Table 1.
Climate variables and sero-prevalence of rickettsial and Q fever in the study areas.
| Regions surveyed | Average elevation (range) in metresa | Rainfall (cm)b | Max temp in °C (range)b | Min temp in °C (range)b | Humidity % (range)b | ST (%) | SF (%) | MT (%) | QF (%) |
|---|---|---|---|---|---|---|---|---|---|
| Jawadhi | 598 (500–773) | 99 | 34.1 (30–39) | 24.3 (21–27) | 71 (61–82) | 14.6 | 20.5 | 0 | 1 |
| Palamathi | 285 (230–413) | 99 | 34.1 (30–39) | 24.3 (21–27) | 71 (61–82) | 12.3 | 6.8 | 0 | 0.7 |
| Kalrayan | 795 (673–982) | 100 | 29.8 (26.2–34) | 20.4 (16.8–23.1) | 64 (45–75) | 16 | 29.9 | 2.4 | 11.5 |
| Nilgiris | 2046 (1933–2229) | 151 | 21 (19.7–23.4) | 13.2 (10.6–15) | 75 (57–85) | 2 | 5.2 | 2 | 4.3 |
| Salem | 251 (153–309) | 70 | 35.1 (30–39) | 24.2 (21–27) | 66 (57–79) | 10.5 | 1.7 | 0.6 | 11.6 |
| Vellore | 217 (206–246) | 94 | 32.4 (27.2–37.4) | 22.2 (16.9–26.2) | 63 (52–77) | 21 | 5.2 | 2.4 | 6.7 |
| Tiruvannamalai | 180 (147–216) | 81 | 32.9 (27.9–37.4) | 22.9 (18–26.5) | 63 (53–76) | 26.4 | 8.2 | 13.4 | 1.7 |
| Erode | 207 (157–275) | 80 | 32.8 (29.1–37.4) | 22.8 (19.9–25.7) | 61 (42–72) | 2.2 | 0 | 2.2 | 6.7 |
aOf the areas where sero-surveillance was conducted in this study.
bData for 2017 (Jan–Dec).