TABLE 2.
Occurrence of Cryptosporidium oocysts and Giardia cysts in influent and effluent samples from Norwegian STW
| Sample type | Results fora:
|
|||
|---|---|---|---|---|
|
Cryptosporidium
|
Giardia
|
|||
| 50-μl native samples | 2-ml samples | 50-μl native samples | 2-ml samples | |
| Influent samples from 40 different STW across Norway | ||||
| No. (%) of STW positive | 16 (40) ac | 32 (80) ad | 22 (55) bc | 37 (93) bd |
| Range of oocyst/cyst numbers detected (extrapolated to per liter) | 4,000-24,000 | 100-1,100 | 4000-28,000 | 100-13,600 |
| Mean concnb (SD) (extrapolated to per liter) | 6,781 ei (5,935) | 242 ej (226) | 7,595 fi (6,676) | 1,903 fj (2,833) |
| Median concnb (extrapolated to per litre) | 4,000 | 200 | 4,000 | 800 |
| Effluent samples (n = 72) from 3 different STW | ||||
| No. (%) of positive samples | 29 (40) km | 44 (61) kn | 32 (44) lm | 53 (74) ln |
| Range of oocyst/cyst numbers detected (extrapolated to per liter) | 4,000-36,000 | 100-44,500 | 4,000-44,000 | 100-51,333 |
| Mean concnb (SD) (extrapolated to per liter) | 10,429 go (10,405) | 1,316 gp (6,675) | 12,387 ho (10,295) | 3,029 hp (7,708) |
| Median concnb (extrapolated to per liter) | 4,000 | 100 | 8,000 | 500 |
Numbers followed by the same lowercase letter have been compared statistically (Fisher's exact probability test or two-sided t test, as appropriate). The following list describes the significance obtained. a, P = 0.0005; b, P = 0.0003; c, P = 0.26 (no significant difference); d, P = 0.19 (no significant difference); e, P < 0.02; f, P< 0.03; g, P < 0.00003; h, P < 0.00001; i, P > 0.05 (no significant difference); j, P < 0.002; k, P = 0.0193; l, P = 0.0006; m, P = 0.736 (no significant difference); n, P= 0.155 (no significant difference); o, P > 0.05 (no significant difference); p, P > 0.05 (no significant difference).
Positive samples only.