TABLE 2. Characteristics of children and adolescents aged <18 years who died with influenza and influenza and SARS-CoV-2 coinfections (N = 44) — Influenza-Associated Pediatric Mortality Surveillance System, United States, October 3, 2021–October 1, 2022*.
| Characteristic | No. of patients (%) with influenza and SARS-CoV-2 coinfection (n = 7) | No. of patients (%) with only influenza (n = 37) | p-value† |
|---|---|---|---|
|
Age, yrs, median (IQR)
|
6 (2–13) |
4 (1–8) |
0.34 |
|
Age group, yrs
| |||
| 0–4 |
2 (28.6) |
21 (56.8) |
0.41 |
| 5–11 |
3 (42.9) |
9 (24.3) |
|
| 12–17 |
2 (28.6) |
7 (18.9) |
|
|
Sex
| |||
| Male |
4 (51.7) |
15 (40.5) |
0.44 |
| Female |
3 (42.9) |
22 (59.5) |
|
|
Race and ethnicity
| |||
| American Indian or Alaska Native, non-Hispanic |
0 (—) |
1 (2.8) |
0.66 |
| Asian or Pacific Islander, non-Hispanic |
0 (—) |
1 (2.8) |
|
| Black or African American, non-Hispanic |
0 (—) |
6 (16.7) |
|
| Hispanic or Latino |
2 (33.3) |
8 (22.2) |
|
| White, non-Hispanic |
4 (66.7) |
18 (50.0) |
|
| Multiracial |
0 (—) |
2 (5.6) |
|
|
Influenza vaccination status
§
| |||
| Fully vaccinated |
0 (—) |
5 (16.1) |
0.57 |
| Not fully vaccinated |
6 (100.0) |
26 (83.9) |
|
| Ineligible |
0 (—) |
2 |
|
|
Influenza test type
¶
| |||
| Rapid antigen |
2 (28.6) |
9 (24.3) |
0.66 |
| RT-PCR |
5 (71.4) |
31 (83.8) |
|
|
Influenza type
| |||
| A |
6 (85.7) |
36 (97.3) |
0.30 |
| B |
1 (14.3) |
1 (2.7) |
|
| A and B |
0 (—) |
0 (—) |
— |
|
Other viral coinfection**
|
1 (14.3) |
1 (2.7) |
0.33 |
|
ACIP-defined high-risk condition
††
| |||
| Yes |
4 (80.0) |
21 (58.3) |
0.63 |
| No |
1 (20.0) |
15 (41.7) |
|
|
Type of ACIP-defined high-risk condition
§§
| |||
| Neurologic disorders |
2 (40.0) |
12 (33.3) |
— |
| Cardiac and congenital heart diseases |
0 (—) |
4 (11.1) |
— |
| Pulmonary diseases (including asthma and cystic fibrosis) |
3 (60.0) |
5 (13.9) |
— |
| Endocrine diseases (including diabetes mellitus) |
1 (20.0) |
2 (5.6) |
— |
| Premature at birth |
0 (—) |
2 (5.6) |
— |
| Immunosuppressive conditions |
0 (—) |
1 (2.8) |
— |
| Renal diseases |
1 (20.0) |
0 (—) |
— |
| Genetic disorders |
2 (40.0) |
6 (16.7) |
— |
| Mitochondrial disorders |
0 (—) |
1 (2.8) |
— |
| Obesity |
0 (—) |
2 (5.6) |
— |
|
Received influenza antiviral treatment
¶¶
|
1 (14.3) |
17 (45.9) |
0.21 |
|
Hospitalized
| |||
| Yes |
4 (57.1) |
21 (56.8) |
1.00 |
| No |
3 (42.9) |
16 (43.2) |
|
|
Invasive mechanical ventilation
| |||
| Yes |
2 (50.0) |
20 (95.2) |
0.06 |
| No |
2 (50.0) |
1 (4.8) |
|
|
Any complication
| |||
| Yes |
7 (100.0) |
27 (84.4) |
0.56 |
| No |
0 (—) |
5 (15.6) |
|
|
Complications
| |||
| Pneumonia |
3 (42.9) |
9 (28.1) |
0.41 |
| Acute respiratory distress syndrome |
2 (28.6) |
6 (18.8) |
0.61 |
| Croup |
0 (—) |
2 (6.3) |
1.00 |
| Seizures |
0 (—) |
7 (21.9) |
0.32 |
| Bronchiolitis |
2 (28.6) |
4 (12.5) |
0.28 |
| Encephalopathy or encephalitis |
0 (—) |
4 (12.5) |
1.00 |
| Cardiomyopathy or myocarditis |
0 (—) |
5 (15.6) |
0.57 |
| Hemorrhagic pneumonia or pneumonitis |
0 (—) |
1 (3.1) |
1.00 |
| Reye syndrome |
0 (—) |
0 (—) |
— |
| Shock |
1 (14.3) |
5 (15.6) |
1.00 |
| Sepsis |
0 (—) |
5 (15.6) |
0.56 |
| Other complications |
3 (42.9) |
13 (40.6) |
