- Email: [email protected]
Endobronchial ultrasound-guided biopsy in the evaluation of intrathoracic lymphadenopathy in suspected tuberculosis: A minimally invasive technique with a high diagnostic yield
Letters to the Editor
309 Chun-Hsing Liao Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei County, Taiwan Chih-Cheng Lai Department of Internal Medicine, Yi-Min Hospital, Taipei, Taiwan Yu-Tsung Huang Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Chien-Hong Chou Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan Hsiao-Leng Hsu Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
Figure 1 Magnetic resonance image (MRI) of the left ankle shows soft tissue swelling and abscess formation (arrow) between the peroneus and Achilles tendon caused by M. conceptionese.
implicated species is imperative to evaluate its role in human infection and apply the appropriate treatment. Study of more clinical isolates is needed to decipher the spectrum of the clinical disease caused by M. conceptionese.
References 1. Yang SC, Hsueh PR, Lai HC, Teng LJ, Huang LM, Chen JM, et al. High prevalence of antimicrobial resistance among rapidly growing mycobacteria in Taiwan. Antimicrob Agents Chemother 2003;47:1958e62. 2. Ade ´kambi T, Drancourt M. Dissection of phylogenic relationships among nineteen rapidly growing mycobacterium species by 16S rRNA, hsp65, sodA, recA, and rpoB gene sequencing. Int J Syst Evol Microbiol 2004;54:2095e105. 3. Ade ´kambi T, Stein A, Carvajal J, Raoult D, Drancourt M. Description of Mycobacterium conceptionense sp. nov., a Mycobacterium fortuitum group organism isolated from a posttraumatic osteitis inflammation. J Clin Microbiol 2006;44:1268e73. 4. Liao CH, Lai CC, Ding LW, Hou SM, Chiu HC, Chang SC, et al. Skin and soft tissue infection caused by non-tuberculous mycobacteria. Int J Tuberc Lung Dis 2007;11:96e102. 5. Ade ´kambi T, Berger P, Raoult D, Drancourt M. rpoB gene sequence-based characterization of emerging non-tuberculous mycobacteria with descriptions of Mycobacterium bolletii sp. nov., Mycobacterium phocaicum sp. nov. and Mycobacterium aubagnense sp. nov. Int J Syst Evol Microbiol 2006;56:133e43. 6. Schinsky MF, Morey RE, Steigerwalt AG, Douglas MP, Wilson RW, Floyd MM, et al. Taxonomic variation in the Mycobacterium fortuitum third biovariant complex: description of Mycobacterium boenickei sp. nov., Mycobacterium houstonense sp. nov., Mycobacterium neworleansense sp. nov. and Mycobacterium brisbanense sp. nov. and recognition of Mycobacterium porcinum from human clinical isolates. Int J Syst Evol Microbiol 2004;54:1653e67.
Po-Ren Hsueh* Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan *Corresponding author at: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University College of Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 100, Taiwan. Tel.: þ886 2 23123456x65355. E-mail address: [email protected] 24 February 2009 Available online 16 March 2009 ª 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jinf.2009.02.012
Endobronchial ultrasound-guided biopsy in the evaluation of intrathoracic lymphadenopathy in suspected tuberculosis: A minimally invasive technique with a high diagnostic yield Mediastinal intrathoracic lymphadenopathy is a common manifestation of infection with Mycobacterium tuberculosis in HIV-infected patients and less commonly in HIVuninfected patients.1 However, infection with HIV also predisposes patients to many conditions that may result in intrathoracic lymphadenopathy presenting the clinician with a diagnostic challenge.2 Establishing a definitive diagnosis by tissue biopsy in this setting is important and previously necessitated invasive surgical procedures. Endobronchial ultrasound-guided transbronchial needle
310 aspiration (EBUS-TBNA) is a relatively novel technique developed to allow mediastinal staging of lung cancer by minimally invasive means. Diagnostic yield and complication rate of EBUS-TBNA compare favourably to invasive mediastinoscopy in this setting.3,4 Efficacy in evaluation of other disease processes such as sarcoidosis and lymphoma has also been established.5 There are currently no data on the use of this technique in HIV-infected patients. We highlight the utility and high diagnostic yield of EBUS-TBNA for the investigation of mediastinal intrathoracic lymphadenopathy in two HIV-infected patients.
