Human bocavirus: a novel parvovirus epidemiologically associated with pneumonia requiring hospitalization in Thailand

Abstract

Background: We detected human bocavirus (HBoV) infection in 4.5% of hospitalized patients with pneumonia in rural Thailand. However, the role of HBoV as a pathogen is unclear.

Methods: We compared HBoV infection in patients with pneumonia with that in asymptomatic control patients enrolled between 1 September 2004 and 31 August 2005 in the same hospitals in Thailand. We examined outpatients with influenza-like illness for HBoV infection and tested for 13 additional respiratory viruses. Epidemiologic and clinical characteristics of HBoV infection are described.

Results: HBoV infection was detected in 20 (3.9%) of 512 outpatients and 3 (1%) of 280 control patients. Coinfection with other viruses was detected in 83% of patients with pneumonia and in 90% of outpatients. Compared with control patients, HBoV infection was significantly associated with pneumonia requiring hospitalization (adjusted odds ratio, 3.56 [95% confidence interval, 1.06-11.91]; P=.04). Eighty-three percent of HBoV infections were detected in patients with pneumonia who were <5 years old. More patients with pneumonia associated with HBoV-respiratory syncytial virus (RSV) or human parainfluenza virus (HPIV) coinfections had wheezing than patients with RSV and HPIV infections alone (9 [53%] of 17 vs. 32 [23%] of 138]; P=.01).

Conclusions: HBoV infection was epidemiologically associated with pneumonia among young children in rural Thailand, but infection and illness may be dependent on coinfection with other viruses.

Table 1.

Human bocavirus (HBoV) polymerase chain reaction test results from hospitalized patients with pneumonia, asymptomatic control patients, and outpatients with acute respiratory illness from Sa Kaeo province, 1 September 2004–31 August 2005.

Table 2.

Viral coinfections among human bocavirus (HBoV)—infected hospitalized patients with pneumonia in Sa Kaeo province, Thailand.

Table 3.

Comparison of human bocavirus (HBoV) infections among patients hospitalized with pneumonia and asymptomatic control subjects in Sa Kaeo province, Thailand.

Figure 1.

Seasonal occurrence of human bocavirus (HBoV) infection among patients with pneumonia and outpatients with influenza-like illness, 1 September 2004–31 August 2005. HPIV, human parainfluenza virus; Rhino, rhinovirus; RSV, respiratory syncytial virus.

Table 4.

Comparisons of clinical characteristics among patients with pneumonia and human bocavirus (HBoV) infection, respiratory syncytial virus (RSV), and human parainfluenza virus (HPIV)—3 infection or HBoV-RSV and HBoV-HPIV3 coinfections.