Table 2.
Effectiveness of decontamination onLegionellabacterial loading
| Month | Mean of load value (CFU/l) (post-decontamination period) | Mean of bacterial load in natural logarithmic numbers | t | p |
|---|---|---|---|---|
| October 2008 |
992.2414 |
6.9000 |
0.6591 |
0.2550 |
| November 2008 |
583.8235 |
6.3696 |
1.1843 |
0.1183 |
| December 2008 |
397.0000 |
5.9839 |
1.6083 |
0.0541 |
| January 2009 |
320.1613 |
5.7688 |
1.8698 |
0.0309 |
| February 2009 |
295.1282 |
5.6874 |
2.1259 |
0.0169 |
| March 2009 |
306.3265 |
5.7247 |
2.3673 |
0.0091 |
| April 2009 |
315.3801 |
5.7538 |
2.5402 |
0.0056 |
| May 2009 |
295.0256 |
5.6871 |
2.7428 |
0.0031 |
| June 2009 |
417.9909 |
6.0355 |
2.7060 |
0.0035 |
| July 2009 |
498.4615 |
6.2115 |
2.6624 |
0.0039 |
| August 2009 |
554.6850 |
6.3184 |
2.6735 |
0.0038 |
| September 2009 |
592.1561 |
6.3838 |
2.6817 |
0.0037 |
| October 2009 |
753.6237 |
6.6249 |
2.4677 |
0.0069 |
| November 2009 |
752.5163 |
6.6234 |
2.5500 |
0.0055 |
| December 2009 |
748.6751 |
6.6183 |
2.6023 |
0.0047 |
| January 2010 |
726.0479 |
6.5876 |
2.7144 |
0.0034 |
| February 2010 |
934.4538 |
6.8400 |
2.3195 |
0.0103 |
| March 2010 |
962.5000 |
6.8695 |
2.3432 |
0.0097 |
| April 2010 |
1369.3270 |
7.2221 |
1.3341 |
0.0912 |
| May 2010 |
1314.9530 |
7.1816 |
1.4680 |
0.0712 |
| June 2010 |
1521.4860 |
7.3274 |
1.0917 |
0.1376 |
| July 2010 |
1482.9550 |
7.3018 |
1.1885 |
0.1174 |
| August 2010 |
1707.7110 |
7.4429 |
0.7837 |
0.2167 |
| September 2010 |
1697.6230 |
7.4370 |
0.8044 |
0.2107 |
| October 2010 |
1684.2690 |
7.4291 |
0.8432 |
0.1996 |
| November 2010 |
1635.7890 |
7.3999 |
0.9556 |
0.1697 |
| December 2010 |
1719.8530 |
7.4500 |
0.8037 |
0.2109 |
| January 2011 | 1721.6250 | 7.4510 | 0.8141 | 0.2079 |
[In Table 2 are reported the results of the unpaired t-tests performed to compare the mean value of the bacterial load in the pre-decontamination period (grand mean: 2142.7840 CFU/L – 7.6698 in logarithmic value) with the ones of the post-decontamination period].