Influenza increases invasive meningococcal disease risk in temperate countries

Abstract

Objectives: Invasive meningococcal disease (IMD) is a severe bacterial infection that displays wintertime seasonality in temperate countries. Mechanisms driving seasonality are poorly understood and may include environmental conditions and/or respiratory virus infections. We evaluated the contribution of influenza and environmental conditions to IMD risk, using standardized methodology, across multiple geographical regions. Methods: We evaluated 3276 IMD cases occurring between January 1999 and December 2011 in 11 jurisdictions in Australia, Canada, France and the United States. Effects of environmental exposures and normalized weekly influenza activity on IMD risk were evaluated using a case-crossover design. Metaanalytic methods were used to evaluate homogeneity of effects and to identify sources of betweenregion heterogeneity. Results: After adjustment for environmental factors, elevated influenza activity at a 2-week lag was associated with increased IMD risk (adjusted odds ratio (OR) per standard deviation increase 1.29; 95% confidence interval, 1.04e1.59). This increase was homogeneous across the jurisdictions studied. By contrast, although associations between environmental exposures and IMD were identified in individual jurisdictions, none was generalizable. Conclusions: Using a self-matched design that adjusts for both coseasonality and case characteristics, we found that surges in influenza activity result in an acute increase in population-level IMD risk. This effect is seen across diverse geographic regions in North America, France and Australia. The impact of influenza infection on downstream meningococcal risk should be considered a potential benefit of influenza immunization programmes.

Changes in the incidence of invasive disease due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis during the COVID-19 pandemic in 26 countries and territories in the Invasive Respiratory Infection Surveillance Initiative: a prospective analysis of surveillance data

“…For example, the high mortality of the 1918 influenza pandemic was strongly associated with post-viral pneumonia caused by S pneumoniae in the absence of antimicrobials to treat bacterial pneumonia. 8 , 9 , 10 , 11 , 12 Therefore, there is potential for increased rates of invasive bacterial diseases subsequent to SARS-CoV-2 infection. Alternatively, containment measures initiated in many countries to reduce viral transmission could result in decreased invasive disease due to a concomitant reduction in transmission of respiratory-associated bacteria.…”

The indirect impact of COVID-19 large-scale containment measures on the incidence of community-acquired pneumonia in older people: a region-wide population-based study in Tuscany, Italy

“…To accurately evaluate the potential reduction of the burden of respiratory infectious diseases, this phenomenon needs to be measured in large and well-defined populations. Furthermore, large time frames -such as a whole intra-epidemic period- need to be considered as the SARS-COV-2 infection in itself has the potential for increasing the incidence of bacterial pneumonia: viral respiratory infections are usually associated with an increased risk of subsequent bacterial infections ( Morens et al, 2008 ; Morens and Fauci 2007 ; Wolter et al, 2014 ; Salomon et al, 2020 ).…”

Population-based study of influenza and invasive meningococcal disease among Greek children during the COVID-19 pandemic

“…[8][9][10] Considering then, the known role of influenza infection as a risk factor for invasive meningococcal disease (IMD), one may postulate a concomitant decrease of the IMD incidence during the COVID-19 pandemic. 11 IMD usually presents as meningitis or septicaemia and mainly affects children younger than 2 years old and adolescents. It is caused by Neisseria meningitidis, which is transmitted from person to person through respiratory droplets from infected patients or carriers.…”