Case 1 A 45 year-old HIV-infected male was referred to our service with mediastinal intrathoracic lymphadenopathy on chest radiograph. He gave no history of overseas travel, reported no respiratory symptoms and was constitutionally well. He had started anti-retroviral treatment three months prior and his absolute CD4 count was 4 106/L. CT chest revealed right-sided upper and lower paratracheal lymphadenopathy. Routine bronchoscopy was unremarkable and bronchoalveolar lavage washings were culture negative. EBUS-TBNA was performed under conscious sedation using a dedicated linear array bronchoscope (BF-UC160F-OL8, Olympus, Tokyo, Japan). Histopathology of the biopsy specimens showed necrotizing granulomatous inflammation and ZiehleNeelsen staining revealed acid-fast bacilli (AFBs). Mycobacterium Avium Complex (MAC) was detected by PCR from the tissue biopsy specimen and subsequently grown on tissue culture. Appropriate treatment was started and on follow up the patient remains well.
Case 2 A 15 year-old girl was referred to our institution with mediastinal intrathoracic lymphadenopathy on chest radiograph. Health screening by her local practitioner identified
Letters to the Editor her as HIV positive. Her absolute CD4 count was 598 106/ L. A tuberculin skin test showed greater than 30 mm induration after 48 h with associated central ulceration. Chest CT revealed right-sided paratracheal lymphadenopathy (Fig. 1a). EBUS-TBNA sampling was performed under general anaesthesia with a laryngeal mask airway (Fig. 1b). Histopathology examination showed necrotizing granulomatous inflammation and, although ZiehleNeelsen staining was negative for AFBs, Mycobacterium tuberculosis DNA was detected by PCR from the biopsy specimen and subsequently grown in tissue culture. Susceptibility testing of the isolate revealed resistance to Rifampicin and Streptomycin. Based on these results, maintenance phase treatment was changed to Isoniazid and Ethambutol. On follow up the patient remains well. Our cases highlight the potential utility of EBUS-TBNA in establishing an accurate and timely tissue diagnosis in HIVinfected patients with mediastinal intrathoracic lymphadenopathy. The presence of mediastinal intrathoracic lymphadenopathy on chest radiograph can lead to diagnostic confusion. This is particularly true in HIV-infected patients, in whom, mediastinal intrathoracic lymphadenopathy is commonly seen accompanying other conditions including lymphoma, Kaposi’s sarcoma, Castleman’s disease, and infections such as Histoplasmosis, Mycobacterium tuberculosis (TB) or Mycobacterium Avium complex (MAC).2 The ability to obtain an adequate tissue diagnosis for drug susceptibility testing, as illustrated in the second case, is particularly important in an era when Multi-Drug Resistant TB is of increasing concern and Extensively Drug resistant TB represents an additional new threat. In most similar situations, a tissue diagnosis would have remained elusive in this setting necessitating empiric anti-tuberculous treatment. Conventional TBNA of mediastinal lymph nodes has proven useful for the diagnosis of TB in HIV-infected patients, but the potential for serious complications such as inadvertent vascular puncture has limited its widespread use.6 In contrast EBUS-TBNA is an extremely safe
Figure 1 (a) CT chest demonstrating right paratracheal lymphadenopathy (LN); (b) EBUS image showing hyper-echoic lymph node margin (arrows) and biopsy needle within the lymph node (arrowheads). Doppler mode window demonstrates vascular flow within an internodal artery (A).
Letters to the Editor procedure, with no significant complications reported in the literature to date. The quality of the clinical sample obtained using EBUS-TBNA is higher than that for conventional TBNA and, unlike conventional TBNA, EBUS-TBNA has been shown to be useful for the diagnosis of sarcoidosis and lymphoma,5 both of which are seen with increased frequency in HIV-infected patients. EBUS-TBNA has several advantages over traditional methods of tissue biopsy: diagnostic yield is frequently superior to mediastinoscopy3; it has an excellent safety profile7; use of the technique is not limited to adult populations8; and it can be performed as a day case, thereby reducing hospital costs. To our knowledge this is the first report to demonstrate the feasibility and high diagnostic yield of EBUS-TBNA for the investigation of mediastinal intrathoracic lymphadenopathy in HIV-infected patients. EBUS-TBNA, where available, should be considered for the investigation of mediastinal intrathoracic lymphadenopathy in patients that do not have lesions more amenable to diagnostic sampling.
