TABLE 4.

Cryptosporidium recoveries in samples seeded with viable and modified oocysts

Stream water siteStream flow conditionViable oocystsModified oocysts
Vol filtered (liters)Pellet vol (ml)Vol examined (liters)Adjusted oocyst recovery (%)aIMS positive controlsVol filtered (liters)Pellet vol (ml)Vol examined (liters)Adjusted oocyst recovery (%)a
Alabama 1Elevated8.30.38.317649.00.39.022
Alabama 2aElevated8.30.18.337778.50.18.559
Alabama 2bElevated7.00.57.02.0677.50.84.713
Colorado 1Effluent9.01.53.024829.51.04.812
Colorado 2Elevated8.50.38.520619.30.39.319
Georgia 1Base9.50.39.510618.50.38.59.1
Georgia 1High5.00.55.010675.00.55.013
Georgia 2High8.81.04.414679.00.59.03.1
IndianaElevated9.00.59.03250b9.30.59.329
IowaBase8.80.28.829768.80.28.822
IowaHigh9.81.04.92.0749.81.04.94.0
LouisianaBase8.80.18.861879.50.19.551
LouisianaElevated8.00.58.023769.00.59.020
NebraskaHigh3.00.72.12.8615.01.51.63.0
NebraskaBase9.50.59.542779.50.59.532
OhioElevated9.80.39.815619.80.39.825
OhioHigh9.80.59.840829.30.59.351
South Carolina 1Base9.80.19.849679.80.19.830
South Carolina 1Elevated100.310325810.50.310.528
South Carolina 2Elevated100.68.317589.80.68.121
TexasElevated7.50.84.718878.21.04.112
TexasBase9.50.49.525798.50.48.524
Virginia 1Base8.50.18.521778.50.18.512
Virginia 2Elevated9.00.29.034749.50.29.542
Washington 1aBase100.2102879100.21025
Washington 1bBase100.5102182100.51023
Washington 2High8.50.58.510677.80.57.815
Wisconsin 1High8.52.51.715619.52.51.920
Wisconsin 2Base9.00.95.027798.80.86.537
Wisconsin 2High7.00.57.038747.00.65.829
Avg8.40.57.323.871.88.60.67.723.6
  • a If pellet volume was greater than 0.5 ml, the entire sample volume was not examined. Oocyst recovery was adjusted for the pellet volume examined.

  • b Slide was dropped and cracked, so counts are underestimated; this value was not used in average and statistical analyses.