Table.
Seroprevalence according to sociodemographic characteristics
|
First survey |
Second survey |
p values for comparisons over time |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Positive tests | Adjusted for sampling design (estimate [95% CI]) | Adjusted for sampling design and test validity (estimate [95% CI]) | Positive tests | Adjusted for sampling design (estimate [95% CI]) | Adjusted for sampling design and test validity (estimate [95% CI]) | Unadjusted | Adjusted | ||
| Region | p<0·0001 | p<0·0001 | p<0·0001 | p<0·0001 | |||||
| Northeast | 46/6552 | 0·7% (0·5– 1·0) | 0·8% (0·5–1·1) | 273/9801 | 2·8% (2·4–3·2) | 3·2% (2·8–3·7) | p<0·001 | p<0·001 | |
| North | 272/5064 | 5·4% (4·7– 6·1) | 6·3% (5·4–7·2) | 419/5449 | 7·7% (6·9–8·5) | 9·0% (8·0–10·1) | p<0·001 | p<0·001 | |
| Centre-west | 0/2477 | 0% (0·0–0·1) | 0% | 13/3565 | 0·4% (0·2–0·6) | 0·4% (0·2–0·7) | * | * | |
| Southeast | 22/5833 | 0·4% (0·2–0·6) | 0·4% (0·2–0·7) | 45/7778 | 0·6% (0·4– 0·8) | 0·6% (0·4–0·9) | p=0·099 | p=0·177 | |
| South | 7/5069 | 0·1% (0·0– 0·4) | 0·1% (0·0–0·6) | 3/4569 | 0·1% (0·0– 0·2) | 0% (0·0– 0·3) | p=0·281 | p=0·476 | |
| Sex | p=0·16 | p=0·27 | p=0·095 | p=0·16 | |||||
| Female | 189/14464 | 1·3% (1·1–1·5) | 1·5% (1·2–1·8) | 461/18155 | 2·5% (2·3–2·8) | 2·9% (2·6–3·3) | p<0·001 | p<0·001 | |
| Male | 158/10531 | 1·5% (1·3–1·8) | 1·7% (1·4–2·0) | 292/13007 | 2·2% (2·0–2·5) | 2·6% (2·3–3·0) | p<0·001 | p<0·001 | |
| Age, years | p=0·22 | p=0·42 | p=0·0015 | p=0·0056 | |||||
| 0–4 | 6/432 | 1·4% (0·5– 3·0) | 1·6% (0·6–3·5) | 11/573 | 1·9% (1·0–3·4) | 2·2% (1·1–4·0) | p=0·520 | p=0·563 | |
| 5–9 | 8/681 | 1·2% (0·5–2·5) | 1·3% (0·5–2·9) | 16/983 | 1·6% (0·9–2·6) | 1·9% (1·0–3·1) | p=0·448 | p=0·522 | |
| 10–19 | 31/2287 | 1·4% (0·9–1·9) | 1·5% (1·0–2·2) | 52/2856 | 1·8 (1·4–2·4) | 2·1% (1·5–2·8) | p=0·190 | p=0·225 | |
| 20–29 | 55/3866 | 1·4% (1·1–1·9) | 1·6% (1·2–2·2) | 118/4761 | 2·5% (2·0–3·0) | 2·9% (2·3–3·5) | p<0·001 | p=0·002 | |
| 30–39 | 58/3834 | 1·5% (1·2–1·9) | 1·7% (1·3–2·3) | 122/4668 | 2·6% (2·2–3·1) | 3·0% (2·5–3·6) | p<0·001 | p=0·001 | |
| 40–49 | 63/3972 | 1·6 (1·2–2·0) | 1·8% (1·4–2·4) | 155/4885 | 3·2% (2·7–3·7) | 3·7% (3·1–4·4) | p<0·001 | p<0·001 | |
| 50–59 | 67/4016 | 1·7% (1·3– 2·1) | 1·9% (1·4– 2·5) | 133/5019 | 2·6% (2·2–3·1) | 3·1% (2·5–3·7) | p=0·002 | p=0·005 | |
| 60–69 | 33/3382 | 1·0% (0·7–1·4) | 1·1% (0·7–1·6) | 79/4264 | 1·9% (1·5–2·3) | 2·1% (1·7–2·7) | p=0·002 | p=0·005 | |
| 70–79 | 22/1797 | 1·2% (0·8–1·8) | 1·4% (0·8–2·1) | 49/2262 | 2·2% (1·6–2·9) | 2·5% (1·8–3·4) | p=0·025 | p=0·040 | |
| ≥80 | 4/728 | 0·5% (0·1–1·4%) | 0·6% (0·1–1·6) | 18/891 | 2·0% (1·2–3·2) | 2·3% (1·4–3·7) | p=0·018 | p=0·045 | |