311 Douglas F. Johnson Department of Infectious Diseases, Austin Hospital, Victoria 3084, Australia Tom G. Connell Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia Murdoch Children’s Research Institute, Parkville, Victoria 3052, Australia Infectious Diseases Unit, Royal Children’s Hospital Melbourne, Parkville, Victoria 3052, Australia Louis B. Irving Department of Respiratory Medicine, Royal Melbourne Hospital, Victoria 3050, Australia 10 February 2009
Conflict of interest None declared.
References 1. Leung AN, Brauner MW, Gamsu G, Mlika-Cabanne N, Ben Romdhane H, Carette MF, et al. Pulmonary tuberculosis: comparison of CT findings in HIV-seropositive and HIV-seronegative patients. Radiology 1996;198:687e91. 2. Boyton RJ. Infectious lung complications in patients with HIV/AIDS. Curr Opin Pulm Med 2005;11:203e7. 3. Ernst A, Anantham D, Eberhardt R, Krasnik M, Herth FJ. Diagnosis of mediastinal adenopathy-real-time endobronchial ultrasound guided needle aspiration versus mediastinoscopy. J Thorac Oncol 2008;3:577e82. 4. Rodriguez P, Santana N, Gamez P, Rodrı´guez de Castro F, Varela de Ugarte A, Freixinet J. Mediastinoscopy in the diagnosis of mediastinal disease. An analysis of 181 explorations. Arch Bronconeumol 2003;39:29e34. 5. Kennedy MP, Jimenez CA, Bruzzi JF, Mhatre AD, Lei X, Giles FJ, et al. Endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of lymphoma. Thorax 2008;63:360e5. 6. Haponik EF, Shure D. Underutilization of transbronchial needle aspiration: experiences of current pulmonary fellows. Chest 1997;112:251e3. 7. Yasufuku K, Nakajima T, Fujiwara T, Chiyo M, Iyoda A, Yoshida S, et al. Role of endobronchial ultrasound-guided transbronchial needle aspiration in the management of lung cancer. Gen Thorac Cardiovasc Surg 2008;56:268e76. 8. Steinfort DP, Wurzel D, Irving LB, Ranganathan SC. Endobronchial ultrasound in pediatric pulmonology. Pediatr Pulmonol, in press.
Daniel P. Steinfort* Department of Respiratory Medicine, Royal Melbourne Hospital, Grattan St, Parkville, Victoria 3050, Australia *Corresponding author. Tel.: þ61 3 9342 7708; fax: þ61 3 9342 8493. E-mail address: [email protected]
Available online 14 March 2009 Crown Copyright ª 2009 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jinf.2009.02.003
Phylogenetic analysis of human bocavirus (HBoV) detected from children with acute respiratory infection in Japan
Dear Editor Human bocavirus (HBoV) belongs to family Parvoviridae and causes acute respiratory infection (ARI) in humans.1 HBoV is an emerging virus discovered by Allander et al. in 2005 from a Swedish patient with ARI.2 Although the clinical course of HBoV infection in most patients is good, it is suggested that HBoV is associated with lower respiratory infection including bronchiolitis and pneumoniae3e5; however, its epidemiology remains poorly understood at present.3 In this study, in an attempt to clarify the epidemiology, we performed phylogenetic analysis of HBoV detected from Japanese children with ARI in recent years. We obtained 7 amplicons of HBoV from patients (age range, 6 monthse2 years) with ARI. Their inhabitant areas were Yamagata prefecture (3 patients), Shiga prefecture (2 patients), Fukushima prefecture (1 patient), and Tokyo metropolitan (1 patient). We initially extracted DNA from throat swabs and amplified the full-length HBoV genome as previously described.6 The obtained amplicons were then sequenced and aligned.6 We next performed phylogenetic analysis, after which evolutionary distances were estimated using Kimura’s two-parameter method and phylogenic trees were constructed using the neighbor-joining (N-J) method.6 As shown in Fig. 1, 6 strains (3 from upper respiratory infection, 1 from bronchiolitis, and 2 from pneumonia)
309 Chun-Hsing Liao Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei County, Taiwan Chih-Cheng Lai Department of Internal Medicine, Yi-Min Hospital, Taipei, Taiwan Yu-Tsung Huang Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Chien-Hong Chou Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan Hsiao-Leng Hsu Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
Figure 1 Magnetic resonance image (MRI) of the left ankle shows soft tissue swelling and abscess formation (arrow) between the peroneus and Achilles tendon caused by M. conceptionese.
