Pathogen inactivation - defining ‘adequate’ bacterial protection

New strategies for the control of infectious and parasitic diseases in blood donors: the impact of pathogen inactivation methods

Around 70 infectious agents are possible threats for blood safety.

The risk for blood recipients is increasing because of new emergent agents like West Nile, Zika and Chikungunya viruses, or parasites such as Plasmodium and Trypanosoma cruzi in non-endemic regions, for instance.

Screening programmes of the donors are more and more implemented in several Countries, but these cannot prevent completely infections, especially when they are caused by new agents.

Pathogen inactivation (PI) methods might overcome the limits of the screening and different technologies have been set up in the last years.

This review aims to describe the most widely used methods focusing on their efficacy as well as on the preservation integrity of blood components.

Influence of platelet preparation techniques on in vitro storage quality after psoralen-based photochemical treatment using new processing sets for triple-dose units

BACKGROUND

The INTERCEPT Blood System (IBS) for platelets (PLTs) uses a combination of psoralen and ultraviolet-A light to inactivate pathogens that may contaminate PLT concentrates (PCs). However, no data are available on the quality of IBS-treated PLTs from different apheresis and buffy-coat PC preparation platforms using the new triple storage (TS) set.

STUDY DESIGN AND METHODS

The objective of this study was to evaluate the TS set on three different preparation platforms compared with the large-volume (LV) set, as control. PLT in vitro metabolic and activation parameters were studied over 7 days.

RESULTS

Several statistical differences are observed between the two sets, particularly for pH, oxygen pressure (pO₂ ), carbonic gaz pressure (pCO₂ ), and bicarbonate. The three different preparation techniques influence PLT parameters, and the difference is statistically significant for all the studied parameters, except for pCO₂ . The TS set has the advantage of shorter compound adsorption device time, higher PLT recoveries, and less PLT activation.

CONCLUSION

Results from the measured metabolic parameters and PLT variables obtained from PCs treated by LV and TS sets indicated good PLT function preservation up to 7 days of storage. The in vitro assessment results demonstrated acceptable PLT function for transfusion.

Pathogen inactivation: emerging indications

PURPOSE OF REVIEW

To review data about transfusion-transmitted infections so as to assess potential safety benefits of applying pathogen inactivation technology to platelets.

RECENT FINDINGS

Residual bacterial risk still exists. Multiple arbovirus epidemics continue to occur and challenge blood safety policy makers in nonendemic developed countries. There is new documentation of transfusion transmission of dengue and Ross River viruses, and new or increased concern about chikungunya and Zika viruses. Pathogen inactivation has been shown to inactivate almost all bacterial species and several epidemic arboviruses that pose a transfusion transmission risk. The two available platelet pathogen inactivation technologies show different levels of pathogen inactivation as measured by in-vitro infectivity assays; the clinical significance of this finding is not known.

SUMMARY

Pathogen inactivation can mitigate infectious risk and should do so more completely than other interventions such as donor questioning, donor/component recall, or donor testing. However, pathogen inactivation increases the cost of the pathogen-reduced blood component, which is a significant obstacle in the current healthcare environment. This may inhibit the ability to move forward with an effective new paradigm for blood safety that fulfills the implicit public trust in the blood system.