Contamination with hepatitis B virus DNA in gastrointestinal endoscope channels: risk of infection on reuse after on-site cleaning

Risk of parenterally transmitted hepatitis following exposure to invasive procedures in Italy: SEIEVA surveillance 2000-2021

BACKGROUND & AIMS

Surgical interventions and invasive diagnostic/therapeutic procedures are known routes of transmission of viral hepatitis. Using data from the Italian surveillance system for acute viral hepatitis (SEIEVA), the aim of this study was to investigate the association between specific types of invasive procedures and the risk of acute HBV and HCV infections.

METHODS

Data from SEIEVA (period 2000-2021) were used. The association between acute HBV and HCV infection and potential risk factors, i.e. surgical interventions and diagnostic/therapeutic procedures (given according to the ICD-9-CM classification), was investigated in comparison to age-matched hepatitis A cases, used as controls, by conditional multiple logistic regression analysis.

RESULTS

A total of 8,176 cases with acute HBV, 2,179 with acute HCV, and the respective age-matched controls with acute HAV infection were selected for the main analysis. Most of the procedures evaluated were associated with the risk of acquiring HBV or HCV. The strongest associations for HBV infection were: gynaecological surgery (odds ratio [OR] 5.19; 95% CI 1.12-24.05), otorhinolaryngological surgery (OR 3.78; 95% CI 1.76-8.09), and cardiac/thoracic surgery (OR 3.52; 95% CI 1.34-9.23); while for HCV infection, they were: neurosurgery (OR 11.88; 95% CI 2.40-58.85), otorhinolaryngological surgery (OR 11.54; 95% CI 2.55-52.24), and vascular surgery (OR 9.52; 95% CI 3.25-27.87). Hepatitis C was also strongly associated with ophthalmological surgery (OR 8.32; 95% CI 2.24-30.92). Biopsy and/or endoscopic procedures were significantly associated with both HCV (OR 3.84; 95% CI 2.47-5.95) and, to a lesser extent, HBV infection (OR 1.48; 95% CI 1.16-1.90).

CONCLUSIONS

Despite the progress made in recent years, invasive procedures still represent a significant risk factor for acquiring parenterally transmitted hepatitis viruses, thus explaining the still numerous and unexpected cases diagnosed among the elderly population in Italy. Our results underline the importance of observing universal precautions to control the iatrogenic transmission of hepatitis viruses.

IMPACT AND IMPLICATIONS

Cases of parenterally transmitted acute viral hepatitis in the elderly population, that are difficult to explain based on the most widely recognised risk factors, continue to be diagnosed in Italy. Based on the Italian SEIEVA surveillance of acute viral hepatitis data, this study highlights an increased risk of acquiring hepatitis B and C following exposure to invasive procedures, which might explain the observed cases in elderly individuals. Furthermore, this finding emphasises the need to observe universal precautions strictly, in healthcare settings, including in the case of minor surgical procedures.

Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

The bioburden (blood, protein, pathogens and biofilm) on flexible endoscopes after use is often high and its removal is essential to allow effective disinfection, especially in the case of peracetic acid-based disinfectants, which are easily inactivated by organic material. Cleaning processes using conventional cleaners remove a variable but often sufficient amount of the bioburden. Some formulations based on peracetic acid are recommended by manufacturers for the cleaning step. We performed a systematic literature search and reviewed the available evidence to clarify the suitability of peracetic acid-based formulations for cleaning flexible endoscopes. A total of 243 studies were evaluated. No studies have yet demonstrated that peracetic acid-based cleaners are as effective as conventional cleaners. Some peracetic acid-based formulations have demonstrated some biofilm-cleaning effects and no biofilm-fixation potential, while others have a limited cleaning effect and a clear biofilm-fixation potential. All published data demonstrated a limited blood cleaning effect and a substantial blood and nerve tissue fixation potential of peracetic acid. No evidence-based guidelines on reprocessing flexible endoscopes currently recommend using cleaners containing peracetic acid, but some guidelines clearly recommend not using them because of their fixation potential. Evidence from some outbreaks, especially those involving highly multidrug-resistant gram-negative pathogens, indicated that disinfection using peracetic acid may be insufficient if the preceding cleaning step is not performed adequately. Based on this review we conclude that peracetic acid-based formulations should not be used for cleaning flexible endoscopes.

Analysis of the air/water channels of gastrointestinal endoscopies as a risk factor for the transmission of microorganisms among patients

BACKGROUND

For the effective reprocessing of gastrointestinal endoscopes, contaminants must be removed from the entire surface. However, these devices have long and narrow channels that can make this process difficult.

METHODS

In this cross-sectional study, the staff assigned to reprocess gastroscopes and colonoscopes in 37 services located throughout Brazil completed a questionnaire regarding reprocessing practices geared toward the channels in these devices. In addition, samples from these air/water channels were collected for microbiological analysis.