implicated species is imperative to evaluate its role in human infection and apply the appropriate treatment. Study of more clinical isolates is needed to decipher the spectrum of the clinical disease caused by M. conceptionese.
References 1. Yang SC, Hsueh PR, Lai HC, Teng LJ, Huang LM, Chen JM, et al. High prevalence of antimicrobial resistance among rapidly growing mycobacteria in Taiwan. Antimicrob Agents Chemother 2003;47:1958e62. 2. Ade ´kambi T, Drancourt M. Dissection of phylogenic relationships among nineteen rapidly growing mycobacterium species by 16S rRNA, hsp65, sodA, recA, and rpoB gene sequencing. Int J Syst Evol Microbiol 2004;54:2095e105. 3. Ade ´kambi T, Stein A, Carvajal J, Raoult D, Drancourt M. Description of Mycobacterium conceptionense sp. nov., a Mycobacterium fortuitum group organism isolated from a posttraumatic osteitis inflammation. J Clin Microbiol 2006;44:1268e73. 4. Liao CH, Lai CC, Ding LW, Hou SM, Chiu HC, Chang SC, et al. Skin and soft tissue infection caused by non-tuberculous mycobacteria. Int J Tuberc Lung Dis 2007;11:96e102. 5. Ade ´kambi T, Berger P, Raoult D, Drancourt M. rpoB gene sequence-based characterization of emerging non-tuberculous mycobacteria with descriptions of Mycobacterium bolletii sp. nov., Mycobacterium phocaicum sp. nov. and Mycobacterium aubagnense sp. nov. Int J Syst Evol Microbiol 2006;56:133e43. 6. Schinsky MF, Morey RE, Steigerwalt AG, Douglas MP, Wilson RW, Floyd MM, et al. Taxonomic variation in the Mycobacterium fortuitum third biovariant complex: description of Mycobacterium boenickei sp. nov., Mycobacterium houstonense sp. nov., Mycobacterium neworleansense sp. nov. and Mycobacterium brisbanense sp. nov. and recognition of Mycobacterium porcinum from human clinical isolates. Int J Syst Evol Microbiol 2004;54:1653e67.
Po-Ren Hsueh* Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan *Corresponding author at: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University College of Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 100, Taiwan. Tel.: þ886 2 23123456x65355. E-mail address: [email protected] 24 February 2009 Available online 16 March 2009 ª 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jinf.2009.02.012
Endobronchial ultrasound-guided biopsy in the evaluation of intrathoracic lymphadenopathy in suspected tuberculosis: A minimally invasive technique with a high diagnostic yield Mediastinal intrathoracic lymphadenopathy is a common manifestation of infection with Mycobacterium tuberculosis in HIV-infected patients and less commonly in HIVuninfected patients.1 However, infection with HIV also predisposes patients to many conditions that may result in intrathoracic lymphadenopathy presenting the clinician with a diagnostic challenge.2 Establishing a definitive diagnosis by tissue biopsy in this setting is important and previously necessitated invasive surgical procedures. Endobronchial ultrasound-guided transbronchial needle
310 aspiration (EBUS-TBNA) is a relatively novel technique developed to allow mediastinal staging of lung cancer by minimally invasive means. Diagnostic yield and complication rate of EBUS-TBNA compare favourably to invasive mediastinoscopy in this setting.3,4 Efficacy in evaluation of other disease processes such as sarcoidosis and lymphoma has also been established.5 There are currently no data on the use of this technique in HIV-infected patients. We highlight the utility and high diagnostic yield of EBUS-TBNA for the investigation of mediastinal intrathoracic lymphadenopathy in two HIV-infected patients.
