Seasonality, Incidence, and Repeat Human Metapneumovirus Lower Respiratory Tract Infections in an Area With a High Prevalence of Human Immunodeficiency Virus Type-1 Infection

BACKGROUND: There is limited information regarding the epidemiology of human metapneumovirus (hMPV) from Africa, despite it being identified as a common pathogen in children with pneumonia. OBJECTIVES: Determine the epidemiology of severe hMPV-associated lower respiratory tract infection (LRTI) in human immunodeficiency virus type-1 (HIV) infected and uninfected children. METHODS: Nasopharyngeal aspirate samples from children hospitalized for LRTI between January 2000 and December 2002 were analyzed for common respiratory viruses using an immunofluorescence assay; and 2715 available nasopharyngeal aspirate samples were tested for hMPV by reverse-transcriptase polymerase chain reaction targeting its fusion protein. Phylogenetic analysis of the fusion (F) gene was performed on samples associated with repeat hMPV infections in the same child. RESULTS: hMPV was identified perennially and was the second most commonly identified respiratory virus (11.3% versus 21.1% for respiratory syncytial virus, P < 0.0001) in HIV-uninfected children. The burden of hospitalization for hMPV-LRTI was 5.4 (95% CI: 3.5-7.5) fold greater in HIV-infected (2935 per 100,000) compared with HIV-uninfected children 575 (95% CI: 472-695) per 100,000. HIV-infected children had greater evidence of bacterial coinfection and a higher mortality rate than did uninfected children. Repeat hMPV associated hospitalizations involved homologous (B2 subgroup) and heterologous (A1 and B2) hMPV. CONCLUSIONS: There is a high burden of hMPV-LRTI and repeat severe infections occur from homologous and heterologous subgroups of the virus.