The role of human adenoviruses type 41 in acute diarrheal disease in Minas Gerais after rotavirus vaccination

Abstract Human adenovirus species F (HAdV-F) type 40 and 41 are commonly associated with acute diarrheal disease (ADD) across the world. Despite being the largest state in southeastern Brazil and having the second largest number of inhabitants, there is no information in the State of Minas Gerais regarding the role of HAdV-F in the etiology of ADD. This study was performed to determine the prevalence, to verify the epidemiological aspects of infection, and to characterize the strains of human adenoviruses (HAdV) detected. A total of 377 diarrheal fecal samples were obtained between January 2007 and August 2011 from inpatient and outpatient children of age ranging from 0 to 12 years. All samples were previously tested for rotavirus, norovirus, and astrovirus, and 314 of 377 were negative. The viral DNA was extracted, amplified using the polymerase chain reaction and the HAdV-positive samples were sequenced and phylogenetically analyzed. Statistical analyses were performed using the Chi-square test (p < 0.05), considering two conditions: the total of samples tested (377) and the total of negative samples for the remaining viruses tested (314). The overall prevalence of HAdV was 12.47% (47/377); and in 76.60% (36/47) of the positive samples, this virus was the only infectious agent detected. The phylogenetic analysis of partial sequences of 32 positive samples revealed that they all clustered with the HAdV-F type 41. The statistical analysis showed that there was no correlation between the onset of the HAdV infection and the origin of the samples (inpatients or outpatients) in the two conditions tested: the total of samples tested (p = 0.598) and the total of negative samples for the remaining viruses tested (p = 0.614). There was a significant association in the occurrence of infection in children aged 0–12 months for the condition 1 (p = 0.030) as well as condition 2 (p = 0.019). The occurrence of infections due to HAdV did not coincide with a pattern of seasonal distribution. These data indicate the significant involvement of HAdV-F type 41 in the etiology of ADD in Minas Gerais, which demonstrates the importance of other viral agents in the development of the disease after the introduction of rotavirus vaccine immunization.

The role of human adenoviruses type 41 in acute diarrheal disease in Minas Gerais after rotavirus vaccination.

Human adenovirus species F (HAdV-F) type 40 and 41 are commonly associated with acute diarrheal disease (ADD) across the world. Despite being the largest state in southeastern Brazil and having the second largest number of inhabitants, there is no information in the State of Minas Gerais regarding the role of HAdV-F in the etiology of ADD. This study was performed to determine the prevalence, to verify the epidemiological aspects of infection, and to characterize the strains of human adenoviruses (HAdV) detected. A total of 377 diarrheal fecal samples were obtained between January 2007 and August 2011 from inpatient and outpatient children of age ranging from 0 to 12 years. All samples were previously tested for rotavirus, norovirus, and astrovirus, and 314 of 377 were negative. The viral DNA was extracted, amplified using the polymerase chain reaction and the HAdV-positive samples were sequenced and phylogenetically analyzed. Statistical analyses were performed using the Chi-square test (p<0.05), considering two conditions: the total of samples tested (377) and the total of negative samples for the remaining viruses tested (314). The overall prevalence of HAdV was 12.47% (47/377); and in 76.60% (36/47) of the positive samples, this virus was the only infectious agent detected. The phylogenetic analysis of partial sequences of 32 positive samples revealed that they all clustered with the HAdV-F type 41. The statistical analysis showed that there was no correlation between the onset of the HAdV infection and the origin of the samples (inpatients or outpatients) in the two conditions tested: the total of samples tested (p=0.598) and the total of negative samples for the remaining viruses tested (p=0.614). There was a significant association in the occurrence of infection in children aged 0-12 months for the condition 1 (p=0.030) as well as condition 2 (p=0.019). The occurrence of infections due to HAdV did not coincide with a pattern of seasonal distribution. These data indicate the significant involvement of HAdV-F type 41 in the etiology of ADD in Minas Gerais, which demonstrates the importance of other viral agents in the development of the disease after the introduction of rotavirus vaccine immunization.

Study of the dynamic of rotavirus circulation by identification of their electropherotypes / Estudo da dinâmica de circulação de rotavírus através da identificação de seus eletroferótipos eletroferótipos

An electrophoretical study of rotavirus strains was carried out to determine the RNA migration pattern sand to follow the dynamics of virus circulation. Fifty five positive fecal samples for rotavirus, obtained from 0-5 year old children during 2005 and 2006, were subjected to the Polyacrylamide Gel Electrophoresis. It was possible to define the RNA migration pattern of 37 (62%) rotavirus strains, displaying eight distinct profiles, all of them compatible with group A rotavirus. All rotavirus were detected from May to September showing an outstanding seasonality. In 2005 were detected only rotavirus strains presenting long migration patterns (100%=15/15), named L1, L2, L3 or L4. The L2 profile was predominant. However, in 2006, a few rotavirus strains displaying long migration patterns (L1 and L2) were detected (14%=3/22) from May to June, although rotavirus strains presenting short migration patterns (S1, S2, S3 or S4) were detected between Julyand August. These viruses of short RNA migration patterns were the most predominant strains (86%=19/22). The variability of RNA migration patterns detected showed a great genomic heterogeneity of rotavirus strains. By monitoring viral nucleic acid electrophoretic characteristics was possible to follow the dynamics of rotavirus circulation between 2005 and 2006.

Foi realizado um estudo eletroforético de amostras de rotavírus, visando determinar os perfis de migração do RNA viral, bem como acompanhar a dinâmica da circulação dos mesmos. Para tanto, 55 amostras fecais diarréicas, positivas para rotavírus, obtidas de crianças de 0-5 anos, durante os anos de 2005 e 2006, foram submetidas à técnica de eletroforese em gel de poliacrilamida. Foi possível definir o perfil eletroforético de 37 (62%) delas, tendo sido observados oito perfis distintos, todos compatíveis com rotavírus do grupo A. Todas as amostras de rotavírus foram detectadas de maio a setembro, indicando uma sazonalidade na ocorrência destas infecções em Juiz de Fora. Em 2005 todas as amostras apresentaram perfis longos (100%=15/15), denominados de L1 a L4, com predominância de amostras de perfil L2. Em 2006, poucas amostras de perfil longo (14%=3/22) foram detectadas nos meses de maio e junho, tendo sido substituídas pelas amostras de perfil curto (C1-C4), que emergiram em julho, predominando neste ano (86%=19/22). A variabilidade dos perfis eletroforéticos detectados mostrou uma grande heterogeneidade genômica e através do monitoramento foi possível acompanhar a dinâmica de circulação das amostras de rotavírus entre 2005 e 2006.