from children with acute respiratory illnesses were collected between March 2006 and October 2007. Specimens were tested for viral detection by conventional (RT)-PCR and/or real time PCR. Of the 205 nasal swabs tested, 64 (31.2%) were positive for at least one of the viral pathogens. Single infections were detected in 56 samples, 50 of those were caused by RNA viruses: 33 samples tested positive for rhinovirus, five for influenza A, five for metapneumovirus, four for coronavirus and, three for respiratory syncytial virus. For the DNA viruses, five samples were positive for bocavirus and one for adenovirus. Co-infections with these viruses were detected in eight samples. Our data demonstrate a high frequency of viral respiratory infections, emphasizing the need for a more accurate diagnosis particularly for the emerging respiratory viruses. The fact that the emerging respiratory viruses were present in 9.2% of the tested samples suggests that these viruses could be important respiratory pathogens in the country.

Human bocavirus species 2 and 3 in Brazil.

BACKGROUND: The newly described human bocavirus (HBoV) species 2 and 3 have been repeatedly detected in stool strengthening the possibility that these viruses might present a tropism for the gastrointestinal tract and may be etiological agents of diarrhea. OBJECTIVE: In this study we assessed the presence of HBoV2 and HBoV3 in stool specimens from Brazilians with acute gastroenteritis. STUDY DESIGN: Stool samples from Brazilian patients with acute diarrhea were analyzed for HBoV2 and HBoV3 by PCR assay. Full or partial genome sequences were obtained for selected isolates. Electron microscopy analysis was used to investigate virus morphology. RESULTS: Electron microscopy confirmed the presence of virus-like particles in HBoV PCR-positive specimens, with morphology similar to other members of the Parvoviridae family. Five samples out of 807 (0.6%) were positive for HBoV3. Three of the HBoV3-positive patients were HIV/AIDS positive. A selected group of 144 samples was also tested for HBoV2 and 30 samples (20.8%) were positive, 11 of which were HIV/AIDS positive. CONCLUSION: This study reports the detection and genetic characterization of HBoV3 and HBoV2 in the stool of Brazilian patients with acute diarrhea. This is the first description of HBoV3 outside Australia, suggesting a wide global distribution of this virus. Further studies are needed to better understand the role of HBoV in gastrointestinal infections, particularly among patients with HIV/AIDS.

Molecular epidemiology of adenovirus conjunctivitis in Rio de Janeiro, Brazil, between 2004 and 2007.

Viral conjunctivitis is a common, highly contagious disease often caused by adenovirus. We investigate the frequency of adenoviral conjunctivitis in the population of Rio de Janeiro, Brazil, between March 2004 and May 2007 and identified the predominant serotype circulating among this population. Seventy-five ocular swabs were collected from 66 patients with clinical presentation of conjunctivitis. The specimens were analyzed for detection of adenovirus (AdV) by polymerase chain reaction (PCR). The PCR products were further analyzed for virus typing by sequence analysis and/or heteroduplex mobility assay (HMA). Forty-five samples (60%) were positive for AdV of which 21 samples were typed as AdV19 (46.7%), 7 AdV8 (15.5%), 3 AdV31 (6.7%), and one each AdV1, AdV2, AdV3, AdV4 and AdV6. For nine samples the serotype was not determined. AdV19 was the predominant serotype circulating in Rio de Janeiro during the studied period.

Molecular epidemiology of adenovirus conjunctivitis in Rio de Janeiro, Brazil, between 2004 and 2007 / Epidemiologia molecular de adenovírus associados à conjuntivite no Rio de Janeiro, Brasil, no periodo de 2004 a 2007

Viral conjunctivitis is a common, highly contagious disease often caused by adenovirus. We investigate the frequency of adenoviral conjunctivitis in the population of Rio de Janeiro, Brazil, between March 2004 and May 2007 and identified the predominant serotype circulating among this population. Seventy-five ocular swabs were collected from 66 patients with clinical presentation of conjunctivitis. The specimens were analyzed for detection of adenovirus (AdV) by polymerase chain reaction (PCR). The PCR products were further analyzed for virus typing by sequence analysis and/or heteroduplex mobility assay (HMA). Forty-five samples (60%) were positive for AdV of which 21 samples were typed as AdV19 (46.7%), 7 AdV8 (15.5%), 3 AdV31 (6.7%), and one each AdV1, AdV2, AdV3, AdV4 and AdV6. For nine samples the serotype was not determined. AdV19 was the predominant serotype circulating in Rio de Janeiro during the studied period.

