Q&A: How did the COVID-19 pandemic impact lower respiratory infection burden?
Published April 16, 2024
Measures to slow the spread of COVID-19 also worked to prevent other lower respiratory infections, like influenza and RSV. IHME Associate Professor Dr. Hmwe Hmwe Kyu shares new findings from the Global Burden of Disease study.
This transcript has been lightly edited for clarity
How does the addition of more than 10 new lower respiratory infection pathogens to the Global Burden of Disease study add to our understanding of the impact of LRIs globally?
In our recent study, we assessed a comprehensive list of pathogens causing non-COVID-19 lower respiratory infections, or LRIs. This included the addition of more than 10 new pathogens that were not accounted for in previous Global Burden of Disease studies.
This advancement was made possible through the Global Research on Antimicrobial Resistance project, which analyzed data from a variety of sources, including vital registration, hospital discharge, microbial laboratories, and published literature. Given that LRIs resulted in more than 2 million deaths each year, enhancing our understanding of the main pathogens could inform specific interventions to curb the burden of these infections.
What is the general trend in LRI mortality, and how does it differ between age groups?
LRI mortality rates have declined across all age groups since 1990, with the most significant reductions observed in children under 5. The progress in children can be attributed to interventions including pneumococcal and Haemophilus influenzae type b, or Hib, vaccinations, along with a reduction in exposure to risk factors such as undernutrition and indoor air pollution.
On the other hand, older adults have seen a much slower decline in LRI mortality. As people age, their immune function weakens, increasing their susceptibility to infections. They are also more likely to have comorbid conditions. Research has shown promising benefits of influenza and pneumococcal vaccine administration in older adults. However, access to these vaccines remains a considerable challenge in low- and middle-income countries.
What strategies are important to continue the decline in LRI mortality?
To sustain and enhance progress in reducing LRI mortality, we can categorize key interventions into three main areas: vaccination, reducing exposure to risk factors, and early diagnosis and treatment. Vaccination against key pathogens, including pneumococcus, Hib, and influenza, as well as the recently approved new vaccines against respiratory syncytial virus, or RSV, have the potential to greatly diminish LRIs. However, we also face challenges from pathogens that are not currently vaccine-preventable, such as Staphylococcus aureus and Klebsiella pneumoniae, where the increasing issue of antibiotic resistance complicates treatment.
Addressing antimicrobial resistance and developing affordable and new interventions for these pathogens are crucial. In addition, minimizing exposure to risk factors such as smoking and indoor and outdoor air pollution, as well as preventing child growth failure, could further reduce the LRI burden.
Looking at LRI infections and mortality globally, what picture emerges from your research?
Our study revealed that despite substantial progress in reducing incidence and mortality, these infections continue to pose a major health challenge, especially in low- and middle-income countries. A striking disparity is evident in children under 5, where LRI mortality rates in sub-Saharan Africa were more than 90 times higher than those in high-income regions in 2021. This pronounced difference highlights the critical need for interventions to minimize geographic disparities in health care access and vaccine coverage for vulnerable populations.
How did the COVID pandemic impact LRI infections and mortality?
Our analysis focused on assessing the COVID-19 pandemic’s impact on viral pathogens causing LRIs, specifically influenza and RSV. By analyzing monthly influenza surveillance data alongside RSV data from published studies during the pandemic, with the broad implementation of non-pharmaceutical interventions such as mask wearing and mobility restrictions, we estimated more than 60% reductions in influenza and RSV infections and associated deaths globally from 2019 to 2021.
Notably, findings from recent studies documenting a resurgence of these pathogens as mitigation measures were relaxed underscore the importance of continued health care vigilance and preparedness.