Table 1.
Median Number of Close Contacts per Participant, Median Age of Close Contacts, and Median Number of Indoor Contacts per Participant, According to Baseline Demographic Data on 571 Randomly Selected Residents of a South African Township Community, 2010
| Category | Total No. in Sample | Close Contacts |
Median No. (IQR) of Indoor Contacts |
|||||||
| Total No. of Individuals Contacteda | Median No. (IQR) of Close Contacts |
Median Age (IQR) of All Close Contacts, years | ||||||||
| Type I (Physical) | Type II (Nonphysical) | Types I + II (All) | Type I (Physical) | Type II (Nonphysical) | Type III (Casual) | Types I + II + III (All) | ||||
| Total sample | 571 | 9,049 | 12 (7–18) | 9 (5–15) | 20 (13–29) | 21 (13–30) | 8 (5–13) | 6 (3–11) | 14 (0–32) | 30 (12–54) |
| Age group, years | ||||||||||
| 0–4 | 66 | 760 | 13 (9–17) | 5 (3–8) | 14 (10–22) | 23 (10–31) | 9 (7–14) | 3 (2–7) | 3 (0–24) | 16 (9–40) |
| 5–9 | 63 | 1,040 | 14 (9–20) | 10 (4–12.5) | 23 (16–32) | 10 (7–22) | 9 (5–13) | 6 (3–10) | 15 (1–29) | 32 (13–52) |
| 10–14 | 65 | 1,211 | 14 (10–22) | 13 (7–19) | 27 (18–39) | 14 (11–19) | 10 (6–13) | 8 (6–12) | 23 (4–40) | 43 (19–57) |
| 15–19 | 74 | 1,449 | 13 (8-21) | 14 (7-22) | 25.5 (18-38) | 18 (15-25) | 8 (6-13) | 8 (5-15) | 22 (4-35) | 40 (18-60) |
| 20–24 | 81 | 1,284 | 10 (6–16) | 10 (7–15.5) | 19 (12–29) | 24 (19–30) | 7 (4–13) | 8 (4–11) | 17 (0–35) | 33 (10–66) |
| 25–29 | 62 | 1,002 | 11 (7–17) | 9.5 (5.5–15.5) | 20.5 (13–27) | 27 (19–32) | 8 (4–13) | 6 (3–11) | 16.5 (0–47) | 32 (10–70) |
| 30–34 | 48 | 792 | 10.5 (8–18) | 8 (5–12) | 18.5 (12.5–27) | 28 (20–34) | 8 (6–12) | 5 (3–8) | 18.5 (0–37.5) | 31.5 (10.5–58) |
| 35–39 | 26 | 383 | 11.5 (9–18) | 6 (3–11.5) | 19 (12–26) | 29 (20–37) | 8 (5–12) | 4 (2–10) | 8 (0–29) | 20.5 (10–49) |
| 40–44 | 47 | 680 | 9 (5–18) | 9 (4–13) | 18 (12–27) | 30 (19–39) | 6.5 (4–14) | 5 (3–9) | 13 (0–29) | 25 (11–50) |
| ≥45 | 39 | 448 | 9 (4–13) | 9 (4–13) | 15 (10–21) | 29 (19–40) | 7.5 (4–11) | 7 (4–10) | 6 (0–25) | 18 (10–41) |
| P valueb | <0.001 | <0.001 | <0.001 | <0.001 | 0.11 | <0.001 | 0.01 | <0.001 | ||
| Gender | ||||||||||
| Female | 293 | 4,847 | 12 (8–19) | 10 (5–16) | 21 (14–32) | 19 (12–30) | 9 (6–13) | 7 (4–11) | 16 (0–33) | 32 (13–55) |
| Male | 278 | 4,202 | 11 (7–17) | 9 (5–13) | 19 (13–27) | 22 (14–32) | 7 (4–12) | 6 (3–9) | 13 (0–30) | 29 (10–53) |
| P value | 0.10 | 0.05 | 0.02 | <0.001 | 0.001 | 0.01 | 0.61 | 0.05 | ||
| Employment status | ||||||||||
| Unemployedc | 152 | 2,031 | 9 (5–14) | 9 (5–12) | 17 (11.5–22.5) | 26 (18–33) | 6 (4–10) | 6 (3–9) | 3 (0–20) | 16 (9–36.5) |