RESULTS

Contamination was detected in 71.8% (28/39) of the samples obtained from the air/water channels of colonoscopes, and in 70% (42/60) of the samples from the air/water channels of gastroscopes. The median microbial load was 1,800 colony-forming units (CFU)/mL in the colonoscopes and 750 CFU/mL in the gastroscopes. The main microorganisms isolated from the air/water channels of gastroscopes were Pseudomonas aeruginosa (26.4%), Escherichia coli (18.9%), and Acinetobacter baumannii (9.4%), and those isolated from the colonoscopes included P aeruginosa (46.4%), A baumannii (14.3%), and Klebsiella pneumoniae (10.7%), among others. The possible causes of the contamination of these devices included the failure to fill these channels with cleaning solution, lack of friction during cleansing, and inadequate rinsing.

CONCLUSION

The contamination of the air/water channels did in fact represent a risk for the transmission of microorganisms during gastrointestinal endoscopy exams, possibly related to the inadequate reprocessing of these channels.

HBV and HCV serological markers in patients with the hepatosplenic form of mansonic schistosomiasis

CONTEXT

Blood transfusion is one of the major risk factors for the transmission of the hepatitis B (HBV) and C (HCV) viruses. However, there are no reports describing the endoscopic transmission of these viruses in patients with the hepatosplenic form of schistosomiasis.

OBJECTIVE

To estimate the prevalence of serological markers of HBV and HCV in patients with the hepatosplenic form of schistosomiasis and evaluate the possible risk factors associated with these infections.

METHODS

A cross-sectional study was conducted on 230 patients with hepatosplenic form of schistosomiasis who attended a university hospital in Recife, Northeastern Brazil, from February to August 2008. The patients answered a standardized questionnaire about risk factors. Serum samples were analyzed for anti-HBc total, anti-HBs, HBsAg, and anti-HCV using enzyme-linked immunosorbent assays. Univariate analysis and multiple logistic regression were performed.

RESULTS

The prevalence was 30% for anti-HBc total and/or HBsAg and 7.4% for anti-HCV. There was a higher frequency of the serological markers in females and in patients aged .50 years. A significant association was detected between the presence of anti-HCV and the receipt of six or more blood transfusions. There was no association of history and number of digestive endoscopies with the serological markers analyzed.

CONCLUSIONS

We observed a higher prevalence of serological markers for HBV and a lower prevalence of anti-HCV. Our results indicate that females and patients of an advanced age are the most affected categories and that patients that received multiple transfusions are at a higher probability of HCV infection.

Lumen claims of the STERRAD 100NX sterilizer: testing performance limits when processing equipment containing long, narrow lumens

BACKGROUND

According to manufacturers information, the STERRAD 100NX sterilizer-a low temperature H(2)O(2) gas plasma sterilizer-can adequately process single channel stainless steel lumens with an inside diameter of 0.7 mm or larger and a maximum length of 500 mm using standard cycle sterilizing conditions. The aim of this study was to qualify the performance of this H(2)O(2) gas plasma sterilizer under different experimental settings representing worst case conditions.

METHODS

Inoculated carriers were placed at the midpoint position of specified lumens and then submitted to flex scope sterilizing conditions. To simulate insufficient cleaning or crystalline residues, we added organic and inorganic challenges to our inoculated carriers.

RESULTS

For experiments done with unchallenged carriers, quantitative analysis reached a log(10) reduction rate of ≥5.71, whereas qualitative results showed no growth in 24 out of 30 biologic indicators tested using flex scope half cycle conditions. Any additional kind of challenge significantly impaired the sterilization outcome.

CONCLUSION

The findings of our current study emphasize the importance of a thorough validated cleaning of medical devices as well as timing for cleaning and decontamination before being exposed to the H(2)O(2) sterilization process and, furthermore, the need for strict adherence to manufacturer's recommendations.

Challenging the Sterrad 100NX sterilizer with different carrier materials and wrappings under experimental "clean" and "dirty" conditions

BACKGROUND

Sterrad sterilizers have been developed for the sterilization of thermolabile materials. The aim of the present study was to challenge the efficacy of this low-temperature hydrogen peroxide-based sterilization system with different carrier materials and wrappings under experimental "clean" and "dirty" conditions.

METHODS

We tested the sporocidal effect of the Sterrad 100NX sterilizer (Advanced Sterilization Products, Irvine, CA) on the carrier materials titanium, polyethylene, and polyurethane with single versus 3 wrappings of inoculated carriers. To simulate insufficient cleaning or crystalline residues, carriers were charged with spore inocula containing organic and inorganic burdens.

RESULTS

Our qualitative results show that irrespective of the number of wrappings in the "clean" condition, sterilization by the Sterrad 100NX was equally effective on all 3 carrier materials, reaching a log-10 reduction rate of ≥ 6 under standard half-cycle conditions. Any additional organic or inorganic challenge significantly impaired the sterilization outcome.

CONCLUSION

Results of our current study emphasize the utmost importance of thorough and reliable cleaning of medical devices before being exposed to a subsequent hydrogen peroxide sterilization process. Any institution using this sterilization technology should have a well-established and validated cleaning process and enforce a rigorous quality assurance program for all steps of the presterilization processing of medical devices.

