Abstract Title
Detection of caliciviruses in older children, adults and the elderly in selected sentinel sites in South Africa, 2018-2024
Presenter
Nicola Page, National Institute for Communicable Diseases
Co-Author(s)
Nicola Page1,2,3, Sandrama Nadan1, Siobhan Johnstone4, Tersia Kruger1, Rembuluwani Netshikweta1, Nadia Strydom1, Phuti Sekwadi1, Michelle J. Groome4
1Centre for Enteric Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg, South Africa
2Department of Medical Virology, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
3School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
4South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Abstract Category
Epidemology
Abstract
Research investigating diarrhoeal aetiology in older individuals in South Africa is limited. This study examined calicivirus detection in participants ≤6 years at selected sentinel sites (2018 – 2024).
Participants (n=906) with acute diarrhoea were enrolled from hospitals and clinics. Stool specimens were screened for caliciviruses (FastTrack Diagnostics Viral Gastroenteritis; Siemens Healthcare GmbH; Erlangen, Germany). Diarrhoea-free unmatched hospitalized controls (n=183) were enrolled from three sites (2019 – 2022). Calicivirus prevalence was compared in cases and controls with odds ratio and 95% confidence intervals (p < 0.05) calculated using epitab; STATA version 12 (StataCorp LP, College Station, TX). Calicivirus prevalence was compared in people living with HIV (PLHIV) and HIV-uninfected participants using logistic regression and in hospital vs. clinics using ttest with unequal variance.
NoVGII was detected in 7% of participants (59/906), 4% (7/183) of controls, SaV in 2% (19/906) of cases, 1% (2/183) of controls and NoVGI in 2% (19/906) of cases, 3% (5/183) of controls. Caliciviruses were not significantly associated with diarrhoea in cases vs. controls. Odds of NoVGII detection were 2.0 (95% CI 1.2-3.6) in PLHIV (9%; 35/397) compared to HIV-uninfected participants (5%; 20/443; p=0.01) with NoVGII cases detected frequently in hospital (10%; 42/422) vs. clinic settings (4%; 17/464; p >0.01). NoVGI and SaV were frequent in mixed pathogen infections (NoVGI 12%; 14/121 and SaV 15%; 18/121).
NoVGII was detected at higher prevalence in PLHIV and in hospitalized patients. Continued surveillance of NoVGII strains is recommended in PLHIV. NoVGI and SaV tended to be milder with detection in mixed pathogen infections.
Participants (n=906) with acute diarrhoea were enrolled from hospitals and clinics. Stool specimens were screened for caliciviruses (FastTrack Diagnostics Viral Gastroenteritis; Siemens Healthcare GmbH; Erlangen, Germany). Diarrhoea-free unmatched hospitalized controls (n=183) were enrolled from three sites (2019 – 2022). Calicivirus prevalence was compared in cases and controls with odds ratio and 95% confidence intervals (p < 0.05) calculated using epitab; STATA version 12 (StataCorp LP, College Station, TX). Calicivirus prevalence was compared in people living with HIV (PLHIV) and HIV-uninfected participants using logistic regression and in hospital vs. clinics using ttest with unequal variance.
NoVGII was detected in 7% of participants (59/906), 4% (7/183) of controls, SaV in 2% (19/906) of cases, 1% (2/183) of controls and NoVGI in 2% (19/906) of cases, 3% (5/183) of controls. Caliciviruses were not significantly associated with diarrhoea in cases vs. controls. Odds of NoVGII detection were 2.0 (95% CI 1.2-3.6) in PLHIV (9%; 35/397) compared to HIV-uninfected participants (5%; 20/443; p=0.01) with NoVGII cases detected frequently in hospital (10%; 42/422) vs. clinic settings (4%; 17/464; p >0.01). NoVGI and SaV were frequent in mixed pathogen infections (NoVGI 12%; 14/121 and SaV 15%; 18/121).
NoVGII was detected at higher prevalence in PLHIV and in hospitalized patients. Continued surveillance of NoVGII strains is recommended in PLHIV. NoVGI and SaV tended to be milder with detection in mixed pathogen infections.