Case 1 A 45 year-old HIV-infected male was referred to our service with mediastinal intrathoracic lymphadenopathy on chest radiograph. He gave no history of overseas travel, reported no respiratory symptoms and was constitutionally well. He had started anti-retroviral treatment three months prior and his absolute CD4 count was 4 106/L. CT chest revealed right-sided upper and lower paratracheal lymphadenopathy. Routine bronchoscopy was unremarkable and bronchoalveolar lavage washings were culture negative. EBUS-TBNA was performed under conscious sedation using a dedicated linear array bronchoscope (BF-UC160F-OL8, Olympus, Tokyo, Japan). Histopathology of the biopsy specimens showed necrotizing granulomatous inflammation and ZiehleNeelsen staining revealed acid-fast bacilli (AFBs). Mycobacterium Avium Complex (MAC) was detected by PCR from the tissue biopsy specimen and subsequently grown on tissue culture. Appropriate treatment was started and on follow up the patient remains well.
Case 2 A 15 year-old girl was referred to our institution with mediastinal intrathoracic lymphadenopathy on chest radiograph. Health screening by her local practitioner identified
Letters to the Editor her as HIV positive. Her absolute CD4 count was 598 106/ L. A tuberculin skin test showed greater than 30 mm induration after 48 h with associated central ulceration. Chest CT revealed right-sided paratracheal lymphadenopathy (Fig. 1a). EBUS-TBNA sampling was performed under general anaesthesia with a laryngeal mask airway (Fig. 1b). Histopathology examination showed necrotizing granulomatous inflammation and, although ZiehleNeelsen staining was negative for AFBs, Mycobacterium tuberculosis DNA was detected by PCR from the biopsy specimen and subsequently grown in tissue culture. Susceptibility testing of the isolate revealed resistance to Rifampicin and Streptomycin. Based on these results, maintenance phase treatment was changed to Isoniazid and Ethambutol. On follow up the patient remains well. Our cases highlight the potential utility of EBUS-TBNA in establishing an accurate and timely tissue diagnosis in HIVinfected patients with mediastinal intrathoracic lymphadenopathy. The presence of mediastinal intrathoracic lymphadenopathy on chest radiograph can lead to diagnostic confusion. This is particularly true in HIV-infected patients, in whom, mediastinal intrathoracic lymphadenopathy is commonly seen accompanying other conditions including lymphoma, Kaposi’s sarcoma, Castleman’s disease, and infections such as Histoplasmosis, Mycobacterium tuberculosis (TB) or Mycobacterium Avium complex (MAC).2 The ability to obtain an adequate tissue diagnosis for drug susceptibility testing, as illustrated in the second case, is particularly important in an era when Multi-Drug Resistant TB is of increasing concern and Extensively Drug resistant TB represents an additional new threat. In most similar situations, a tissue diagnosis would have remained elusive in this setting necessitating empiric anti-tuberculous treatment. Conventional TBNA of mediastinal lymph nodes has proven useful for the diagnosis of TB in HIV-infected patients, but the potential for serious complications such as inadvertent vascular puncture has limited its widespread use.6 In contrast EBUS-TBNA is an extremely safe
Figure 1 (a) CT chest demonstrating right paratracheal lymphadenopathy (LN); (b) EBUS image showing hyper-echoic lymph node margin (arrows) and biopsy needle within the lymph node (arrowheads). Doppler mode window demonstrates vascular flow within an internodal artery (A).
Letters to the Editor procedure, with no significant complications reported in the literature to date. The quality of the clinical sample obtained using EBUS-TBNA is higher than that for conventional TBNA and, unlike conventional TBNA, EBUS-TBNA has been shown to be useful for the diagnosis of sarcoidosis and lymphoma,5 both of which are seen with increased frequency in HIV-infected patients. EBUS-TBNA has several advantages over traditional methods of tissue biopsy: diagnostic yield is frequently superior to mediastinoscopy3; it has an excellent safety profile7; use of the technique is not limited to adult populations8; and it can be performed as a day case, thereby reducing hospital costs. To our knowledge this is the first report to demonstrate the feasibility and high diagnostic yield of EBUS-TBNA for the investigation of mediastinal intrathoracic lymphadenopathy in HIV-infected patients. EBUS-TBNA, where available, should be considered for the investigation of mediastinal intrathoracic lymphadenopathy in patients that do not have lesions more amenable to diagnostic sampling.
