INTRODUCTION
Despite the use of interventions such as antimicrobial drugs and
vaccination against leading pneumonia-causing pathogens, acute
respiratory infections (ARI) remain a major cause of death globally,
especially among children aged <5 years [11World
Health Organisation. Global Health estimates 2016: Deaths by cause,
age, sex, by country, Region, 2000-2016. 2018 . Available at:
www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death.
Accessed 29 January 2020]. In addition, mild and severe-non-fatal
episodes of ARI are responsible for a substantial burden on the
healthcare systems and the society, through illness, absenteeism, and
associated costs.
The Pneumonia Etiology Research for Child Health (PERCH) study conducted
in 7 low- and middle-income countries, including South Africa, estimated
that respiratory viruses were responsible for 61% of severe pneumonia
cases (compared to 27% due to bacteria) among HIV-uninfected children
aged <5 years
[22Pneumonia Etiology
Research for Child Health (PERCH) Study Group.
Causes of severe
pneumonia requiring hospital admission in children without HIV
infection from Africa and Asia: the PERCH multi-country case-control
study. Lancet. 2019 ;394(10200):757-779. doi:
10.1016/S0140-6736(19)30721-4.]. This suggests that, as bacterial
etiologies decline due to vaccination, respiratory viral causes may gain
greater prominence [2]. Nonetheless, the relative contribution of
respiratory viruses in individuals of all ages remains poorly
understood.
HIV infection is associated with increased severity of ARI and higher
case-fatality ratios, especially in older children and younger adults
[33Cohen
C, Walaza
S, Moyes
J, at al. Epidemiology of viral-associated acute lower respiratory
tract infection among children <5 years of age in a high HIV
prevalence setting, South Africa, 2009-2012. Pediatr Infect Dis J.2015 ;34(1):66-72. doi: 10.1097/INF.0000000000000478.,44Cohen
C, Walaza
S, Moyes
J, et al. Epidemiology of severe acute respiratory illness (SARI)
among adults and children aged ≥5 years in a high HIV-prevalence
setting, 2009-2012. PLoS One. 2015 ;10(2):e0117716. doi:
10.1371/journal.pone.0117716.]. In South Africa, a country with an
HIV prevalence of 12.7% in the general population and 23.5% in
individuals aged 25-44 years in 2016 [55Statistics South
Africa. Mid-Year Population Estimates. Pretoria, South Africa:
Statistics South Africa. 2016 . Available at:
https://www.statssa.gov.za/publications/P0302/P03022016.pdf.
Accessed 29 January 2020.], pneumonia and influenza were the
leading causes of death among children aged <5 years and the
3rd and 5th causes of death among
older individuals, resulting in 19,638 deaths annually in the same year
[66Statistics South Africa. Mortality and causes of death in
South Africa. 2016 . Available at:
https://www.statssa.gov.za/publications/P03093/P030932016.pdf.
Accessed 29 January 2020.]. Whereas the etiology of hospitalized
severe pneumonia among HIV-uninfected children aged <5 years
has been described in South Africa [2], the overall burden on the
healthcare system and society of mild and severe respiratory illness
overall and associated with respiratory viruses across age groups has
not been quantified. Quantifying this burden may assist policy makers
with allocation of resources and prioritization of interventions.
In this study, we sought to assess the mean annual national burden of
medically and non-medically attended influenza-like illness (ILI) and
severe respiratory illness (SRI) overall and associated with nine
respiratory viruses in different age groups in South Africa during
2013-2015.