Adenovirus respiratory infection: significant increase in diagnosis using PCR comparing with antigen detection and culture methods / Infecção respiratória aguda por adenovirus: comparação dos métodos de PCR e imunofluorescência indireta para o seu diagnóstico e dados clínicos dos pacientes infectados

Adenovirus (AdV) respiratory infections are usually described as being associated with high mortality rates. Laboratory diagnosis is essential for the establishment of the appropriate therapy, and for guiding the implementation of preventive measures in order to prevent the spread of the infection. Aiming to analyze the sensitivity and specificity of the laboratorial diagnosis methods available, we compared antigen detection by indirect immunofluorescence assay (IF), and a specific nested polymerase chain reaction (PCR), to detect AdV in respiratory samples collected from patients admitted to hospital with acute respiratory disease. Positive samples were inoculated into a cell culture to confirm the results. We analyzed 381 samples from the nasopharyngeal aspirates collected during the year 2008; of these, 2.6 percent tested were positive for adenovirus through IF and 10 percent through PCR; positive isolation was obtained in 40 percent and 26 percent of these cases, respectively. Most infected patients were children under six months of age, and despite of the fact that a significant number of patients required intensive care, the mortality rate was low (5 percent). In conclusion, molecular methods were found to be useful for rapid diagnosis of adenovirus infections with higher sensitivity than antigen detection; their introduction permitted a significant increase in diagnoses of adenovirus infections.

Infecções respiratórias por Adenovírus (ADV) são geralmente descritas associadas com alta mortalidade. O diagnóstico laboratorial é essencial para o estabelecimento da terapêutica adequada e para orientar a implantação de medidas preventivas evitando a propagação da infecção. Com o objetivo de analisar a sensibilidade e a especificidade dos métodos de avaliação de diagnóstico laboratorial, foi comparada a detecção de antígeno por imunofluorescência indireta (IF) com a reação em cadeia da polimerase específica (PCR) para detectar AdV em amostras respiratórias coletadas de pacientes internados com doença respiratória aguda. As amostras com resultados positivos foram inoculadas em cultura celular. Foram analisadas 381 amostras da secreção nasofaríngea coletadas durante o ano de 2008, das quais 2,6 por cento foram positivas pela IF e 10 por cento pela PCR, isolamento positivo foi obtido em 40 por cento e 26 por cento dos casos positivos pelos testes anteriores, respectivamente. A maioria dos pacientes infectados eram crianças com menos de seis meses de idade, e apesar do fato de que um número significativo de pacientes necessitou de cuidados intensivos, a taxa de mortalidade foi baixa (5 por cento). Em conclusão, os métodos moleculares são úteis para o diagnóstico rápido de infecções por adenovírus com maior sensibilidade do que a detecção do antígeno, a sua introdução na rotina permitiu um aumento significativo no diagnóstico de infecções por adenovírus.

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.

Diagnóstico de conjuntivite adenoviral pelo RPS Adenodetector® / Adenovirus conjunctivitis diagnosis using RPS Adenodetector®

OBJETIVO: Avaliar a utilização do RPS Adenodetector®, como método diagnóstico de pacientes com quadro clínico de conjuntivite adenoviral. MÉTODOS: Análise de série de casos consecutivos de pacientes com diagnóstico clínico de ceratoconjuntivite adenoviral submetidos comparativamente ao teste RPS Adenodetector® e a raspado conjuntival para cultura de vírus. RESULTADOS: Dos 11 pacientes avaliados, 10 pacientes apresentavam acometimento unilateral. Em relação ao tempo de início dos sintomas no momento da colheita, 5 (45,5 por cento) pacientes apresentavam dois dias de história, 5 (45,5 por cento) apresentavam três dias e 1 (9,1 por cento) apresentava 7 dias. A cultura para adenovírus foi positiva em 8 pacientes (73 por cento) e o RPS Adenodetector® foi positivo em 9 pacientes (82 por cento). Oito pacientes apresentaram o teste rápido e cultura positiva. Um paciente apresentou teste RPS Adenodetector® positivo com cultura negativa. Os dois pacientes com teste RPS Adenodetector® negativo apresentaram cultura negativa. O RPS Adenodetector® mostrou sensibilidade de 100 por cento e especificidade de 67 por cento adotando-se a cultura de vírus como exame padrão-ouro para o diagnóstico de conjuntivite adenoviral. CONCLUSÃO: O RPS Adenodetector® foi útil para o diagnóstico de conjuntivite adenoviral e pode auxiliar na orientação do paciente quanto ao contágio e disseminação da doença.

