Modeling suggests that microliter volumes of contaminated blood caused an outbreak of hepatitis C during computerized tomography

Abstract

Background & aimsAcute hepatitis C (AHC) is not frequently identified because patients are usually asymptomatic, although may be recognized after iatrogenic exposures such as needle stick injuries, medical injection, and acupuncture. We describe an outbreak of AHC among 12 patients who received IV saline flush from a single multi-dose vial after intravenous contrast administration for a computerized tomography (CT) scan. The last patient to receive IV contrast with saline flush from a multi-dose vial at the clinic on the previous day was known to have chronic HCV genotype 1b (termed potential source, PS). Here we sought to confirm (via genetic analysis) the source of infection and to predict the minimal contaminating level of IV saline flush needed to transmit infectious virus to all patients.MethodsIn order to confirm the source of infection, we sequenced the HCV E1E2 region in 7 CT patients, in PS, and in 2 control samples from unrelated patients also infected with HCV genotype 1b. A transmission probabilistic model was developed to predict the contamination volume of blood that would have been sufficient to transmit infectious virus to all patients.ResultsViral sequencing showed close clustering of the cases with the PS. The transmission probabilistic model predicted that contamination of the multi-dose saline vial with 0.6–8.7 microliters of blood would have been sufficient to transmit infectious virus to all patients.ConclusionAnalysis of this unique cohort provides a new understanding of HCV transmission with respect to contaminating volumes and viral titers.

Modeling Challenges of Ebola Virus–Host Dynamics during Infection and Treatment

“…High concentration replicating virus was detected in semen during recovery [6]. At day 8 post-symptom onset in our patient, we observed a peak AST to ALT ratio of 3.5 compared with a ratio <1.0 in a cohort of patients with acute hepatitis C infection [8,9] (Figure 2), where viral replication and cellular injury are limited to the liver. We ran the model described by Madelain et al using the best estimated parameter space (reported in Table 1 in Madelain et al [4]) to gain further understanding of the suggested interplay among EBOV, the liver, and immune response.…”

“…Previously published serum and semen data are included for comparison [5,6]. Aspartate and alanine aminotransferase (AST/ALT) ratio kinetics during acute Ebola virus (n = 1) [5], or acute hepatitis C virus (n = 28) [8,9] infections. Pink shaded region represents first and third AST/ALT ratio quartiles.…”

Infection prevention and control in the medical imaging environment: a scoping review

“…(USA) 2 potential source patients and 5 newly infected patients • Evidence of HCV transmission among patients who had undergone myocardial perfusion imaging at the cardiology clinical on 2 separate dates • Transmission of HCV due to unsafe injection practices during myocardial perfusion imaging • Possibility that multi-patient use of vials occurred Chitnis et al, 2012 [ 23 ] To investigate an outbreak of bacterial meningitis at an outpatient radiology clinic, determine the source and implement measures to prevent additional infections Radiology clinic (USA) 35 cases of bacterial meningitis • Health care professional did not wear face mask; lapses in injection practice • Targeted education is needed among radiology health care professionals Kim et al, 2013 [ 24 ] To report on investigation and recommendations to control joint infections following arthrograms MRI, outpatient radiology centre (USA) 7 cases (5 confirmed, 2 probable) identified, underwent procedure during a 1-week period • No written procedures or documentation for infection control, aseptic-technique practices, medication preparation area cleaning/disinfection, staff training, or competency evaluations • Post-incident investigation observed that radiographers did not wash hands before preparation of injectable solutions; wore visibly soiled white coats, breaks in aseptic technique during preparation • Each vial of contrast media (labelled as ‘single dose’ by manufacturer), was re-entered with new syringes or needles multiple times for use on multiple patients Mansouri et al, 2015 [ 25 ] To describe multiyear experience in incident reporting related to MRI in large academic medical centre MRI, large academic medical centre. (USA) Infection control accounted for 0.4% of reported incidents • Examples of incidents: patient was on tuberculosis precautions and staff member interacting with patient was not informed; needle stick injury while disposing needle; respiratory therapist detached ventilator tubing from patient on precautions for Methicillin-resistant Staphylococcus aureus, and handed it to staff member, saliva and fluid splashed in staff member’s face Shteyer et al, 2019 [ 26 ] To describe an outbreak of AHC in 12 patients CT with contrast media. (Israel) 12 patients who received intravenous saline flush from a single multi-dose vial after intravenous contrast administration for a CT scan • Probability of intravenous saline flush event resulting in transmission of Hepatitis C • Modelling suggested that microl...…”

“…Sarvananthan et al reported that infection control was one of 14 incident type categories in a MID, accounting for only 1.35% of incidents [ 29 ]. The transmission of Hepatitis C was described in studies relating to contrast-enhanced CT procedures [ 22 , 26 – 28 ]. For example, in the study by Balmelli et al, breaches in safe injection practices were attributed to vial contamination, yet unsafe practices were not self-reported by staff who were interviewed [ 28 ].…”

New hope for hepatitis C virus: Summary of global epidemiologic changes and novel innovations over 20 years

“…HCV is a single-stranded RNA virus which is easily transmissible via microscopic amounts of as little as 0.6 microlitres of blood[ 18 ]. It is primarily transmitted through contaminated needles, inadequate sterilization of medical equipment, transfusion of unscreened blood, as well as high-risk sexual practices.…”