1.00 |
|
Days from illness onset to death
| |||
| ≤1 |
1 (20.0) |
3 (9.7) |
0.78 |
| 2–7 |
3 (60.0) |
20 (64.5) |
|
| >7 |
1 (20.0) |
8 (25.8) |
|
|
Death location
| |||
| ED |
1 (14.3) |
7 (18.9) |
1.00 |
| ICU |
4 (57.1) |
19 (51.3) |
|
| Inpatient ward |
0 (—) |
2 (5.4) |
|
| Outside of hospital | 2 (28.6) | 9 (24.3) | |
Abbreviations: ACIP = Advisory Committee on Immunization Practices; ED = emergency department; ICU = intensive care unit; RT-PCR = reverse transcription–polymerase chain reaction.
* Data on race and ethnicity were unknown for one patient with influenza and SARS-CoV-2 coinfection and one (2.7%) patient with only influenza; data on current season influenza vaccine were unknown for one patient with influenza and SARS-CoV-2 coinfection and four (10.8%) patients with only influenza; data on ACIP-defined high-risk conditions were unknown for two patients with influenza and SARS-CoV-2 coinfection and one (2.7%) patient with only influenza; data on invasive mechanical ventilation were unknown for one patient with influenza and SARS-CoV-2 coinfection and one (2.7%) patient with only influenza; data on any complications was unknown for five (13.5%) patients with only influenza; data on days from illness onset to death were unknown for two patients with influenza and SARS-CoV-2 coinfection and six (16.2%) patients with only influenza.
† Medians were compared using a Wilcoxon rank sum test. Proportions were compared using Fisher’s exact tests.
§ Fully vaccinated is defined as immunization in a person aged ≥9 years who received ≥1 dose of current season’s vaccine ≥14 days from illness onset; or for a person aged 6 months–8 years who 1) received ≥1 dose of current season’s vaccine ≥14 days from illness onset, and 2) received ≥2 total doses in their lifetime (2 doses of current season’s vaccine, both ≥14 days from illness onset, or 1 dose of current season’s vaccine ≥14 days from illness onset plus 1 dose from a previous season). Not fully vaccinated: a person aged ≥6 months who did not receive any doses of the current season’s vaccine; or a person aged ≥6 months who received ≥1 dose of the current season’s vaccine, but the dose or final dose, if multiple doses, was ≤14 days from illness onset; or for a person aged 6 months–8 years who received only 1 dose of current season’s vaccine ≥14 days from illness onset, but received no other doses from a previous season. A person was considered ineligible if aged <6 months.
¶ Proportions for test types are not mutually exclusive.
** One child with a SARS-CoV-2 infection also received a positive test result for adenovirus, rhinovirus/enterovirus, and respiratory syncytial virus. One child with only influenza also received a positive adenovirus test result.
†† Children who have chronic pulmonary (including asthma and cystic fibrosis), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus); are immunocompromised for any reason; are receiving aspirin- or salicylate-containing medications and might be at risk for Reye syndrome after influenza virus infection; or who have extreme obesity.
§§ p-values not calculated because of small numbers.
¶¶ Influenza antiviral treatments included oseltamivir or peramivir.