Human bocavirus among infants and young children with acute viral lower respiratory tract infections

Abstract EN

Background : Acute viral infections of the lower respiratory tract are leading causes of hospitalization in infants and young children in developed countries and are major causes of death in developing countries.

Aims : To detect the frequency of Human Bocavirus (HBoV) infection among Egyptian infants and young children with acute viral lower respiratory tract infections and to identify the age group at risk, seasonal distribution and the characteristic clinical manifestations of this infection.

Methods : This study was done in the Pediatric hospital of Ain Shams University during the period from October 2005 to August 2007 and included 147 patients who were diagnosed as having acute viral infections of the lower respiratory tract.

The patients were 98 males and 49 females with age range between 1 month - 6 years and a mean age of 2.4 + 0.4 years.

Patients who had evidences of bacterial infections and those with underlying chronic illnesses were excluded from the study.

All patients included in the study were subjected to full history taking, thorough clinical examination, chest radiographs, complete blood count and CRP assessment in serum.

Nasopharyngeal aspirates from all patients were subjected to 2 rounds of PCR targeting 2 gene regions (NP-1 and NS-1) of HBoV.

Results: Human Bocavirus was detected in 13 out of the 147 patients having acute viral infections of the lower respiratory tract (8.8 %) and their clinical diagnoses were bronchiolitis in 2 (15.4 %), bronchitis in 2 (15.4 %), wheezy bronchitis in 4 (30.7 %) and pneumonia in 5 (38.5%) cases.

The patients positive for HBoV were 10 (76.9 %) males and 3 (23.1 %) females and their mean age was 15.1 + 11.4 months (range between 7-48 months).

Regarding the clinical manifestations of these patients, fever and cough were present in all cases, dyspnea was present in 11 (84.6 %), wheezes in 10 (76.9 %), diarrhea in one (7.7 %) and rash in one (7.7 %).

Chest X- rays showed abnormalities in 7 (53.8 %) out of the 13 patients positive for HBoV.

The mean duration of hospitalization for the 13 patients was 6.5 + 1.7 days (range 4-9 days).

Seasonal variations revealed that seven cases (53.8 %) occurred in winter; 3 (23 %) in autumn; 2 (15.4 %) in early spring and one case (7.8 %) in summer.

Conclusion: In conclusion, HBoV is present in Egypt among children with lower respiratory tract infection with the highest frequency between 7-48 months of age, male predominance and preference to cold seasons.

The ability to detect primary infection through the development of improved diagnostic methods will be of great importance for future >.s$udies seeking to assign a role for HBoV in causing respiratory illnesses.