European Journal of Cardiovascular Medicine

Bloodstream infections (BSIs) are a significant cause of morbidity and mortality worldwide, particularly in hospitalized patients, leading to prolonged hospital stays, increased healthcare costs, and high mortality rates (1). Early and accurate detection of BSIs is critical for initiating appropriate antimicrobial therapy, reducing complications, and improving patient outcomes (2). Traditional blood culture methods remain the gold standard for diagnosing BSIs; however, these methods have limitations due to their long turnaround time, which typically ranges from 24 to 72 hours (3). This delay often results in the administration of broad-spectrum empirical antibiotics, increasing the risk of antimicrobial resistance and adverse drug reactions (4).

In recent years, rapid molecular diagnostic techniques (RMDTs) have emerged as an innovative approach for the early detection of bloodstream pathogens and antimicrobial resistance markers. These methods, including polymerase chain reaction (PCR)-based assays, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS), and next-generation sequencing (NGS), offer faster and more precise identification of causative organisms compared to conventional blood cultures (5,6). Studies have demonstrated that the use of RMDTs can significantly reduce the time to targeted antimicrobial therapy, optimize antimicrobial stewardship, and improve clinical outcomes in patients with sepsis and BSIs (7,8).

Despite their advantages, the clinical impact of RMDTs in routine hospital settings, particularly in general medicine wards, remains an area of ongoing research. While some studies report a significant reduction in mortality and length of hospital stay with RMDTs, others indicate that their effectiveness depends on various factors, including integration with antimicrobial stewardship programs and institutional protocols (9,10). Therefore, this study aims to evaluate the clinical outcomes of RMDTs compared to conventional diagnostic methods in general medicine wards, focusing on time to pathogen identification, duration of empirical antibiotic therapy, hospital stay, and mortality rates.

Study Design and Setting

This prospective, observational study was conducted in the general medicine wards of a tertiary care hospital over a period of six months. The study aimed to evaluate the impact of rapid molecular diagnostic techniques (RMDTs) compared to conventional blood culture methods in the early detection of bloodstream infections (BSIs).

Study Population

A total of 200 patients admitted with suspected bloodstream infections were included. Inclusion criteria comprised adult patients (≥18 years) presenting with clinical signs of sepsis, including fever, hypotension, tachycardia, and elevated inflammatory markers. Patients who had received antibiotic therapy for more than 48 hours before blood sample collection or those with incomplete medical records were excluded.

Sample Collection and Processing

For each patient, two sets of blood samples (each consisting of an aerobic and anaerobic bottle) were collected using aseptic techniques before initiating antibiotic therapy. One set was processed using conventional blood culture methods, while the other underwent testing with a rapid molecular diagnostic platform.

• Conventional Blood Culture: Blood samples were incubated in an automated blood culture system for up to five days. Positive cultures underwent Gram staining, subculturing, and biochemical testing for pathogen identification. Antibiotic susceptibility testing was performed using the disk diffusion method.
• Rapid Molecular Diagnostic Techniques: Blood samples were processed using a commercially available multiplex polymerase chain reaction (PCR)-based assay capable of detecting common bloodstream pathogens and antimicrobial resistance genes within six hours.

Outcome Measures

Primary outcomes included:

• Time to pathogen identification, measured from blood sample collection to confirmed identification.
• Duration of empirical antibiotic therapy, defined as the number of days the patient received broad-spectrum antibiotics before switching to targeted therapy.
• Length of hospital stay, recorded from admission to discharge.
• 28-day mortality rate, determined based on survival status within 28 days of hospital admission.

Secondary outcomes assessed the appropriateness of antimicrobial therapy adjustments following diagnostic results. The appropriateness of therapy was defined as the switch from empirical to targeted treatment based on microbial identification and susceptibility data.

Statistical Analysis

Data were analyzed using SPSS software. Descriptive statistics were used to summarize baseline patient characteristics. Continuous variables (e.g., time to pathogen identification, hospital stay) were compared using the Student’s t-test or Mann-Whitney U test, as appropriate. Categorical variables (e.g., mortality rates, therapy adjustments) were analyzed using the chi-square test. Kaplan-Meier survival analysis was performed to compare mortality outcomes between the two diagnostic methods. A p-value <0.05 was considered statistically significant.

Baseline Characteristics of Study Participants

A total of 200 patients were included in the study, with 100 patients in the rapid molecular diagnostic technique (RMDT) group and 100 in the conventional blood culture (CBC) group. The mean age of the participants was 57.4 ± 12.3 years, with 55% being male. There were no significant differences in baseline characteristics, including comorbidities such as diabetes mellitus, hypertension, and chronic kidney disease, between the two groups (p > 0.05) (Table 1).

