**Background:** During the COVID-19 pandemic, hospitalized patients with SARS-CoV-2 infection were recognized as potentially prone to both thromboembolic complications and hospital-acquired infections. Peripherally inserted central catheters (PICCs) and midline catheters (MCs) are ultrasound-guided venous access devices that have been associated with minimizing infectious complications in various patient populations. However, the incidence of catheter-related bloodstream infections (CRBSI) in COVID-19 patients remained unclear, with retrospective studies yielding controversial results. This study aimed to prospectively assess the incidence of catheter-related complications—particularly CRBSI—in a cohort of COVID-19 patients receiving PICCs or MCs.
**Methods:** This single-center, prospective observational study was conducted at a university hospital in Italy from October 2020 to May 2021. All consecutively admitted non-ICU patients with a clinical-laboratory diagnosis of SARS-CoV-2 infection who required a PICC or MC were enrolled. The primary endpoint was the incidence of PICC-related and MC-related bloodstream infections; secondary endpoints included other catheter-related complications. Devices were inserted and managed according to GAVeCeLT (Italian Group of Long-Term Venous Access) insertion and maintenance bundles, which include pre-procedural ultrasound, hand hygiene, skin antisepsis with 2% chlorhexidine, maximal barrier precautions, ultrasound-guided venipuncture, tip position verification (intracavitary ECG for PICCs, real-time ultrasound for MCs), subcutaneous anchorage, cyanoacrylate glue sealing, and transparent semipermeable membrane coverage. CRBSI was diagnosed using the differential time to positivity method (catheter blood culture positive at least 2 hours earlier than peripheral blood culture). Symptomatic catheter-related thrombosis (CRT) was confirmed by ultrasound. Statistical analysis used Stata/IC 16.0; continuous variables were compared using Student's t-test or Wilcoxon rank-sum test as appropriate, with P ≤ .05 considered significant. No a priori sample size calculation was performed.
**Key Results:** A total of 227 COVID-19 patients were enrolled (69 received PICCs, 158 received MCs). Mean age was 78.08 ± 13.49 years; 58.1% were female. Common comorbidities included hypertension (53.3%), cardiovascular disease (61.6%), previous lung disease (23.3%), diabetes (20.7%), and BMI >30 (22.4%). Total catheter days were 2,752 (889 PICC days, 1,863 MC days). The cumulative incidence of CRBSI was 4.35% (10 cases), corresponding to 3.5 episodes per 1,000 catheter days. Four CRBSI occurred in PICC patients (5.8%; 4.5/1,000 catheter days) and 6 in MC patients (3.8%; 3.2/1,000 catheter days). The mean time to CRBSI onset was similar between groups: 13.17 ± 8.35 days for PICCs and 14.25 ± 3.59 days for MCs. Staphylococcus aureus caused 50% of infections, followed by Candida parapsilosis (30%), Candida glabrata (10%), and Candida albicans (10%). Notably, 5 of 10 CRBSI occurred in patients with BMI >30 (2 PICC-related, 3 MC-related), representing a 4-fold higher incidence in obese patients (9.8% vs 2.79%). Noninfective complications were minimal: 11 dislodgements (4.84%; 5 self-inflicted, 6 accidental by staff), 2 cases of symptomatic CRT (0.9%, both in MCs), and no irreversible lumen occlusions or insertion-related complications.
**Clinical Implications:** This study demonstrates that COVID-19 patients in non-ICU settings have a higher incidence of CRBSI compared to general populations, with rates of 3.5/1,000 catheter days. Importantly, MCs showed infection rates similar to PICCs (3.2 vs 4.5/1,000 catheter days), challenging the common assumption that MCs carry lower infection risk. The early onset of infection (approximately 2 weeks) contrasts with longer times reported in non-COVID populations. The very low CRT rate (0.9%) is notable given COVID-19-associated thrombophilia, possibly mitigated by systematic antithrombotic prophylaxis. The higher infection risk may be explained by patient-related factors (older age, mean 78 years; high comorbidity burden; obesity) and pandemic-related factors (reduced patient access for device surveillance due to infection control precautions, and rapid turnover of less experienced nursing staff). These findings suggest that COVID-19 patients require heightened vigilance for catheter-related infections regardless of device type, and that strict adherence to insertion and maintenance bundles remains critical. Study limitations include single-center design, exclusion of ICU patients and other catheter types (CICCs, FICCs), and lack of formal compliance monitoring for maintenance bundles.