. 2014 Jun 17;40(10):1429–1448. doi: 10.1007/s00134-014-3355-z

Table 1.

Description of the colonization index

Index	Definition	Formula
Colonization index (CI)	Ratio of the number of distinct non-blood body sites colonized by Candida spp. to the total number of body sites cultured. With the exception of blood cultures, samples collected from body sites other than those routinely screened are also considered. Only strains of Candida spp. with identical electrophoretic karyotypes are considered when calculating the CI	$CI = \frac{Number of sites colonized}{Number of sites cultured}$
Corrected colonization index (CCI)	Product of the CI and the ratio of the number of distinct body sites showing heavy growth (+++ from semi-quantitative culture or ≤10⁵ in urine or gastric juice) to the total number of body sites with Candida spp. heavy growth	$CCI = \frac{Number of sites colonized}{Number of sites cultured} \times \frac{Number of sites with heavy growth}{Total positive sites}$
Use of the CI^a	In patients perceived to be at risk of developing an invasive candidiasis: twice weekly surveillance culture of the following sites^b: - Oropharynx swab or tracheal secretions - Gastric fluid - Perinea swab or stool sample - Urine sample - Surgical wound swab or drained abdominal fluids - Catheter insertion sites

Index

Definition

Formula

Colonization index (CI)

Ratio of the number of distinct non-blood body sites colonized by Candida spp. to the total number of body sites cultured. With the exception of blood cultures, samples collected from body sites other than those routinely screened are also considered. Only strains of Candida spp. with identical electrophoretic karyotypes are considered when calculating the CI

CI = \frac{Number of sites colonized}{Number of sites cultured}

Corrected colonization index (CCI)

Product of the CI and the ratio of the number of distinct body sites showing heavy growth (+++ from semi-quantitative culture or ≤10⁵ in urine or gastric juice) to the total number of body sites with Candida spp. heavy growth

CCI = \frac{Number of sites colonized}{Number of sites cultured} \times \frac{Number of sites with heavy growth}{Total positive sites}

Use of the CI^a

In patients perceived to be at risk of developing an invasive candidiasis: twice weekly surveillance culture of the following sites^b:

- Oropharynx swab or tracheal secretions

- Gastric fluid

- Perinea swab or stool sample

- Urine sample

- Surgical wound swab or drained abdominal fluids

- Catheter insertion sites

^aIdentification of Candida species at the genetic level has only been performed in the original study. However, different species of Candida may contribute to the burden of fungi which will eventually result in symptomatic infection. Accordingly, we suggest to consider all species of Candida identified for the calculation of the CI

^bExcept for specific invasive candidiasis discussed in the section on pathophysiology of non-candidemic invasive candidiasis, Candida spp. isolated from these sites should be considered as colonization