Human metapneumovirus-associated severe acute respiratory illness hospitalisation in HIV-infected and HIV-uninfected South African children and adults

Abstract

Background: Data on human metapneumovirus (HMPV)-associated severe acute respiratory illness (SARI) are limited in settings with high human immunodeficiency virus (HIV) infection prevalence.

Objectives: To describe clinical characteristics and seasonality (all sites), and incidence (Soweto only) of HMPV-associated SARI among children and adults.

Study design: Active, prospective, hospital-based, sentinel surveillance for patients hospitalised with SARI was conducted at four sites in South Africa from February 2009-December 2013. Upper respiratory tract samples were tested by multiplex real-time polymerase chain reaction assays for HMPV and other respiratory viruses. Incidence of hospitalisation, stratified by age and HIV-infection status, was calculated for one hospital with population denominators.

Results: HMPV was identified in 4.1% of patients enrolled, including 5.6% (593/10503) in children and 1.7% in adults (≥18 years; 119/6934). The majority of adults (84.0%) had an underlying medical condition, including HIV infection in 87/110 (79.1%). HMPV detection occurred perennially with periods of increased detection, which varied from year to year. The incidence of HMPV-associated hospitalisation in Soweto was highest in infants (653.3 per 100,000 person years; 95% confidence interval (CI) 602.2-707.6). The incidence was higher in HIV-infected persons compared to HIV-uninfected persons in age-groups 5-17 years (RR 6.0; 1.1-20.4), 18-44 years (RR 67.6; 38.0-132.6) and 45-64 years (RR 5.3; 3.4-8.3), while not differing in other age-groups.

Conclusions: The burden of HMPV-associated SARI hospitalisation among adults occurred predominantly in HIV-infected persons. Among children, infants were at highest risk, with similar burden of hospitalisation in HIV-infected and HIV-uninfected children.

Keywords: HIV; Human metapneumovirus; Lower respiratory tract infection.

Fig. 1.

Incidence of hospitalisation (per 100,000 person years) by age group and year for HMPV-associated severe acute respiratory illness in Soweto, South Africa: 2009–2012.

Fig. 2.

Detection rate of HMPV, RSV and Influenza virus (A and B) among patients hospitalised for severe acute respiratory illness at all sites, by month and year: 2009–2013. Detection rate – number testing positive divided by total number of samples tested per month × 100. Footnote: In 2013 enrolment at Chris Hani Baragwanath Academic Hospital was down-scaled, with enrolment of paediatric patients limited to two of the five working days and adult patients to one of the five working days. Enrolment in 2013 at the other five hospitals continued as previously, with enrolment from Monday through Friday.

Fig. 3.

Number and proportion (n; %) of HMPV-positive patients with HMPV detected as the sole virus, co-detection of HMPV and one other respiratory virus (as specified), and co-detection of HMPV and >1 other respiratory virus in (a) children <18 years (b) adults ≥18 years. Note: Co-detection of HMPV and other respiratory viruses is detailed in the Supplementary material.