2017 Annual Report for the Emerging Infections Program for Clostridioides difficile Infection

2017 Annual Report Print Version pdf icon[PDF – 2 pages]

In 2017, a total of 15,512 cases of C. difficile infection (CDI) were reported to the Emerging Infections Program (EIP) in 35 counties in 10 US states (California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee).

The overall distribution of EIP CDI cases and crude incidence by selected demographic factors and epidemiologic classification are presented in Table 1. Data in this report are not intended to be directly compared to annual reports from other years, and should not be used to determine annual changes in EIP CDI incidence rates because single year calculations do not account for changes in testing practices by reporting facilities.

Table 1. Reported Number of CDI Cases and Crude Incidence by Sex, Age Group, Race, and Epidemiologic Classification Among the 10 EIP Sitesa
Table 2 Ribotype and Isolates
Demographic Characteristic Population ≥1 Year of Age Community Associated CDIb
No.
Community Associated CDIb
Incidencec
Healthcare Associated CDIb
No.
Healthcare Associated CDIb
Incidencec
All
CDI
No.
All
CDI
Incidencec
Sex
Male 5,828,894 2829 48.53 3672 63.00 6501 111.53
Female 6,077,618 4710 77.49 4301 70.77 9011 148.27
Age group
1-17 years 2,538,020 601 23.68 206 8.12 807 31.80
18-44 years 4,649,874 1787 38.44 974 20.94 2761 59.38
45-49 years 821,951 461 56.14 321 39.00 782 95.14
50-54 years 799,021 548 73.06 471 58.98 1055 132.04
55-59 years 788,083 601 76.22 684 86.84 1285 163.05
60-64 years 690,026 676 97.99 823 119.25 1499 217.24
≥65 years 1,619,537 2829 174.69 4494 277.48 7323 452.17
Race
White 8,034,967 6135 76.35 5802 72.21 11937 148.56
Other 3,871,545 1404 36.27 2171 56.07 3575 92.35
Total 11,906,512 7539 63.32 7973 66.96 15512 130.28
  1. The epidemiologic classification was statistically imputed for 1.7% of the observed CDI cases, and race was statistically imputed for 15.3% of the observed CDI cases. The weighted frequency of cases in Colorado and Georgia was based on 33% random sampling for cases aged ≥18 years.
  2. A CDI case was classified as community-associated if the C. difficile-positive stool specimen was collected on an outpatient basis or within 3 days after hospital admission in a person with no documented overnight stay in a healthcare facility in the preceding 12 weeks. All CDI cases that do not meet the aforementioned criteria were classified as healthcare-associated.
  3. Cases per 100,000 persons.
Laboratory Characterization of C. difficile Isolates

In 2017, a total of 1050 C. difficile isolates were submitted to CDC for further analysis. The total number of isolates received from each site ranged from 11 to 285, with a median of 85.5. The majority of the isolates (98%) were collected in metropolitan areas.

Among all isolates submitted, 143 distinct ribotypes were detected. Ribotype 106 was the most common ribotype among community-associated C. difficile isolates, followed by 002, 020, and 027 (Table 2). Among healthcare-associated C. difficile isolates, ribotype 027 predominated, followed by 106, 002 and 014 (Table 3).

A decrease in ribotype 027 occurred from 9% in 2016 to 6% in 2017 among community-associated C. difficile isolates (p=0.07), whereas ribotype 027 remained relatively stable among healthcare-associated C. difficile isolates between 2016 (16%) and 2017 (15%). A significant overall decline in ribotype 027 has been observed since 2012 among both community-associated (17% vs. 6%; p<0.0001) and healthcare-associated (21% vs. 15%; p=0.02) isolates. Additionally, ribotype 076, which was observed in 8 EIP sites, increased from 2% in 2016 to 5% in 2017 (p=0.05) among healthcare-associated isolates and replaced ribotype 020 as one of the top 5 healthcareassociated isolates in 2017.

Twenty-three percent of the isolates harbored a deletion in tcdC. Twenty-two percent of the isolates were binary toxin-positive, and among these, ribotypes 027, 078, and 019 predominated.

Table 2. Frequency of Ribotypes Among Community-Associated C. difficile Isolates, 2017 (n=495)
Table 2 Community-Associated (n=495)
Ribotype No of isolates % isolates
106 60 12%
002 48 10%
020 32 6%
027 28 6%
014 26 5%
054 16 3%
076 15 3%
019 13 3%
015 12 2%
017 11 2%
078 11 2%
Others 223 45%
Table 3. Frequency of Ribotypes Among Healthcare-Associated C. difficile Isolates, 2017 (n=555)
Table 3 Healthcare-Associated (n=555)
Ribotype No of isolates % isolates
027 81 15%
106 54 10%
002 38 7%
014 37 7%
076 26 5%
020 24 4%
054 20 4%
015 19 3%
056 18 3%
078 15 3%
001_072 14 3%
Others 209 38%

Note: Data in this report were generated on March 27, 2019.