Molecular epidemiology of adenoviruses associated with acute lower respiratory disease of children in Buenos Aires, Argentina (1984-1988).

DNA restriction analysis was carried out on a sample of 73 adenovirus strains isolated in Buenos Aires from nasopharyngeal aspirates of children with lower acute respiratory infection between 1984 and 1988. Thirty-five isolates (47.9%) were classified as members of subgenus B. Of these, three were identified as a new genome type of Ad3p denominated Ad3p3; five strains corresponded to genome type 7b and two to genome type 7c. The other 25 isolates were identified as the recently recognized genome type 7h. All 6 fatalities recorded within this group of 73 children were associated with infection by Adenovirus genome type 7h. Thirty-seven isolates (50.7%) were classified within subgenus C that corresponded to 9 different genome types denominated 1p (n = 5); 1# (n = 2); 2p (n = 4); 2b (n = 6); 2# (n = 5); 5# (n = 4); 5* (n = 7) and 5+ (n = 2). All genome types of subgenus C were compared with the data reported by Adrian et al. (Archives of Virology 112:235-238, 1990). The Ad1p and Ad1# genome types could be allocated to AV1 genome types D1 and D10, respectively. Ad2b genome type could be allocated to AV2 genome type D25. No counterparts were found for the remaining 6 genomic variants. Only one isolate was identified as Ad4a of subgenus E. The comparison of the results of the present study with those of the molecular characterization of Chilean strains isolated between 1984 and 1987 suggests that the adenovirus strains associated with respiratory disease of children may be common in both countries.     

Molecular characterization of human adenoviruses associated with respiratory infection in Turkey

Human adenoviruses (HAdVs) are responsible for various clinical diseases. Molecular epidemiological studies of respiratory HAdVs are limited in Turkey. To determine the main genotypes and epidemiological characteristics of HAdVs in patients with respiratory symptoms. HAdV PCR‐positive extracts of nasal/nasopharyngeal specimens sent to the Turkish Public Health Institution from various cities of Turkey in 2015–2016 were investigated by seminested PCR. Partial sequence analysis of the hexon gene of HAdVs was performed. SPSSv.24.0 was used. A total of 23/68 (33.82%) HAdV‐positive samples were amplified. Mastadenovirus B, C, D, and F were detected and mastadenovirus B (10/23; 43.5%) and C (10/23; 43.5%) were predominant strains. Interestingly, HAdV‐F known to have gastrointestinal system tropism was detected in two patients with respiratory symptoms. HAdV‐B3 was the most prevalent genotype (9/23; 39.1%). Also, HAdV‐B7 is defined as a reemerging pathogen. It is noteworthy that there is a cluster of four HAdV‐C strains showing a close paraphyletic relationship with HAdV‐2/6 intertypic recombination. To our knowledge, this is the first study showing that HAdV‐B7 reemerging pathogen circulating in patients with respiratory infections in our country. It is also necessary to emphasize that HAdV‐2/6 recombinant strains were detected in this study for the first time in Turkey.     

Prevalence of human respiratory viruses in adults with acute respiratory tract infections in Beijing, 2005–2007

To determine the aetiological role and epidemiological profile of common respiratory viruses in adults with acute respiratory tract infections (ARTIs), a 2-year study was conducted in Beijing, China, from May 2005 to July 2007. Nose and throat swab samples from 5808 ARTI patients were analysed by PCR methods for common respiratory viruses, including influenza viruses (IFVs) A, B, and C, parainfluenza viruses (PIVs) 1–4, enteroviruses (EVs), human rhinoviruses (HRVs), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), human coronaviruses (HCoVs) OC43, 229E, NL63, and HKU1, and adenoviruses (ADVs). Viral pathogens were detected in 34.6% of patient samples, and 1.6% of the patients tested positive for more than one virus. IFVs (19.3%) were the dominant agents detected, followed by HRVs (6.5%), PIVs (4.3%), EVs (3.2%), and HCoVs (1.1%). ADVs, RSV and HMPV were also detected (<1%). The viral detection rates differed significantly between infections of the lower and upper respiratory tracts in the sample population: PIVs, the second most commonly detected viral agents in lower acute respiratory tract infections (LRTIs), were more prevalent than in upper acute respiratory tract infections, indicating that the pathogenic role of PIVs in LRTIs should be investigated. Currently, this study is the largest-scale investigation of respiratory virus infections in China with multiple agent detection, providing baseline data for further studies of respiratory virus infections in adults with ARTIs.     

