Table 1.
Epidemiological and Clinical Differences Between Human Metapneumovirus Single Infection, Human Metapneumovirus Coinfections, and Respiratory Syncytial Virus Single Infection
| Variable | hMPV Single Infection (n = 235) | RSV Single Infection (n = 2204) | P Valuea | hMPV Coinfections (n = 148) | P Valueb |
|---|---|---|---|---|---|
| Infant variables | |||||
| Age, mo, mean (SD) | 7.7 (5.04) | 6.3 (5.21) | .0001 | 6.9 (5.13) | .119 |
| Male | 122 (55.36) | 1209 (68.97) | .378 | 90 (62.5) | .054 |
| Prematurityc | 34 (14.47) | 272 (12.34) | .350 | 15 (10.14) | .219 |
| Low birth weightd | 36 (15.32) | 269 (12.21) | .171 | 22 (14.86) | .904 |
| Breastfeeding | 199 (84.68) | 1967 (89.25) | .036 | 125 (84.46) | .953 |
| Comorbiditiese | 12 (5.11) | 86 (3.9) | .373 | 5 (3.38) | .427 |
| Complete immunization schedulef | 124 (57.14) | 1257 (59.29) | .427 | 79 (56.83) | .722 |
| Assistance to day care | 8 (3.56) | 96 (4.47) | .523 | 6 (4.2) | .755 |
| Malnutritiong | 2 (1.96) | 25 (3.77) | .365 | 2 (3.13) | .637 |
| Atopyh | 9 (4.02) | 97 (4.55) | .79 | 3 (2.14) | .296 |
| Familial variables | |||||
| Siblings with asthma | 33 (19.19) | 299 (19.14) | .628 | 27 (26.47) | .144 |
| Paternal asthma | 11 (4.93) | 108 (5.3) | .924 | 6 (4.29) | .364 |
| Maternal asthma | 12 (5.38) | 118 (5.51) | .279 | 6 (4.26) | .91 |
| Current maternal smoking | 61 (27.6) | 561 (26.56) | .818 | 34 (24.29) | .698 |
| Current paternal smoking | 48 (41.38) | 637 (45.18) | .672 | 28 (38.36) | .866 |
| Pregnancy variables | |||||
| Intrauterine growth retardation | 12 (5.53) | 87 (4.15) | .696 | 11 (7.91) | .761 |
| Teenage mother | 22 (9.36) | 206 (9.35) | .994 | 7 (4.73) | .101 |
| Elderly mother | 23 (9.79) | 257 (11.66) | .392 | 16 (10.81) | .747 |
| Smoking during pregnancy | 46 (20.44) | 450 (20.82) | .792 | 24 (17.02) | .408 |
| Socioeconomic variables | |||||
| Crowding | 125 (53.19) | 1041 (47.23) | .083 | 78 (52.7) | .926 |
| Precarious homei | 165 (70.21) | 1528 (69.33) | .780 | 100 (67.57) | .585 |
| Low maternal educationj | 28 (11.91) | 295 (13.38) | .528 | 19 (12.84) | .789 |
| Clinical features at admission | |||||
| Tachypnea | 57 (24.26) | 572 (25.95) | .572 | 54 (36.49) | .011 |
| Tachycardia | 53 (22.55) | 520 (23.59) | .721 | 51 (34.46) | .011 |
| Wheezing | 46 (19.57) | 549 (24.91) | .543 | 43 (29.05) | .033 |
| Chest retractions | 52 (22.13) | 469 (21.28) | .347 | 50 (33.78) | .012 |
| Clinical outcomes during admission | |||||
| Pneumonia | 21 (8.93) | 146 (6.62) | .184 | 7 (4.73) | .13 |
| Pneumothorax | 1 (.43) | 17 (.77) | .562 | … | … |
| Sepsis | 5 (2.13) | 30 (1.36) | .352 | 1 (.68) | .291 |
| Life-threatening diseasek | 25 (11.11) | 370 (18.26) | .008 | 14 (10.14) | .773 |
Data are No. (%) except where indicated. In bold those P values < .05.
Abbreviations: hMPV, human metapneumovirus; hMPV coinfection, hMPV-positive patient coinfected either with RSV, human rhinovirus, or influenza A viruses; hMPV single infection, hMPV-infected patient without coinfections; RSV, respiratory syncytial virus.
a P value: hMPV single infection versus RSV single infection.
b P value: hMPV single infection versus hMPV coinfections.
cPrematurity: <37 weeks of gestational age.
dLow birth weight: <2500 g at birth.
eComorbidities: severe neurologic disorder, congenital cardiopathy, hematologic disorder, or immunodeficiency.
fComplete immunization schedule: according to national immunization schedule, https://www.argentina.gob.ar/salud/vacunas.
gMalnutrition: % of the infant’s weight compared to that of a normal child (50th percentile of weight for age) of the same age under 90% according to World Health Organization child growth standards: http://www.who.int/childgrowth/standards/en.
hAtopy: physician-diagnosed allergic rhinitis or atopic dermatitis.
iPrecarious home: dirt floor, no sewage, heating unvented sources, lack of potable water, house material tin/mud.
jLow maternal education: incomplete primary school.
kLife-threatening disease: O2 saturation ≤ 87% on admission, requirement for mechanical ventilation, and/or admission to the intensive care unit.