Volume 20, Number 7—July 2014
CME ACTIVITY - Research
Epidemiology of Influenza Virus Types and Subtypes in South Africa, 2009–20121
Table 2
Characteristics of patients hospitalized with influenza A(H1N1)pdm09-associated severe acute respiratory illness, by wave, 4 sites, South Africa, 2009–2012*
First wave (2009), no. pos/no. tested (% pos) | Second wave (2011), no. pos/no. tested (% pos) | |||
---|---|---|---|---|
Age group, y | ||||
<5 | 87/160 (54.4) | 67/140 (47.9) | Reference | Reference |
5–24 | 31/160 (19.4) | 12/140 (8.6) | 0.5 (0.2–1.1) | 0.6 (0.3–1.4) |
25–44 | 24/160 (15.0) | 42/140 (30.0) | 2.3 (1.3–4.1) | 2.8 (1.5–5.1) |
45–64 | 13/160 (8.1) | 16/140 (11.1) | 1.6 (0.7–3.6) | 2.0 (0.9–4.6) |
>65 |
5/160 (3.1) |
3/139 (2.1) |
0.8 (0.2–3.4) |
1.1 (0.3–5.1) |
Male |
76/159 (47.8) |
57/139 (41.1) |
0.8 (0.5–1.2) |
|
Black African |
156/159 (98.1) |
135/139 (97.1) |
1.5 (0.3–7.0) |
|
Site | ||||
Soweto | 104/160 (65.0) | 98/140 (70.0) | Reference | Reference |
Klerksdorp | Not applicable | 12/140 (8.6) | Not calculated | Not calculated |
Pietermaritzburg | 6/160 (3.8) | 12/140 (8.6) | 0.4 (0.2–0.7) | 0.4 (0.2–0.8) |
Agincourt |
50/160 (31.3) |
18/140 (12.9) |
2.1 (0.8–5.9) |
2.7 (0.96–7.8) |
Co-infections and underlying medical conditions | ||||
HIV-infected | 47/119 (39.5) | 49/117 (41.9) | 1.1 (0.7–1.9) | |
Tuberculosis | 18/158 (11.4) | 12/139 (8.6) | 0.7 (0.3–1.6) | |
Underlying medical condition excluding tuberculosis, HIV | 11/159 (6.9) | 15/139 (10.8) | 1.6 (0.7–3.7) | |
Pregnancy | 2/83 (2.4) | 0/82 (0) | Not calculated | |
Bacterial/viral respiratory co-infection | ||||
Pneumococcal co-infection detected by PCR | 15/129 (11.6) | 7/127 (5.5) | 0.4 (0.2–1.1) | |
Respiratory syncytial virus | 2/153 (1.3) | 11/140 (7.9) | 6.4 (1.4–29.6) | |
Adenovirus | 0/153 (0) | 18/140 (12.9) | Not calculated | |
Parainfluenzavirus 1, 2, or 3 | 10/160 (6.3) | 3/140 (2.1) | 0.3 (0.1–1.2) | |
Human metapneumovirus | 6/153 (3.9) | 1/140 (0.7) | 0.2 (0.0–1.5) | |
Rhinovirus | 16/153 (10.5) | 11/140 (7.9) | 0.7 (0.3–1.6) | |
Enterovirus |
2/153 (1.3) |
2/140 (1.4) |
1.1 (0.2–7.9) |
|
Clinical presentation and course | ||||
Temperature ≥38°C | 76/110 (69.1) | 46/139 (33.1) | 0.2 (0.1–0.4) | |
Cough† | 83/87 (95.4) | 66/67 (98.5) | 3.2 (0.3–29.1) | |
Tachypnea† | 32/84 (38.1) | 34/65 (52.3) | 1.8 (0.9–3.4) | |
Difficulty breathing† | 69/87 (79.3) | 45/67 (67.2) | 0.5 (0.3–1.1) | |
Chest wall indrawing† | 44/87 (50.6) | 25/67 (47.3) | 0.6 (0.3–1.1) | |
Stridor† | 4/87 (4.6) | 11/67 (16.4) | 4.1 (1.2–13.4) | |
Tachycardia† | 44/87 (50.6) | 43/67 (64.2) | 1.8 (0.9–3.4) | |
Diarrhea† | 16/87 (18.4) | 9/67 (13.4) | 0.7 (0.3–1.7) | |
Unable to eat† | 29/87 (33.3) | 11/67 (6.4) | 0.4 (0.2–0.9) | |
Vomiting † | 26/87 (29.9) | 22/67 (32.8) | 1.1 (0.6–2.3) | |
Lethargy† | 19/87 (21.8) | 10/67 (14.9) | 0.6 (0.3–1.5) | |
Symptoms ≥3 d before admission | 58/158 (36.7) | 74/139 (53.2) | 2.0 (1.2–3.1) | |
Admission to intensive care unit | 1/159 (1.0) | 2/139 (1.4) | 2.3 (0.2–25.7) | |
Mechanical ventilation needed | 0/159 (0) | 1/139 (1.0) | Not calculated | |
Supplemental oxygen needed | 37/159 (23.3) | 61/139 (43.9) | 2.6 (1.6–4.2) | |
Antimicrobial drugs prescribed on admission | 151/158 (95.6) | 134/139 (96.4) | 1.2 (0.4–4.0) | |
Duration of hospitalization >2 d |
117/157 (74.5) |
107/138 (77.5) |
1.2 (0.7–2.0) |
|
No. deaths/no. patients (case-fatality ratio) | 2/158 (1.3) | 2/138 (1.5) | 1.1 (0.2–8.3) |
*Pos, positive; OR, odds ratio.
†Patients <5 y of age.
1This information has been presented at Options for the Control of Influenza VIII, Cape Town, South Africa, September 5–9, 2013.