Table 3.
Characteristics of Hospitalized Pregnant and Postpartum Women With Known Influenza Vaccination Status Who Tested Influenza Positive or Negative by Polymerase Chain Reaction—South Africa, 2015–2018
| Characteristic | Influenza-Positive Cases (n = 56) | Influenza-Negative Controls (n = 345) | P Value |
|---|---|---|---|
| Age at admission, y | |||
| Mean (SD) | 30.1 (6.6) | 29.6 (6.3) | .60 |
| 18–24 | 14 (25.0) | 86 (25.0) | .99 |
| 25–34 | 27 (48.2) | 167 (48.6) | |
| ≥35 | 15 (26.8) | 91 (26.5) | |
| HIV infection | |||
| Infected | 28 (50.0) | 148/344 (43.0) | .33 |
| Uninfected | 28 (50.0) | 196/344 (57.0) | |
| Race | |||
| Black African | 40 (71.4) | 267 (77.4) | .67 |
| South African Coloured | 15 (26.8) | 69 (20.0) | |
| White | 1 (1.8) | 6 (1.7) | |
| Asian | 0 (0) | 3 (0.9) | |
| Pregnancy trimester at admission | |||
| First | 1/55 (1.8) | 8/340 (2.4) | .54 |
| Second | 13/55 (23.6) | 77/340 (22.7) | |
| Third | 40/55 (72.7) | 231/340 (67.9) | |
| Postpartum | 1/55 (1.7) | 24/340 (7.1) | |
| Study site | |||
| Chris Hani Baragwanath Academic Hospital, Johannesburg | 13 (23.2) | 96 (27.8) | .81 |
| Rahima Moosa Mother and Child Hospital, Johannesburg | 21 (37.5) | 123 (35.7) | |
| Helen Joseph Hospital, Johannesburg | 2 (3.6) | 12 (3.5) | |
| Groote-Schuur Hospital, Cape Town | 5 (8.9) | 34 (9.9) | |
| Mowbray Hospital, Cape Town | 10 (18.9) | 40 (11.6) | |
| Mitchell's Plain Hospital, Cape Town | 5 (8.9) | 40 (11.6) | |
| Comorbidity | |||
| Yes | 13 (23.2) | 59 (17.1) | .27 |
| No | 43 (76.8) | 286 (82.9) | |
| Smoker | |||
| Yes | 4 (7.1) | 31 (9.0) | .80 |
| No | 52 (92.9) | 314 (91.0) | |
| Alcohol consumption | |||
| Yes | 2 (3.6) | 16 (4.6) | .99 |
| No | 54 (96.4) | 329 (95.4) | |
| Period of influenza season | |||
| Early | 24 (42.9) | 134 (38.8) | .72 |
| Middle | 20 (35.7) | 120 (34.8) | |
| Late | 12 (21.4) | 91 (26.4) | |
| Year of enrollment | |||
| 2015 | 4 (7.1) | 34 (9.9) | .56 |
| 2016 | 19 (33.9) | 91 (26.4) | |
| 2017 | 15 (26.8) | 85 (24.6) | |
| 2018 | 18 (32.1) | 135 (39.1) | |
| Influenza vaccination during pregnancy >13 d before admission | |||
| Yes | 16 (28.6) | 132 (38.3) | .16 |
| No | 40 (71.4) | 213 (61.7) |
Values are presented as No. (%) unless stated otherwise. The number of participants with available information is indicated (no./No.) if different from the total number of participants.
Abbreviations: HIV, human immunodeficiency virus; SD, standard deviation.