Monday, 28 February 2022

Material Transfer Into Aseptic Areas: Hierarchy Of Contamination Control


 

The presence of viable organisms and in particular bacterial spores in the Grade A environment presents a significant risk of contamination in aseptically prepared products and potential patient harm. In terms of risk terminology, the likelihood of product contamination is low, but the consequences are severe. This places a considerable emphasis upon transfer disinfection / decontamination. The method that was commonly used for this process was a standard transfer hatch (an interlocking device with no air supply) where items going in were (ideally) multi-wrapped and subject to manual disinfection (sometimes no more than ‘spray and pray,’ a slightly better process being the application of a sporicidal agent and wiping the surfaces of each item). This process has been improved by fitting localized air supplies (Grade A / ISO class 5 at rest), which is the minimum EU GMP Annex 1 requirement (as indicated in the 2020 draft)(3), and with the wider availability of decontamination chambers (which use bio-decontamination agents like hydrogen peroxide) (4). A commonality with each of these approaches is the application of a sporicide, with in aqueous or vapor form. The Technical Committee (CEN/TC 216 “Chemical disinfectants and antiseptics”) of the European Committee for Standardization has defined a sporicidal as a product which kills dormant bacterial spores of relevant test organisms under defined conditions.

However, despite some similarities there is a contamination control hierarchy with the different methods of transferring items into an aseptic area. If autoclaving is placed at the top (since it is a sterilization rather than a disinfection method), then it follows in order of increasing contamination risk:

 

  • ·         Autoclaving / depyrogenaton tunnels
  • ·         Automated cycle decontamination chambers.
  • ·         ‘Dynamic’ pass-through hatches with HEPA filtered air supply.
  • ·         ‘Static’ pass through chambers with no air supply.
  • ·         Personnel transferring items (e.g., via changing rooms).

This paper assesses the transfer disinfection process, the available technologies and critical bio-decontamination aspects, focusing on the important criteria for device assessment and operation.

Reference:

Sandle, T.(2021) Material Transfer Into Aseptic Areas: Hierarchy Of Contamination Control, Journal of GxP Compliance, 25 (5): https://www.ivtnetwork.com/article/material-transfer-aseptic-areas-hierarchy-contamination-control

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Thursday, 24 February 2022

Hepatitis E virus defies alcohol-based hand disinfectants

 



The hepatitis E virus (HEV) can cause serious liver inflammation and is the most common cause of acute virus-mediated hepatitis worldwide. Infection can be prevented through appropriate hygiene measures. Scientists have investigated the effectiveness of various common hand disinfectants against HEV. They were able to show that most formulations do not completely inactivate the virus.

 

In Germany and Europe, HEV has its natural reservoir in pigs. The infection can spread from animals to humans, which is called a zoonosis. This often happens through incompletely heated or raw meat products such as minced meat. In tropical regions of the world, infections occur via contaminated water, sometimes causing large outbreaks.

 

Together with the team of Professor Eike Steinmann, head of the Department of Molecular and Medical Virology at RUB, Behrendt has investigated whether common hand disinfectants can render the virus harmless. "We tested the effect of the alcohols ethanol and propanol, both individually and in the mixing ratios recommended by the WHO, and also commercial hand disinfectants," says Steinmann. "However, only one product that contained another component was effective."

 

Normally, HEV occurs non-enveloped and, like all non-enveloped viruses, is very resistant to chemical influences. However, virus particles circulating in the blood of patients are surrounded by a lipid envelope. "Not all disinfectants are effective against enveloped and non-enveloped viruses at the same time," says Steinmann. "We used both forms of HEV for our tests."

 

Although some of the disinfectants tested are certified to inactivate both enveloped and non-enveloped viruses, they were not sufficiently effective against HEV. "The alcoholic components dissolve the lipid envelope, but the resulting "naked" viruses are still infectious," says Behrendt. So HEV is literally hard to break down. The decisive advantage was a product that contains phosphoric acid as well as alcohol. This neutralised all the virus particles sufficiently.

 

Journal Reference:

 

Patrick Behrendt, Martina Friesland, Jan-Erik WiƟmann, et al. Hepatitis E virus is highly resistant to alcohol-based disinfectants. Journal of Hepatology, 2022; DOI: 10.1016/j.jhep.2022.01.006

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Wednesday, 23 February 2022

Investigating non-typhoidal Salmonella invasive disease



 

Researchers are calling for urgent investment in the prevention of a devastating emerging disease that kills tens of thousands of people each year. Researchers report on the frequency of a range of serious complications and very high risk for death among patients with found non-typhoidal Salmonella invasive disease. Non-typhoidal Salmonella invasive disease patients and the disease has a 15 per cent fatality ratio.

 

Non-typhoidal Salmonella invasive disease is an emerging neglected infectious disease that affects mainly young children and immunocompromised adults in sub-Saharan Africa. It affects more than half a million people a year and is fatal in 15 per cent of cases -- about 77,500 deaths worldwide annually.

 

The Vacc-iNTS Consortium is working on phase 1 trials of a candidate vaccine, but global support, funding and awareness are needed. The study refines the burden of the disease and justifies vaccine development efforts.

 

The Vacc-iNTS Consortium is a five-year project and has a NZ$11.8 million budget, funded by the European Union's Horizon 2020 Research and Innovation Programme.

 

Journal Reference:

 

Christian S Marchello, et al Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis. The Lancet Infectious Diseases, 2022; DOI: 10.1016/S1473-3099(21)00615-0


 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

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