PURPOSE: To evaluate the RPS Adenodetector®, a rapid immunochromatographic test, in the diagnosis of patients with clinical overt adenoviral conjunctivitis. METHODS: Consecutive case series. Patients underwent conjunctiva scraping for RPS Adenodetector® test and culture to identify adenovirus. RESULTS: A total of 11 patients were studied, and 10 had unilateral disease. Five (45.5 percent) had symptoms for 2 days, 5 for three days, and 1 for 7 days. Adenovirus culture was positive in 8 patients (73 percent) and RPS Adenodetector® was positive in 9 (82 percent) patients. Eight patients had adenovirus identification by both methods. In one patient the RPS Adenodetector® was positive in contrast to a negative culture. The two patients revealing negative RPS Adenodetector® results also had negative cultures. The sensitivity was 100 percent and the specificity was 67 percent. CONCLUSION: The RPS Adenodetector® is a useful tool in the rapid diagnosis of adenovirus conjunctivitis and may contribute to the spread control of this highly contagious disease.

Generation and characterization of monoclonal antibodies to adenovirus.

Monoclonal antibodies (MoAbs) were generated following immunization of Balb/C mice with adenovirus type 5 grown in Hep2 cell line. Six clones reactive to hexon antigen of the virus were stabilized, of which 4 had mu-heavy chain specificity and 2 were of gamma-heavy chain type. Three of the clones (ADV-1, ADV-3 and ADV-5) had a high ELISA reactivity to the hexon antigen but exhibited differential specificity to the adenovirus types tested. In Western blotting, ADV-1 and ADV-3 reacted with all the adenovirus types tested (types 3,4,5,7 and 8) with reactions at 116 kDa region (hexon antigen), in addition, ADV-3 also had reactivity at 80 kDa region, the penton antigen. Reactivity to these adenoviral types by the 2 MoAbs was demonstrable by dot ELISA. ADV-5 had a type specific reaction only to adenovirus type 5 in dot ELISA with specificity in the hexon region in Western blotting. The reactivity of these 3 clones was not observed to the normal Hep2 tissue culture antigens and to the 3 enteroviruses tested (polio, coxsackie A9 and echo 4).

Producción de interferón-gamma e interleuquina 4 por células mononucleadas de sangre periférica infectadas con virus respiratorio sincicial y adenovirus / Interferon-gamma and interleukin-4 production by respiratory synctytial virus and adenovirus infected peripheral blood mononuclear cells