| Ethnicity | p<0·0001 | p<0·0001 | p<0·0001 | p<0·0001 | |||||
| Amarelo (East Asian) | 8/685 | 1·2% (0·5–2·4) | 1·3% (0·5–2·8) | 15/827 | 1·8% (1·0–2·9) | 2·1% (1·1–3·5) | p=0·311 | p=0·392 | |
| Branco (White) | 61/9493 | 0·6% (0·5–0·8) | 0·7% (0·5–1·0) | 138/11011 | 1·3% (1·1–1·5) | 1·4% (1·2–1·7) | p<0·001 | p<0·001 | |
| Indígena (Indigenous) | 12/327 | 3·7% (1·9–6·4) | 4·2% (2·2–7·2) | 24/440 | 5·5% (3·6–7·9) | 6·3% (4·2–9·2) | p=0·251 | p=0·298 | |
| Pardo (Brown) | 229/11042 | 2·1% (1·8–2·4) | 2·4% (2·0–2·8) | 444/14282 | 3·1% (2·8–3·4) | 3·6% (3·2–4·0) | p<0·001 | p<0·001 | |
| Preto (Black) | 32/2961 | 1·1% (0·7–1·5) | 1·2% (0·8–1·8) | 114/3923 | 2·9% (2·4–3·5) | 3·4% (2·7–4·1) | p<0·001 | p<0·001 | |
| Household size | p<0·0001 | p<0·0001 | p=0·0003 | p=0·0023 | |||||
| 1 | 62/5074 | 1·2% (0·9–1·6) | 1·4% (1·0–1·8) | 150/5888 | 2·5% (2·1–3·0) | 3·0% (2·5–3·5) | p<0·001 | p<0·001 | |
| 2 | 79/7012 | 1·1% (0·9–1·4) | 1·3% (1·0–1·6) | 192/9148 | 2·1% (1·8–2·4) | 2·4% (2·0–2·8) | p<0·001 | p<0·001 | |
| 3 | 54/5429 | 1·0% (0·7–1·3) | 1·1% (0·8–1·5) | 153/6807 | 2·2% (1·9–2·6) | 2·6% (2·2–3·1) | p<0·001 | p<0·001 | |
| 4–5 | 102/5835 | 1·7% (1·4–2·1) | 2·0% (1·6–2·5) | 189/7483 | 2·5% (2·2–2·9) | 2·9% (2·5–3·4) | p=0·002 | p=0·006 | |
| ≥6 | 50/1645 | 3·0% (2·1–4·2 | 3·5% (2·5–4·9) | 69/1836 | 3·8% (3·0–4·7) | 4·4% (3·4–5·6) | p=0·245 | p=0·317 | |
| Wealth quintiles | p=0·0052 | p=0·012 | p<0·0001 | p<0·0001 | |||||
| Poorest | 101/5590 | 1·8% (1·5–2·2) | 2·1% (1·6–2·6) | 237/7369 | 3·2% (2·8–3·7) | 3·7% (3·2–4·3) | p<0·001 | p<0·001 | |
| 2nd | 73/4728 | 1·5% (1·2–2·0) | 1·8% (1·3–2·3) | 168/5774 | 2·9% (2·5–3·4 | 3·4% (2·9–4·0) | p<0·001 | p<0·001 | |
| 3rd | 63/4798 | 1·3% (1·0–1·7) | 1·5% (1·1–2·0) | 127/5950 | 2·1% (1·8–2·6) | 2·5% (2·0–3·0) | p=0·001 | p=0·005 | |
| 4th | 64/4852 | 1·3% (1·0–1·7) | 1·5% (1·1–1·9) | 127/5927 | 2·1% (1·8–2·6) | 2·5% (2·0–3·0) | p=0·001 | p=0·004 | |
| Richest | 46/5018 | 0·9% (0·7–1·2) | 1·0% (0·7–1·4) | 94/6142 | 1·5% (1·2–1·9) | 1·8% (1·4–2·2) | p=0·004 | p=0·009 | |
| Total | |||||||||
| Cities with ≥200 participants in both surveys | 333/20 084 | 1·7% (1·5–1·9) | 1·9% (1·7–2·2) | 551/20 414 | 2·7% (2·5–3·0) | 3·1% (2·8–3·4) | p<0·001 | p<0·001 | |
| All cities in each phase | 347/24 995 | 1·4% (1·2–1·6) | 1·6% (1·4–1·8) | 753/31 162 | 2·4% (2·2–2·6) | 2·8% (2·5–3·1) | p<0·001 | p<0·001 | |
Missing values represented 2·1% of the responses on ethnicity, and less than 0·1% for the remaining variables.
*
p values for trends over time could not be calculated because prevalence was equal to 0 in the first survey.