Long term outcomes of Hospital-Identified Clostridium Difficile Infection (HICDI): A retrospective cohort analysis of adult patients in a teaching hospital

Our aim is to present the importance of mobile Handheld Lung Ultrasound (HLUS) in COVID-19 patients at the bedside, which is a pre-screening tool with high diagnostic value that can provide triage of symptomatic patients at home (pre-hospital), emergency services, Intensive Care Units (ICU). In this context, the current role and importance of HLUS at the bedside in COVID-19 pneumonia has been summarized.

https://www.peertechzpublications.com/journals/global-journal-of-medical-and-clinical-case-reports Citation: Pandhem  Diffi cile (currently clostridioides) Infection (CDI) is a common cause of diarrhoea, particularly in patients who seek hospital treatment [1]. It is the commonest cause of nosocomial diarrhoea accounting for 15-25% of cases [2]. In the USA, it results in 500 000 infections and 29000 deaths annually [2,3]. It is also recognised as a major and increasing cause of diarrhoea in community settings [1,4]. found that Hospital-Acquired CDI (HA-CDI) was the most common cause of CDI infections contributing to 67% of all CDI diagnoses, with community-acquired CDI (CA-CDI) occurring at a rate of 26% [5]. Similar surveillance fi ndings have been documented in other countries [3,6,7].
There is increased 30-day mortality in patients with CDI compared to patients without CDI [8]. Increased mortality was associated with patients who were elderly, had multiple comorbidities or was admitted to the Intensive Care Unit [1,8,9]. There is also an increase in morbidity and health care costs with CDIs [10,11].
CDI can present acutely as a single episode or as a chronic illness with recurrences and relapses [12]. Short term outcomes have been extensively studied but little is known about long term outcomes [1,8,[11][12][13]. Two international single centre studies reported mortality outcomes of CDI at 6 months as 38% [14] and 34% [15]. Another international single centre study reported 2-year mortality as 32.5% [16]. No long term CDI outcomes have been studied in Australia. The present study primarily aims to review two-year term mortality of HICDI patients and its predictors.

Design and Study population
The study was conducted at The Canberra Hospital (TCH),

Results
As per ACTPAS, the total incidence of adult HICDI in TCH A total of 864 HICDI episodes were identifi ed during the 5-year study period. Figure 1 is the study consort chart highlighting the patients included and excluded in the study.
Four hundred and sixty-six ACT-resident patients accounting for 544 episodes of CDIs were included in the study. Of these, forty episodes of CDI were diagnosed in ICU/ HDU and the remaining episodes (n=504) were diagnosed in general wards.
In total, 409 patients had a single episode of CDI, 45 patients had two episodes of CDI diarrhoea and 12 patients had more than two episodes of CDIs.
The baseline demographic characteristics of the patients and their HICDI episodes are shown in Table 1. We noted a decrease in the number of HICDI episodes during years 2012-2016 as highlighted in Figure 2.  Various secondary outcomes are presented in Table 6 and the incidence of different types of HICDI per year in Figure 3.
Time to resolution: Factors predicting time to resolution of infection are reported in Table 7. Antibiotics usage prior to developing CDI signifi cantly delayed the time to resolution.
Compared to patients without antibiotic usage before developing CDI, patient with antibiotic usage took 70% longer time for resolution of infection.
Medications used for treating HICDI are given in Figure 4.
Usage of single-agent was common and no antibiotics were given in few HICDI episodes.

Primary outcome
This descriptive study documented the 2-year all-cause mortality of patients diagnosed with CDI in a tertiary hospital.
The in-hospital mortality of patients directly attributed to CDI was 3%.Unfortunately ,comparison of mortality in hospitalised patients without CDI was diffi cult given the baseline characteristics of these patients were very different to     those who had HICDI. In future, we suggest researchers to focus on subset of patients with similar baseline characteristics for example, haematological patients undergoing chemotherapy and compare patients who had HICDI infections to those who did not. This allows better comparison of long-term mortality outcomes.
By the end of the data collection, 53% of our cohort died due to multiple causes. The total two-year mortality was 33% for patients who had single episodes of CDI and 61.4% for patients with two or more CDIs. Previously, international single centre CDI studies have shown total 6-month mortality of 38% [14] and 34% [15] and 2-year mortality of 32.5% [16].
Our study adds to the information of these previously reported international studies [14][15][16].
Unlike our study, Young, et al. [16] included early CDI In our study, we noted that multiple factors were associated with long term mortality with the most signifi cant being the administration of chemotherapy, the presence of low albumin and admission to ICU. The predictors of mortality we studied have been found to be associated with short term mortality in several CDI studies [9,16,[18][19][20]. However, to validate their infl uence on long term mortality, large prospective studies are needed to better determine association and causation and to stratify HICDI patients.
The risk factors included in our study were also associated with a higher risk of mortality in several other CDI studies [1,18,[21][22][23]. In our cohort more than half of the patients were immunosuppressed or used PPI and a third had a gastrointestinal disease. Patients in this cohort also had additional recent or concurrent infective diagnoses necessitating antibiotic use (i.e. respiratory infection, neutropenic sepsis). All of these conditions themselves carry an inherent mortality and morbidity risk making the total mortality attributable to CDI diffi cult to determine in these populations.
In our observations, we found that CT scan was usually done to identify complications such as perforation, abdominal collections or to rule out other causes of abdominal pain.
Incidence of toxic megacolon was low and when confi rmed by CT scan in patients with underlying malignancy, usually resulted in a change of direction of care to palliation.

Secondary outcomes
Patients developed CDI within a few days of their hospital admission and diarrhoea usually lasted for almost a week. CDI infection was associated with increased length of hospital stay [2,13,14,24].
Mortality data was collected from a reliable source.

Limitations
There are several limitations in our study. It is a retrospective observational study and limited only to the ACT population. Because the non-ACT resident population that had CDI detected in the hospital was excluded, the results may be an underestimation for the whole hospital. Similarly, details of patients who died outside ACT (interstate or overseas) may not have been entered in the ACTPAS thus potentially leading to underestimation of HICDI long term mortality.
The current study did not compare mortality with an age and comorbidity matched control. We were unable to calculate the severity (Horn's index) [19] of CDI because tests required for calculation were not performed in every patient/episode. There is a possibility of measurement error, estimation bias and inaccurate data affecting our results. Some patients were sent home with symptoms of diarrhoea, so their length of hospital stay and time to resolution may also be subject to error.
Our fi ndings in single tertiary Australian hospital need to be confi rmed in a well-conducted prospective study involving multiple sites.

Conclusions
Our study found that patients diagnosed with HICDI had signifi cant long term mortality and morbidity. The two-year mortality increased with multiple CDI episodes. The most common cause of HICDI was HA-CDI. Usage of antibiotics before developing CDI increased the time to resolution. A large percentage of CDI patients were discharged before the resolution of diarrhoea and a small percentage of CDI patients were not treated. These fi ndings raise issues regarding infection control procedures and discharge process for CDI patients in hospital settings.