Las infecciones respiratorias por virus respiratorio sincicial (VRS) y adenovirus (Ad) son la principal causa de morbimortalidad entre las infecciones respiratorias agudas bajas (RAB) de la infancia. Ambos virus pueden dejas secuelas, al VRS se le ha atribuido desencadenar obstrucción bronquial persistente y al Ad, especialmente el Ad7h, bronquectasias, fibrosis y daño pulmonar crónico. Los mecanismos por los que estos virus pueden producir estas secuelas no se conocen, pero hay evidencias que sugieren que ésta sea causada por un mecanismo inmunológico, dependiente del tipo de virus y de la respuesta del huésped. El objetivo de este trabajo fue determinar el tipo de respuesta inmune frente a la infección por VRS y Ad mediante la cuantificación de interferón-gamma (IFN-gamma) e interleuquina-4 (IL-4), citoquinas marcadas de respuesta inmune celular y humoral respectivamente. Las ILs fueron cuantificadas en el sobrenadante de cultivo de células mononucleadas de sangre periférica infectadas o no infectadas in vitro con VRS, Ad3, Ad7h y control con mitógeno (PHA) y de células mononucleadas de lactantes con infección natural por VRS y grupo control estimuladas o no con mitógenos (PHA y PWN). Los lactantes con IRAB por VRS presentaron una disminución significativa en la producción de IFN-gamma e IL-4 por células mononucleadas no estimuladas y estimuladas con PHA. Esta disminución fue mayor para el IFN-gamma que para la IL-4, por lo que la relación IFN eta/IL-4 fue menor en estos lactantes. La producción de IL-4 pero no la de IFN-eta de los lactantes infectados con VRS que tenían antecedentes de atopia (p< 0,02). Las células mononucleadas de niños sanos infectadas in vitro con Ad estimulan la producción de IFN-gamma pero no la de IL-4 y con Ad7h, responden con una producción de IFN-gamma en este modelo in vitro. Estos resultados sugieren que la respuesta del sistema inmune frente a la infección viral dependerá del tipo de virus infectante y de la variabilidad genética del individuo. Esto demuestra la importancia de estudiar la respuesta inmune de cada virus en los diferentes individuos ya que el resultado de protección o daño dependerá de la interrelación huésped-virus

Detection of adenoviruses among Egyptian infants and young children suffering from persistent diarrhoea

Adenovirus antigen [ad. Ag] was detected in the stool of 5/36 [13.9%] of cases of persistent diarrhoea and in the stool of 1/10 [10%] of cases of acute diarrhoea. Local anti adenovirus IgA antibodies [ad. lgA] in the stool were detected in 6/36 [16.7%] of cases of persistent diarrhoea and none of cases of acute diarrhoea [p 0.01]. Elevated serum antiadenovirus 1gM antibodies [ad. 1gM] were detected in 11/36 [30.5%] and 1/10 [10] of cases of persistent and acute diarrhoea respectively. other enteric pathogens including enteropathogenic E. coli [EPEC], salmonella species, shigella, Staph aureus, Proteus, Pseudomonas, Campylobacter and Candida albicans were found in the stool of persistent and acute diarrhoea without statistical significant difference between the 2 groups except in case of candida albicans which was prevalent in the stool of patients suffering from persistent diarrhoea [P < 0.015]. Mixed infection was detected in 11.1% of cases of persistent diarrhoea only [P 0.01]. Age above one year, non breast feeding, low socioeconomic status and malnutrition appeared as risk factors for persistent diarrhoea

Rapid diagnosis of adnoviruses infections: antigens detection in nasopharyngeal secretions

Secreçöes de nasofaringe aspiradas de 479 crianças apresentando infecçäo respiratória aguda foram testadas para a presença de adenovírus pelo método clássico de isolamento em cultura de células (TCI) e dois métodos de diagnóstico rápido: imunofluorescência (IFAT) e ensaio imunoenzimático (EIA). Adenovírus foram detectados em vinte e quatro aspirados: vinte e um por TCI, dezoito por IFAT e treze por EIA. Em nove aspirados, os três métodos forneceram os mesmos resultados. Considerando somente os métodos rápidos, quinze aspirados apresentaram resultados concordantes. Os métodos rápidos apresentaram como vantagem a rapidez do diagnóstico (IFAT e EIA) e a possibilidade de se testar um grande número de amostras por dia (EIA)

Acute haemorrhagic conjunctivitis in Hong Kong 1971-1975.

Acute haemorrhagic conjunctivitis occurred in epidemic in Hong Kong in 1971 and 1975 respectively. Two picornaviruses, the Enterovirus type 70 and an antigenic variant of Coxsackie virus type A24, were isolated during the 1971 outbreak, while only the latter virus was detected in the 1975 outbreak. In 1972 and 1974, sporadic cases of conjunctivitis associated with Enterovirus type 70 were observed. Serological survey in late 1975 showed a high proportion of the population might still be susceptible to both viruses. Recrudescence of the disease is conceivable when environmental condition is favourable for the spread of these viruses.