Acute respiratory infection is the major cause of morbidity and mortality worldwide, several types of viruses associated with this disease. This study aims to determine the infection rate of human bocavirus in children with lower respiratory tract infection and identify the genotyping among study population. Cross sectional study which consists of 122 children under five years old suffering from lower respiratory tract infection (75 males and 47 females); their aged from range 1 month to 60 months. They were attending respiratory wards in Fatima Al-Zahraa Hospital, Al-Elwiya Pediatrics Hospital, Ibn Al-Baladi Hospital and Pediatrics Protection Hospital in Baghdad, during the period from December 2017 to February 2018. Nasopharyngeal samples were collected from each participant, then used for DNA extraction and amplification with specific primers. Out of all 122 samples, eight samples were positive for HBoV (6.6%). Most infection were recorded in males 5(62.5%) and patients in age group 1-30 months 7(87.5%). The results of phylogenetic analysis for HBoV DNA isolated from nasopharyngeal swabs revealed all local isolates (8 isolates) are with HBoV type 1, half of the local isolates (4) were closed to Iranian isolation and the other four were closed to isolates from different regions (Tunisia, Italy and Argentina isolation). Some variant in amino acid noticed after alignment to the local isolates with some Gene Bank isolates and deletion of amino acid occur in isolates number one and five in more than two position, but the substitution revealed in isolate number six in three position. In conclusion, infection rate of HBoV-1 comparable with result of neighboring countries, local isolate of HBoV-1 have their characteristic genetic structure which differentiation them from other international isolate.

Keywords: Acute respiratory infection, Human bocavirus, Molecular detection, Viral sequence.