A conjuntivite viral é doença ocular comum, altamente contagiosa, frequentemente causada por adenovírus. Neste estudo, investigamos a frequência de conjuntivite por adenovírus na população do Rio de Janeiro, Brasil, entre março de 2004 e maio de 2007, e identificamos o sorotipo predominante circulando nesta população. Setenta e cinco swabs de secreção ocular foram coletados de 66 pacientes com conjuntivite. As amostras foram analisadas para detecção de adenovírus (AdV) por reação em cadeia da polimerase (PCR). Os produtos da PCR foram caracterizados por sequenciamento e/ou ensaio de mobilidade do heteroduplex (Heteroduplex Mobility Assay - HMA) para identificação do sorotipo viral. Quarenta e cinco (60%) amostras foram positivas para AdV das quais 21 foram identificadas como pertencentes ao sorotipo AdV19 (46,7%), sete AdV8 (15,5%), três AdV31 (6,7%), e uma de cada: AdV1, AdV2, AdV3, AdV4 e AdV6. Para nove amostras o sorotipo não pode ser identificado. O AdV 19 foi o sorotipo predominante circulando no Rio de Janeiro durante o período estudado.

Novel respiratory virus infections in children, Brazil.

Recently discovered respiratory viruses were detected in 19 (9.2%) of 205 nasal swab specimens from children in Brazil with respiratory illnesses. Five each were positive for human metapneumovirus (HMPV) alone and human bocavirus (HBoV) alone, 3 for human coronaviruses (HCoV-HKU1 or -NL63) alone, and 6 for more than 1 recently discovered virus.

Norovirus detection and genotyping for children with gastroenteritis, Brazil.

During 1998-2005, we analyzed stool samples from 289 children in Rio de Janeiro to detect and genotype no-rovirus strains. Previous tests showed all samples to be negative for rotavirus and adenovirus. Of 42 (14.5%) no-rovirus-positive specimens, 20 (47.6%) were identified as genogroup GI and 22 (52.3%) as GII.

Human bocavirus infection in children with gastroenteritis, Brazil.

Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms.

Genotyping of enteric adenoviruses by using single-stranded conformation polymorphism analysis and heteroduplex mobility assay.

Single-stranded conformation polymorphism (SSCP) analysis and heteroduplex mobility assays (HMAs) were used to identify and genotype enteric adenoviruses (EAd). The results were compared to those of restriction endonuclease assays, species-specific PCRs, and direct nucleotide sequence analyses. Of the 31 stool samples tested, 15 isolates were identified as EAd and 7 were identified as nonenteric Ad by all methods. An agreement of 100% was found between the SSCP and HMA results.

Surveillance of rotavirus strains in Rio de Janeiro, Brazil, from 1997 to 1999.

One hundred fifty-seven (23%; n = 678) rotavirus-positive stool samples were collected between March 1997 and December 1999 in the cites of Rio de Janeiro and Niterói. Rotaviruses in 143 (91%) samples were genotyped by reverse transcription-PCR for G and/or P specificity. Rotaviruses in the majority of G-P-typeable samples (73.3%; 74 of 101) were identified as having globally common genotypes G1P[8], G2P[4], G3P[8], and G4P[8]. Unusual strains such as G1P[9], G2[P8], G3P[9], and G9P[4] strains were detected in 8.9% (9 of 101) of the samples. Genotypes G9P[8], G9P[6], and a mixture of G9 and other G or P types represented 15.9% (25 of 157) of the isolates. Mixed infections were detected in 25 (15.9%) samples, and rotaviruses in 15 samples (9.6%) were not typed.

VP7 gene polymorphism of serotype G9 rotavirus strains and its impact on G genotype determination by PCR.

Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i) G3; (ii) G4; (iii) G9; (iv) G3 and G9; or (v) G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i) a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii) the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.

VP7 gene polymorphism of serotype G9 rotavirus strains and its impact on G genotype determination by PCR.

Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i). G3; (ii). G4; (iii). G9; (iv). G3 and G9; or (v). G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i). a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii). the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.

Prevalence of enteric adenoviruses among children with diarrhea in four Brazilian cities.

BACKGROUND: Enteric adenoviruses are related to child diarrhea and appear to be spread worldwide. OBJECTIVES: The aim of the present study was to determine the prevalence of enteric adenovirus infection among children in four Brazilian cities. STUDY DESIGN: stool specimens were collected from children under 5 years of age with acute diarrhea. RESULTS AND CONCLUSIONS: Enteric adenoviruses were detected in 1.55% (n=1420) of the samples analyzed indicating the circulation of these viruses among Brazilian children in association to diarrheal disease. These agents were isolated throughout the year demonstrating no specific seasonal distribution. Also, no pattern of serotype distribution between the cities was observed.