Effectiveness of a Two-Step Testing Algorithm for Reliable and Cost-Effective Detection of Clostridium difficile Infection in a Tertiary Care Hospital in Saudi Arabia

Abstract

The aim of this study was to evaluate the effectiveness of a two-step algorithm for the detection of Clostridium difficile infection. Setting and Design: A two-step testing algorithm was evaluated for testing stool samples from patients suspected of Clostridium difficile infection (CDI). A total of 103 stool specimens were tested using the C. diff Quik Chek Complete enzyme immunoassay (EIA) test and the Xpert C. difficile PCR test. A two-step algorithm was implemented, and data from 3518 patient samples tested during a two-year period after implementation were analyzed to evaluate the effectiveness. The sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of the Quik Chek Complete EIA test were calculated using the Xpert C. difficile PCR test as a reference method. The sensitivity, specificity, PPV, and NPV of the Quik Chek Complete EIA test for C. difficile toxin were 46.7%, 100%, 100%, and 91%, respectively. The two-step algorithm, which combined the Quik Chek Complete EIA with Xpert C. difficile PCR, improved the sensitivity and also provided rapid detection. When algorithm-based testing was performed daily, there was a 66% reduction in turnaround time compared to batch testing using a lengthy ELISA procedure. Postimplementation data analysis showed that almost 89% of the samples could be reported immediately by initial screening with Quik Chek Complete EIA. Only 11% of the samples gave discrepant results and required PCR confirmation. According to our results, the two-step algorithm is an effective tool for the rapid and reliable detection of toxigenic C. difficile from stool samples.

Clostridioides difficile infections in Saudi Arabia: Where are we standing?

“… Study protocol CDIs' Incidence rate Location of study Reference Single-step Enzyme immunoassay testing (EIA) 2.4** in 2007 and 1.7** in 2008 Dhahran ( Al-Tawfiq and Abed, 2010 ); ( Aljafel et al, 2020 ); ( Alnimr et al, 2019 ) 8.4% Jeddah 0.03* Dammam Nucleic acid amplification tests (NAATs) 0.22* Dhahran ( Al-Tawfiq et al, 2020 ) ( Alnimr et al, 2019 ) 0.03* Dammam Two-step Nucleic acid amplification tests (NAATs) & culture in selective medium 13.7% Aljubail ( Shajan et al, 2014 ) Enzyme immunoassay testing (EIA) then confirmed by PCR testing such as GeneXpert multiplex PCR system. 5.54% Jeddah ( Qutub et al, 2019 ) ( Alzouby et al, 2020 ); ( Senok et al, 2017 ) 3.5** Riyadh 14.8% Riyadh Incidence rate (*per 1000 patients-day, **per 10,000 patients-day). …”

“…On the other hand, two recently published studies reported an 8.4% and 10% incidence from two tertiary hospitals, King Abdulaziz University-affiliated hospital in Jeddah and King Faisal specialist hospital in Riyadh, respectively ( Aljafel et al, 2020 , Qutub et al, 2019 ). Nevertheless, the study from Jeddah reported CDIs' results based on EIA testing only which has 88% sensitivity, without further confirmatory testing ( Aljafel et al, 2020 ).…”

“…Nevertheless, the study from Jeddah reported CDIs' results based on EIA testing only which has 88% sensitivity, without further confirmatory testing ( Aljafel et al, 2020 ). The other study, from Riyadh, utilized PCR as an affirmative step for specimens with discrepancy results after the initial immunoassay test, yet, the center is considered a specialist healthcare institution which limit their results’ external validity ( Qutub et al, 2019 ). Another study performed a six months surveillance at a Military hospital in Riyadh in 2015 which identified 106 episodes of CDIs by using EIA confirmed by PCR testing ( Table 1 ) ( Alzouby et al, 2020 ).…”

“…Epidemiological reports from the US, Canada, and Europe showed an incidence of 50 to 90 cases per 100,000 population between 2009 and 2011 ( Chitnis et al, 2013 ); however, the incidence trended up to a rate of 145 per 100,000 during 2017 ( Guh et al, 2020 ). There is no published study of CDI prevalence on a national level in Saudi Arabia, yet, the few published literature of single-center studies reported low rate of CDIs ( Aljafel et al, 2020 , Al-Tawfiq et al, 2020 , Qutub et al, 2019 ). One of these studies was able to detect an increasing trend of healthcare-associated CDIs from 17% in 2001 to 20% in 2018 out of all suspected diarrhea samples tested ( Al-Tawfiq et al, 2020 ).…”

Detection of Clostridium difficile Infection in Al-Quwayiyah General Hospital, Riyadh, Kingdom of Saudi Arabia

“…USA, Canada and Europe reported an incidence of 50 to 90 cases per 100,000 population between 2009 and 2011 [3]; which increased to 145 per 100,000 during 2017 [4]. In Saudi Arabia, there is a lack of epidemiological and surveillance studies and the exact incidence of CDIs and their complications, the low reporting incidence of CDIs attributed to the under-testing and underdiagnosing of CDIs due to either the shortage of supply of enzyme immunoassays and polymerase chain reaction (PCR) testing equipment in many healthcare facilities or the overutilization of anaerobic antibiotics [5][6][7].…”