311 Douglas F. Johnson Department of Infectious Diseases, Austin Hospital, Victoria 3084, Australia Tom G. Connell Department of Paediatrics, University of Melbourne, Parkville, Victoria 3052, Australia Murdoch Children’s Research Institute, Parkville, Victoria 3052, Australia Infectious Diseases Unit, Royal Children’s Hospital Melbourne, Parkville, Victoria 3052, Australia Louis B. Irving Department of Respiratory Medicine, Royal Melbourne Hospital, Victoria 3050, Australia 10 February 2009
Conflict of interest None declared.
References 1. Leung AN, Brauner MW, Gamsu G, Mlika-Cabanne N, Ben Romdhane H, Carette MF, et al. Pulmonary tuberculosis: comparison of CT findings in HIV-seropositive and HIV-seronegative patients. Radiology 1996;198:687e91. 2. Boyton RJ. Infectious lung complications in patients with HIV/AIDS. Curr Opin Pulm Med 2005;11:203e7. 3. Ernst A, Anantham D, Eberhardt R, Krasnik M, Herth FJ. Diagnosis of mediastinal adenopathy-real-time endobronchial ultrasound guided needle aspiration versus mediastinoscopy. J Thorac Oncol 2008;3:577e82. 4. Rodriguez P, Santana N, Gamez P, Rodrı´guez de Castro F, Varela de Ugarte A, Freixinet J. Mediastinoscopy in the diagnosis of mediastinal disease. An analysis of 181 explorations. Arch Bronconeumol 2003;39:29e34. 5. Kennedy MP, Jimenez CA, Bruzzi JF, Mhatre AD, Lei X, Giles FJ, et al. Endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of lymphoma. Thorax 2008;63:360e5. 6. Haponik EF, Shure D. Underutilization of transbronchial needle aspiration: experiences of current pulmonary fellows. Chest 1997;112:251e3. 7. Yasufuku K, Nakajima T, Fujiwara T, Chiyo M, Iyoda A, Yoshida S, et al. Role of endobronchial ultrasound-guided transbronchial needle aspiration in the management of lung cancer. Gen Thorac Cardiovasc Surg 2008;56:268e76. 8. Steinfort DP, Wurzel D, Irving LB, Ranganathan SC. Endobronchial ultrasound in pediatric pulmonology. Pediatr Pulmonol, in press.
Daniel P. Steinfort* Department of Respiratory Medicine, Royal Melbourne Hospital, Grattan St, Parkville, Victoria 3050, Australia *Corresponding author. Tel.: þ61 3 9342 7708; fax: þ61 3 9342 8493. E-mail address: [email protected]
Available online 14 March 2009 Crown Copyright ª 2009 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jinf.2009.02.003
Phylogenetic analysis of human bocavirus (HBoV) detected from children with acute respiratory infection in Japan
Dear Editor Human bocavirus (HBoV) belongs to family Parvoviridae and causes acute respiratory infection (ARI) in humans.1 HBoV is an emerging virus discovered by Allander et al. in 2005 from a Swedish patient with ARI.2 Although the clinical course of HBoV infection in most patients is good, it is suggested that HBoV is associated with lower respiratory infection including bronchiolitis and pneumoniae3e5; however, its epidemiology remains poorly understood at present.3 In this study, in an attempt to clarify the epidemiology, we performed phylogenetic analysis of HBoV detected from Japanese children with ARI in recent years. We obtained 7 amplicons of HBoV from patients (age range, 6 monthse2 years) with ARI. Their inhabitant areas were Yamagata prefecture (3 patients), Shiga prefecture (2 patients), Fukushima prefecture (1 patient), and Tokyo metropolitan (1 patient). We initially extracted DNA from throat swabs and amplified the full-length HBoV genome as previously described.6 The obtained amplicons were then sequenced and aligned.6 We next performed phylogenetic analysis, after which evolutionary distances were estimated using Kimura’s two-parameter method and phylogenic trees were constructed using the neighbor-joining (N-J) method.6 As shown in Fig. 1, 6 strains (3 from upper respiratory infection, 1 from bronchiolitis, and 2 from pneumonia)