| Employed | 154 | 2,563 | 11 (7–18) | 9 (5–14) | 19.5 (13–29) | 28 (20–35) | 9 (5–14) | 6 (3–10) | 25 (3–45) | 39.5 (16–66) |
| P value | 0.002 | 0.38 | 0.001 | <0.001 | 0.001 | 0.77 | <0.001 | <0.001 | ||
| Level of schooling | ||||||||||
| Nonattendingd | 64 | 699 | 12 (8–15) | 4.5 (3–8) | 14 (10–19.5) | 24 (12–32) | 8 (6–10.5) | 3 (2–7) | 1.5 (0–7) | 12.5 (8–20) |
| Crèche | 16 | 223 | 16 (13–26) | 5 (4–7) | 22.5 (14.5–28.5) | 6 (3–28) | 12.5 (9.5–18) | 5 (4–7) | 25 (20–26.5) | 39.5 (34.5–47.5) |
| Primary school | 105 | 1,912 | 14 (10–20) | 11 (7–18) | 27 (17–37) | 12 (9–18) | 9 (5–13) | 8 (5–11) | 21 (2–35) | 37 (17–54) |
| Secondary school | 75 | 1,537 | 16.5 (10–24) | 12 (6–22) | 29 (20–38) | 17 (15–23) | 9 (6–16) | 8 (3.5–14) | 24 (5–40) | 46 (31–70) |
| Tertiary education | 5 | 84 | 12 (11–27) | 8 (6–12.5) | 26 (20–33) | 27 (20–35) | 11 (11–14) | 7.5 (6–12) | 59 (29–81) | 78 (55–92) |
| P value | 0.02 | <0.001 | <0.001 | <0.001 | 0.01 | 0.004 | <0.001 | <0.001 | ||
| Day of survey | ||||||||||
| Sunday | 66 | 1,038 | 12 (8–18) | 9 (5–14) | 22 (13–27) | 23 (15–32) | 8 (4.5–12) | 6 (4–10) | 5 (0–32) | 22.5 (9–56) |
| Monday | 56 | 961 | 13 (7–20) | 9.5 (3.5–20) | 23 (13–37) | 17 (12–28) | 9 (5–14) | 6 (2–13.5) | 23 (4.5–34) | 40 (22–56.5) |
| Tuesday | 75 | 1,189 | 12 (7–16) | 8 (5–14) | 19 (14–28) | 25 (15–32) | 8 (5–13) | 6 (3–11) | 14 (1–35) | 35 (12–56) |
| Wednesday | 135 | 2,182 | 13 (8–19) | 10 (5–16) | 21 (14–30) | 19 (11–30) | 9 (6–13) | 7 (4–11) | 15 (1–32) | 34 (13–53) |
| Thursday | 73 | 1,084 | 14 (9–19) | 10.5 (3–13) | 19 (12–29) | 21 (10–30) | 8 (6–13) | 6 (2–10) | 18 (0–30) | 30 (9–51) |
| Friday | 65 | 1,057 | 10 (7–18) | 11 (7–20) | 20 (13–33) | 20 (13–31) | 8 (6–14) | 8 (4–14.5) | 25 (6–39) | 42 (19–60) |
| Saturday | 101 | 1,538 | 11 (6–15) | 8 (4–12) | 18 (13–25) | 23 (14–32) | 7 (4–11) | 6 (3–9) | 4 (0–21) | 16 (9–45) |
| P value | 0.27 | 0.26 | 0.51 | <0.001 | 0.13 | 0.26 | 0.001 | 0.004 | ||
Abbreviation: IQR, interquartile range.
Close contacts met for the “first time today.”
P values (Kruskal-Wallis analysis of variance by ranks) indicate whether a significant difference between median numbers or ages of contacts exists across a given category (age group, gender, employment status, level of schooling, or day of survey).
Participants were regarded as unemployed if they were older than age 18 years and not employed.
Participants were regarded as school nonattendees if they were aged 18 years or younger and were not attending crèche, primary school, secondary school, or a tertiary educational institution.