北京地区婴幼儿急性呼吸道感染与新近报道的人细小病毒相关性的初步研究

目的了解北京地区婴幼儿急性呼吸道感染与新近报道的人细小病毒（human bocavirus,HBoV）的关系.方法选择2003年11月至2004年2月收集的经间接免疫荧光和/或病毒分离排除了常见呼吸道病毒感染的急性呼吸道感染患儿标本319例,应用针对HBoV的NP1基因的PCR引物进行HBoV基因片段检测,随机选取HBoV基因检测阳性标本中的5例,对其PCR扩增产物直接进行核苷酸序列测定.将所测到的序列与GenBank中的基因序列进行比较分析.结果319例标本中HBoV基因检测阳性的为13例,其阳性检出率占本组检测标本的4.1%;HBoV阳性检出率在本组的毛细支气管炎患儿中最高,达10.9%（5/46）,其次为支气管炎患儿（6.3%,2/32）;HBoV检测阳性标本的患儿年龄主要分布于5个月～5岁,尤其是＜1岁的患儿;其中6～7个月的患儿中HBoV检测阳性的占50%（2/4）,9～10个月的患儿中阳性的占25%（2/8）,其次为5～6个月的患儿（18.2%）、11个月～1岁的患儿（14.3%）及8～9个月的患儿（12.5%）;在＜5个月的总计103例患儿中以及＞5岁的28例患儿中均未检测到HBoV阳性标本;基因序列分析表明,本研究中5例北京的HBoV之间基因序列的同源性在99.7%～100%之间;与st1、st2株的同源性为99.2%～99.4%.结论本研究结果提示北京地区部分儿科患者的急性呼吸道感染与HBoV有关,且HBoV感染在低年龄组儿童中更为常见.     

重庆地区急性呼吸道感染患儿呼吸道合胞病毒流行特征及其G基因序列分析

目的 分析重庆地区2008-2009年度急性呼吸道感染住院患儿呼吸道合胞病毒(respiratory syncytial virus,RSV)的亚型流行情况,并了解优势流行株BA株的G蛋白基因特征.方法 采集2008年4月-2009年3月全年于重庆医科大学附属儿童医院因急性呼吸道感染住院的508例患儿鼻咽深部分泌物,用RT-PCR方法检测RSV并进行亚型鉴定,选取29例B亚型和10例A亚型RSV阳性标本,用RT-PCR的方法扩增全长G蛋白并测序.结果 在508例标本中,RSV阳性126例(24.8%),其中检测出A亚型43例(34.1%),B亚型80例(63.5%),A、B亚型混合感染3例(2.4%).所测的10株A亚型的G基因与标准株A2的核苷酸同源性为91.4%～92.0%,均属GA2基因型;29株B亚型的G基因与标准株CH18537的核苷酸同源性为92.0%～93.0%,其中19株均为具有60个高度重复核苷酸插入的BA株.B亚型流行株与CH18537标准株相比,G基因有多种核苷酸变异如缺失、插入等,尤其在G蛋白近C端1/3处的高变区.结论 2008-2009年RSV仍是重庆地区儿童急性呼吸道感染的主要病原,与既往两年A亚型优势流行不同,2008-2009年度B亚型毒株流行占优;近年新发现的BA株可能已成为本地区优势流行株,BA株G基因变异是否导致G蛋白功能增强,进而促进其优势流行尚有待研究.     

