Respiratory viruses in rural Zambia before and during the COVID‐19 pandemic

Abstract

Objectives: With the emergence of the COVID-19 pandemic, restrictions were implemented globally to control the virus. Data on respiratory pathogens in sub-Saharan Africa during the COVID-19 pandemic are scarce. This analysis was conducted to evaluate patterns of respiratory pathogens in rural Zambia before and during the first year of the pandemic. Methods: Surveillance was established in December 2018 at Macha Hospital in southern Zambia. Patients with respiratory symptoms in the outpatient and inpatient clinics were recruited. Nasopharyngeal samples were collected and tested for respiratory pathogens. The prevalence of respiratory symptoms and pathogens was evaluated and compared in the first (December 10, 2018-December 9, 2019) and second (December 10, 2019-November 30, 2020) years of surveillance. Results: Outpatient visits and admissions for respiratory illness significantly decreased from the first to second year, especially among children. SARS-CoV-2 was not detected from any participants in Year 2. Among outpatients and inpatients with respiratory symptoms, the prevalence of respiratory syncytial virus and influenza viruses decreased from the first to second year. In contrast, the prevalence of rhinovirus/enterovirus, metapneumovirus and parainfluenza virus increased. Conclusions: The epidemiology of respiratory viruses in rural Zambia changed during the first year of the COVID-19 pandemic, suggesting that public health interventions may have had an impact on the introduction and circulation of respiratory pathogens in this area.

Circulation of respiratory viruses during the COVID-19 pandemic in The Gambia

“…In Canada, the average weekly positivity rate for influenza A in 2020-2021 was 0.012% compared to 10.40% in pre-pandemic years, and 0.006% for influenza B compared to 2.60% in pre-pandemic years 1 . Data from other African countries are scarce, with influenza and RSV reductions observed in South Africa and Zambia 13,14 , but not in the Democratic Republic of the Congo (5.6% influenza A positivity and 0.9% influenza B positivity Dec 2020 -March 2021) 15 . Interestingly, the reduction in RSV and influenza in Zambia during the first year of the COVID-19 pandemic was accompanied by increases in rhino/enteroviruses, seasonal coronaviruses, parainfluenza viruses and human metapneumovirus 14 .…”

Respiratory adenovirus infections in children: a focus on Africa

“…Consequently, HAdV has been less impacted by the implementation and easing of public health measures during the COVID-19 pandemic: a Zambian study reported HAdV being identified at higher rates from nasopharyngeal samples throughout the 2020-2021 period of the COVID-19 pandemic, compared to before the pandemic [ 21 ]. Interestingly, this heightened presence of adenovirus was observed a year into the pandemic rather than in its early stages [ 22 ], suggesting a nuanced temporal dynamic that may be related to the virus gradually occupying a specific ecological niche [ 23 , 24 ].…”

Respiratory viruses in rural Zambia during the second year of the COVID-19 pandemic

“…Limited data are available from sub-Saharan Africa, despite children and adults in this region experiencing significant morbidity and mortality from respiratory infections [5] . Surveillance from South Africa and Zambia reported decreases in influenza viruses and RSV following implementation of public health measures in 2020 [6 , 7] , but to date no studies have reported trends for respiratory infections following easing of restrictions.…”

“…Surveillance is ongoing, thereby providing the opportunity to compare the respiratory pathogen landscape before and during the COVID-19 pandemic in this area. The objective of this analysis was to evaluate the burden and patterns of respiratory viruses in rural Zambia in 2021 compared to previously reported data from 2019 and 2020 [7 , 8] .…”