Health care-associated transmission of hepatitis B and C viruses in endoscopy units

The risk for potential transmission of infectious agents during gastrointestinal (GI) endoscopy is concerning for patients and physicians. However, the instance of infection transmission remains rare after GI endoscopy procedures, with an estimated frequency of 1 in 1.8 million procedures. Endoscopy-related infection may occur when microorganisms are spread or transmitted from patient to patient by contaminated endoscopic or accessory equipments; from the GI tract through the bloodstream during endoscopy to susceptible organs or prostheses, or spread to adjacent tissues that are breached as a result of the endoscopy procedure; or from patients to endoscopy personnel and perhaps from endoscopy personnel to patients. Proper cleaning, disinfection, and reprocessing of endoscopies and accessories, and appropriate administration of intravenous drugs help to minimize the risk for infection transmission.

Patient to patient transmission of hepatitis B virus: a systematic review of reports on outbreaks between 1992 and 2007

BACKGROUND

Hepatitis B outbreaks in healthcare settings are still a serious public health concern in high-income countries. To elucidate the most frequent infection pathways and clinical settings involved, we performed a systematic review of hepatitis B virus outbreaks published between 1992 and 2007 within the EU and USA.

METHODS

The research was performed using two different databases: the PubMed Database and the Outbreak Database, the worldwide database for nosocomial outbreaks. Selection of papers was carried out using the Quorom algorithm, and to avoid selection biases, the inclusion criteria were established before the articles were identified.

RESULTS

Overall, 30 papers were analyzed, reporting on 33 hepatitis B virus outbreaks that involved 471 patients, with 16 fatal cases. Dialysis units accounted for 30.3% of outbreaks followed by medical wards (21.2%), nursing homes (21.2%), surgery wards (15.2), and outpatient clinics (12.1%). The transmission pathways were: multi-vial drugs (30.3%), non-disposable multi-patient capillary blood sampling devices (27.2%), transvenous endomyocardial biopsy procedures (9.1%), and multiple deficiencies in applying standard precautions (9.1%).

CONCLUSION

The analysis of transmission pathways showed that some breaches in infection control measures, such as administration of drugs using multi-vial compounds and capillary blood sampling, are the most frequent routes for patient-to-patient transmission of hepatitis B virus. Moreover some outbreak reports underlined that heart-transplant recipients are at risk of contracting hepatitis B virus infection during the transvenous endomyocardial biopsy procedure through indirect contact with infected blood as a result of environmental contamination. To prevent transmission, healthcare workers must adhere to standard precautions and follow fundamental infection control principles, such as the use of sterile, single-use, disposable needles and avoiding the use of multi-vial compounds in all healthcare settings including outpatient settings.

Hepatitis B virus prevalence and transmission risk factors in inflammatory bowel disease patients at Clementino Fraga Filho university hospital

AIM: To evaluate the prevalence of hepatitis B virus (HBV) infection in inflammatory bowel disease (IBD) patients that followed up in our hospital and try to identify the possible risk factors involved in this infection transmission.

METHODS: This was a cross-sectional study for which 176 patients were selected according to their arrival for the medical interview. All these patients had already IBD diagnosis. The patient was interviewed and a questionnaire was filled out.

RESULTS: In the group of 176 patients whom we examined, we found that 17% (30) were anti-HBc positive. Out of 30 patients with positive anti-HBc, 2.3% (4) had positive HBsAg and negative HBV-DNA. In an attempt to identify the possible HBV infection transmission risk factors in IBD patients, it was observed that 117 patients had been submitted to some kind of surgical procedure, but only 24 patients had positive anti-HBc (P = 0.085). It was also observed that surgery to treat IBD complications was not a risk factor for HBV infection transmission, since we did not get a statically significant P value. However, IBD patients that have been submitted to surgery to treat IBD complications received more blood transfusions then patients submitted to other surgical interventions (P = 0.015).

CONCLUSION: There was a high incidence of positive anti-HBc (17%) and positive HBsAg (2.3%) in IBD patient when compared with the overall population (7.9%).

Safety-cost trade-offs in medical device reuse: a Markov decision process model

Healthcare expenditures in the US are approaching 2 trillion dollars, and hospitals and other healthcare providers are under tremendous pressure to rein in costs. One cost-saving approach which is gaining popularity is the reuse of medical devices which were designed only for a single use. Device makers decry this practice as unsanitary and unsafe, but a growing number of third-party firms are willing to sterilize, refurbish, and/or remanufacture devices and resell them to hospitals at a fraction of the original price. Is this practice safe? Is reliance on single-use devices sustainable? A Markov decision process (MDP) model is formulated to study the trade-offs involved in these decisions. Several key parameters are examined: device costs, device failure probabilities, and failure penalty cost. For each of these parameters, expressions are developed which identify the indifference point between using new and reprocessed devices. The results can be used to inform the debate on the economic, ethical, legal, and environmental dimensions of this complex issue.