Ethnobotanical and antimicrobial studies of some plants used in Kibwezi (Kenya) for management of lower respiratory tract infections

Respiratory tract infections have gained worldwide recognition especially due to the increased incidence of HIV/AIDS. The bacteria responsible for these infections have also become increasingly resistant to chemotherapeutic agents in lower respiratory infections in Kibwezi in Kenya. Interviews were conducted using semi-structured questionnaires and detailed discussions with respondents. During the field surveys direct observations were made on how these plants are used. From the ethnobotanical survey the modes of preparation used included chewing and boiling. The plant parts used were mostly bark and root, which implies that the main methods of harvesting these plants are destructive in nature. Water and methanolic extracts of the three most popular plants, Acacia nilotica, Strychnos heninngsii and Microglossa densiflora were tested against three test organism: Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli for their antimicrobial properties. The efficacy of the extracts was tested by bioassay method using the disk diffusion test. It was interesting to note that none of the tested water extracts showed any activity against the test organisms. This is despite the fact that about 83% of the local people used water for extraction. Methanolic extracts of Acacia nilotica and Strychnos heninningsii showed efficacy against S. aureus, S. pneumoniae and E. coli. The findings of this research indicate that A. nilotica and S. heninngsii have antimicrobial properties and further work especially using mammalian models is recommended.     

Multicentered study of viral acute lower respiratory infections in children from four cities of Argentina, 1993-1994

This study describes the first multicentered study of acute lower respiratory infection viral etiology in young children from four different geographical areas of Argentina. A total of 1,278 children under 5 years of age, hospitalized in primary care centers from Buenos Aires, Córdoba, Santa Fé and Mar del Plata cities during a 2-year period were studied (1993-1994). Nasopharyngeal aspirates were investigated for respiratory syncytial virus (RSV), adenovirus, parainfluenza, and influenza A and B viruses by indirect immunofluorescence. Out of the patients studied, 946 (74%) were under 1 year of age. Viruses were detected in 399 patients (32%). RSV was observed in 25.3% of the samples, representing 78.2% of all viral positive cases. Adenoviruses were detected in 2.5% of the cases, parainfluenza in 2.2%, influenza A in 2.1%, and influenza B in 0.2%. Compared with other viruses, the higher RSV frequency was statistically significant (P < 0.000). Most RSV cases were detected between May and September with a significant peak in July (P < 0.000). Pneumonia was observed in 46% of the patients, bronchiolitis in 41% and other entities in 13%. The case fatality rate observed during the 2 year study was 0.73%. Most of the above respiratory viruses were detected in the four cities, however, the frequency of RSV and influenza were different in the southern city.     

Molecular epidemiology of human respiratory syncytial virus subgroup A over a six-year period (1999-2004) in Argentina

Human respiratory syncytial virus (HRSV) is the main viral cause of acute lower respiratory tract infections in children. Little information about the molecular epidemiology of HRSV in developing countries, such as Argentina, is available. By RT-PCR, we subgrouped 353 HRSV isolates over six consecutive epidemic seasons (1999-2004) and few isolates from 1997. Between them, 232 (65.7%) belonged to subgroup A and 121 (34.3%) to subgroup B. Therefore, the nucleotide, amino-acid variability and phylogenetic relations of 78 HRSV subgroup A isolates, were analyzed using RFLP and sequence analysis of the G-protein gene. The results showed that there were two main restriction patterns (PA1 and PA2) and two previously described genotypes (GA2 and GA5) cocirculating in Buenos Aires, without evidence of alternation between them during the studied period. The Argentine sequences were compared with previously reported molecular data from other countries. It showed that viruses genetically related circulated the same years within neighboring countries and the sequences from long-distant places were closely related to Argentine sequences, but they belonged to different sampling years. The data reported here support the growing database on the molecular diversity of HRSVA circulating in Latin America in children under 2 years of age and contributes to describe the pattern of global spread of this virus.