ORIGINAL ARTICLE | ARTIGO ORIGINAL | ARTÍCULO ORIGINAL Ocurrence of Human Bocavirus associated with acute respiratory infections in children up to 2 years old in the City of Belém, Pará State, Brazil Ocorrência de Bocavírus Humano associado às infecções respiratórias agudas em crianças de 0 a 2 anos de idade na Cidade de Belém, Pará, Brasil La aparición de Bocavirus Humano asociado con las infecciones respiratorias agudas en niños de 0 a 2 años de edad en Belém (Estado de Pará, Brasil) Correspondência / Correspondence / Correspondencia: Allan Kaio Silva Universidade Federal do Pará Núcleo de Medicina Tropical E-mail: alansilva@iec.pa.gov.br http://revista.iec.pa.gov.br Allan Kaio Silva Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil Mirleide Cordeiro dos Santos Instituto Evandro Chagas/SVS/MS, Ananindeua, Pará, Brasil Wyller Alencar de Mello Instituto Evandro Chagas/SVS/MS, Ananindeua, Pará, Brasil Rita Catarina Medeiros de Sousa Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil INTRODUCTION Due to their high mortality, Acute Respiratory Infections (ARI) are still one of the main public health problems 7,28 worldwide, especially in developing countries . These infections are generally associated with various pathogens 6,13 with viruses being the most prevalent . Among these viruses are Influenza A and B (Flu A and Flu B), Parainfluenza 1, 2 and 3 (HPIV), Adenovirus (AdV), Respiratory Syncytial Virus (RSV), Human Rhinovirus (HRV), Coronavirus (HCoV) and Human Metapneumovirus 3,18 (hMPV) . Several studies are currently being conducted in order to determine the etiology of respiratory tract infections. In 12% to 39% of cases, no known agent is found. Under this 2 premise, Allander et al have described the development of a novel methodology based on molecular biology techniques in order to investigate new agents possibly related to respiratory tract infections. Using this methodology, these authors detected a parvovirus, previously called Human Bocavirus (HBoV), which is taxonomically classified within the genus Bocavirus, 2,14 subfamily Parvovirinae, family Parvoviridae . HBoV is a non-enveloped virus with icosahedral symmetry, a diameter of 18 to 26 nanometers and a capsid formed by approximately 60 capsomeres. The viral genome is non-segmented, composed of a single-stranded deoxyribonucleic acid (DNA) of both positive and negative sense and is approximately 5.3 Kb. The virus has three open reading frames (ORFs) that encodes four proteins: VP1 and VP2, virion structural proteins; NS1, non-structural protein; 87 Rev Pan-Amaz Saude 2010; 1(1):87-92 doi: 10.5123/S2176-62232010000100013 ABSTRACT INTRODUCTION: Acute Respiratory Infections (ARI) are one of the main public health problems in the world. Most of these infections are associated with several pathogens, and viruses are the most prevalent agents. Recently, a new parvovirus named Human Bocavirus (HBoV) has been described. Investigations on the relationship between this new agent and cases of ARI in individuals are still scarce. Herein, we review a study of HBoV in a population segment in the Amazon. MATERIALS AND METHODS: In this study, samples of nasopharyngeal aspirates from patients with ARI treated in Health Care Units in Belém, Brazil, were analyzed. Identification of the virus was carried out by polymerase chain reaction using pairs of specific oligonucleotides, followed by phylogenetic analysis of the nucleotide sequences obtained. RESULTS: Of the 397 samples studied, three specimens were HBoV-positive, and one presented as a co-infection with the respiratory syncytial virus. DISCUSSION: The positivity rate obtained in this investigation was lower than that described in other studies; however, previous studies involved hospitalized patients, which constitute a different population group. The phylogenetic analyses revealed a significant similarity between the virus strains found and those previously described. CONCLUSION: This is the first report associating HBoV with ARI in the Amazon. Keywords: Respiratory Tract Infections; Bocavirus; Parvoviridae Infections.