Influenza-associated pediatric deaths became a notifiable condition in the United States in 2004.
We analyzed deaths in children aged <18 years with laboratory-confirmed influenza virus infection reported to the Centers for Disease Control and Prevention during the 2010–2011 to 2015–2016 influenza seasons. Data were collected with a standard case report form that included demographics, medical conditions, and clinical diagnoses.
Overall, 675 deaths were reported. The median age was 6 years (interquartile range: 2–12). The average annual incidence was 0.15 per 100 000 children (95% confidence interval: 0.14–0.16) and was highest among children aged <6 months (incidence: 0.66; 95% confidence interval: 0.53–0.82), followed by children aged 6–23 months (incidence: 0.33; 95% confidence interval: 0.27–0.39). Only 31% (n = 149 of 477) of children aged ≥6 months had received any influenza vaccination. Overall, 65% (n = 410 of 628) of children died within 7 days after symptom onset. Half of the children (n = 327 of 654) had no preexisting medical conditions. Compared with children with preexisting medical conditions, children with none were younger (median: 5 vs 8 years old), less vaccinated (27% vs 36%), more likely to die before hospital admission (77% vs 48%), and had a shorter illness duration (4 vs 7 days; P < .05 for all).
Each year, influenza-associated pediatric deaths are reported. Young children have the highest death rates, especially infants aged <6 months. Increasing vaccination among children, pregnant women, and caregivers of infants may reduce influenza-associated pediatric deaths.
Comments
RE: Influenza-associated pediatric deaths in the United States, 2010-2016
The detailed epidemiology of influenza-associated pediatrics deaths presented by Shang et al. provides a strong summary of our recent experience with influenza mortality in children younger than 18 years.(1) One notable, but not surprising, finding caught our eye.
The highest mortality was seen in the youngest children – those under 6 months of age. Protecting our most vulnerable children – those who are too young to receive influenza vaccine – should be one of our key priorities. Administering influenza vaccination to pregnant women has been part of US immunization policy for nearly 60 years.(2) This was highlighted during the 2009 H1N1 influenza pandemic, during which influenza-associated hospitalizations and mortality were higher in pregnant women compared to non-pregnant women.(3) However, immunizing pregnant women against influenza also has protective benefits for their children, through passive transfer of antibodies prior to birth.(4)
Recognizing the documented effectiveness of maternal influenza vaccination in preventing young infant morbidity,(4) it is critical to our understanding of neonatal health to evaluate the impact of maternal influenza vaccination on mortality in early infancy. While reading this manuscript, we observed that maternal influenza vaccination status was not collected, and thus, unable to be analyzed. While the analysis presented here is focused on surveillance, and thus would be unable to assess the effectiveness of maternal immunization in preventing infant deaths, we believe that maternal influenza vaccination status should be included as a key surveillance measure in the Influenza Associated Pediatric Mortality Surveillance System.
Inclusion of maternal influenza vaccination status would provide a clearer assessment of young infant influenza-associated deaths. With maternal influenza vaccination coverage hovering around 50% since the 2012-2013 influenza season,(5) many young infants are not reaping the benefits of maternal vaccination. Given this, it is appropriate to track the proportion of infants born to mothers who did or did not receive influenza vaccine, to allow preliminary surveillance of the role of vaccination in preventing young childhood mortality.
1. Shang M, Blanton L, Brammer L, Olsen SJ, Fry AM. Influenza-Associated Pediatric Deaths in the United States, 2010-2016. Pediatrics. 2018.
2. Burney LE. Influenza Immunization: Statement. Public Health Rep. 1960;75(10):944. PMC1929542.
3. Callaghan WM, Creanga AA, Jamieson DJ. Pregnancy-Related Mortality Resulting from Influenza in the United States During the 2009-2010 Pandemic. Obstet Gynecol. 2015;126(3):486-490. PMC4557717.
4. Zaman K, Roy E, Arifeen SE, Rahman M, Raqib R, Wilson E, Omer SB, Shahid NS, Breiman RF, Steinhoff MC. Effectiveness of Maternal Influenza Immunization in Mothers and Infants. N Engl J Med. 2008;359(15):1555-1564.
5. Ding H, Black CL, Ball S, Fink RV, Williams WW, Fiebelkorn AP, Lu PJ, Kahn KE, D'Angelo DV, Devlin R, Greby SM. Influenza Vaccination Coverage among Pregnant Women - United States, 2016-17 Influenza Season. MMWR Morb Mortal Wkly Rep. 2017;66(38):1016-1022. PMC5657675.