Table 1. Baseline Characteristics of Study Participants

Time to Pathogen Identification

The mean time required for pathogen identification was significantly lower in the RMDT group (6.2 ± 2.1 hours) compared to the CBC group (47.6 ± 5.8 hours) (p < 0.001). Rapid identification facilitated earlier adjustments in antimicrobial therapy, improving targeted treatment outcomes (Table 2).

Duration of Empirical Antibiotic Therapy

Patients in the RMDT group received empirical antibiotics for a shorter duration (4.2 ± 1.1 days) compared to those in the CBC group (6.8 ± 1.5 days), with a statistically significant difference (p < 0.05) (Table 2).

Length of Hospital Stay

The mean hospital stay was significantly reduced in the RMDT group (9.5 ± 2.3 days) compared to the CBC group (12.7 ± 3.1 days) (p = 0.03) (Table 2).

Table 2. Comparison of Clinical Outcomes between RMDT and CBC Groups

28-Day Mortality Rate

The 28-day mortality rate was lower in the RMDT group (12%) than in the CBC group (18%), although the difference did not reach statistical significance (p = 0.08) (Table 2).

Appropriateness of Antimicrobial Therapy Adjustments

Appropriate antimicrobial therapy adjustments were made in 85% of cases in the RMDT group, compared to 62% in the CBC group (p < 0.05). The rapid availability of microbial identification and susceptibility results led to timely modifications in treatment regimens (Table 3).

Table 3. Appropriateness of Antimicrobial Therapy Adjustments

The findings indicate that the use of RMDTs significantly reduces the time to pathogen identification, leading to earlier targeted therapy and shorter hospital stays. While the reduction in mortality was not statistically significant, there was a notable trend favouring RMDTs for improved clinical outcomes.

The findings of this study demonstrate that rapid molecular diagnostic techniques (RMDTs) significantly reduce the time to pathogen identification in bloodstream infections (BSIs) compared to conventional blood culture methods, leading to earlier optimization of antimicrobial therapy. The integration of RMDTs in general medicine wards resulted in a shorter duration of empirical antibiotic use, reduced length of hospital stay, and a trend toward lower mortality rates. These results align with previous studies that highlight the advantages of RMDTs in improving clinical outcomes in patients with BSIs (1,2).

The reduction in time to pathogen identification in the RMDT group (6.2 ± 2.1 hours) compared to the conventional blood culture (CBC) group (47.6 ± 5.8 hours) is a significant finding. Traditional blood culture methods require prolonged incubation periods, followed by subculturing and susceptibility testing, delaying effective targeted therapy (3). Several studies have reported that RMDTs, particularly PCR-based assays, can provide accurate pathogen identification and antimicrobial resistance detection within hours, improving early clinical decision-making (4,5). A meta-analysis demonstrated that RMDTs could reduce diagnostic turnaround time by nearly 30–40 hours, supporting our findings (6).

Empirical antibiotic therapy was shorter in the RMDT group (4.2 ± 1.1 days) compared to the CBC group (6.8 ± 1.5 days). The early identification of pathogens and resistance markers allowed for rapid de-escalation or escalation of antimicrobial therapy, reducing unnecessary broad-spectrum antibiotic use. This is crucial in antimicrobial stewardship programs aimed at minimizing antimicrobial resistance and drug-related adverse effects (7,8). Previous research has also shown that RMDTs help in reducing unnecessary antibiotic exposure by enabling faster therapy modification based on microbial identification (9,10).

The length of hospital stay was significantly shorter in the RMDT group (9.5 ± 2.3 days) than in the CBC group (12.7 ± 3.1 days). Studies have suggested that faster pathogen identification and appropriate therapy adjustments contribute to improved clinical stability and earlier discharge, leading to reduced healthcare costs (11,12). A study on the implementation of RMDTs in sepsis management reported a mean reduction of hospital stay by approximately three days, which is consistent with our findings (13).

Although the 28-day mortality rate was lower in the RMDT group (12%) compared to the CBC group (18%), the difference did not reach statistical significance (p = 0.08). This could be attributed to the complexity of sepsis management, where factors such as host immune response, comorbidities, and organ dysfunction also play critical roles in patient outcomes (14). However, the observed trend suggests that RMDTs may have a potential mortality benefit, particularly in critically ill patients (15).

Overall, our findings support the integration of RMDTs into routine hospital workflows to enhance patient management and antimicrobial stewardship efforts. Future research should focus on large-scale, multicentre studies to further validate the impact of RMDTs on clinical and economic outcomes. Additionally, cost-effectiveness analyses should be conducted to assess the feasibility of broader implementation in resource-limited settings.

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