Dengue viremia in blood donors identified by RNA and detection of dengue transfusion transmission during the 2007 dengue outbreak in Puerto Rico

Evaluation of assays for nucleic acid testing for the prevention of chikungunya and dengue virus transmission by blood transfusion

BACKGROUND

The large dengue (DENV) and chikungunya (CHIKV) outbreaks observed during the last decade across the world, as well as local transmissions in non-endemic areas are a growing concern for blood safety. The aim of this study was to evaluate and compare the sensitivity of nucleic acid tests (NAT) detecting DENV and CHIKV RNA.

MATERIALS AND METHODS

Using DENV 1 to 4 International Standards, the limits of detection (LODs) calculated by probit analysis of two NAT assays; the cobas CHIKV/DENV assay (Roche Diagnostics) and the Procleix Dengue Virus Assay (Grifols) were compared. In addition, CHIKV-RNA LOD of the cobas CHIKV/DENV assay was evaluated.

RESULTS

For dengue, the 95% LOD of the cobas assay ranged between 4.10 [CI95%: 2.70-8.19] IU/mL (DENV-2) and 7.07 [CI95%: 4.34-14.89] IU/mL (DENV-4), and between 2.19 [CI95%: 1.53-3.83] IU/mL (DENV-3) and 5.84 [CI95%: 3.84-10.77] IU/mL (DENV-1) for Procleix assay. The Procleix assay had a significant lower LOD for DENV-3 (2.19 vs. 5.89 IU/mL) when compared to the cobas assay (p = 0.005). The 95% LOD for CHIKV-RNA detection of the cobas assay was 4.76 [CI95%: 3.08-8.94] IU/mL.

DISCUSSION

The two NAT assays developed for blood donor screening evaluated in this study demonstrated high and similar analytical performance. Subject to an appropriate risk-benefit assessment, they can be used to support blood safety during outbreaks in endemic areas or in non-endemic areas as an alternative to deferring blood donors during local transmission likely to affect the blood supply. The development of multiplex assays is expected to optimize laboratory organization.

Haemovigilance survey and screening strategy for arthropod-borne viruses in blood donors from Argentina

Arthropod-borne viruses (arboviruses) count among emerging infections, which represent a major challenge for transfusion safety worldwide. To assess the risk of arboviruses-transmission by transfusion (ATT), we performed a survey to evaluate the potential threat for transfusion safety. Samples were retrospectively and randomly collected from donors who donated during the peak of dengue incidence in Cordoba (years: 2016 and 2019-2022). A cost-efficient strategy for molecular screening was implemented with a nucleic acid test (NAT) configured with Flavivirus and Alphavirus-universal degenerated primers targeting conserved gene regions. Besides, we evaluated the neutralizing antibody (NAb) prevalence by plaque reduction neutralization test (PRNT). A total of 1438 samples were collected. Among the NAT-screened samples, one resulted positive for Flavivirus detection. Subsequent sequencing of the PCR product revealed Saint Louis Encephalitis Virus (SLEV) infection (GeneBank accession number OR236721). NAb prevalence was 2.95% for anti-Dengue, 9.94% anti-SLEV, 1.09% anti-West Nile Virus, and 0% anti-Chikungunya. One of the NAb-positive samples also resulted positive for IgM against SLEV but negative by ARN detection. This is the first haemovigilance study developed in Argentina that evaluates the potential risk of ATT and the first research to determine the prevalence of NAb against Flavivirus through PNRT to avoid possible cross-reactions between Ab against Flavivirus. Herein, the finding of one SLEV-viremic donor and the detection of anti-SLEV IgM in a different donor demonstrated a potential threat for transfusion safety and emphasized the need for increased vigilance and proactive measures to ensure the safety of blood supplies.

Flying under the radar - impact and factors influencing asymptomatic DENV infections

The clinical outcome of DENV and other Flaviviruses infections represents a spectrum of severity that ranges from mild manifestations to severe disease, which can ultimately lead to death. Nonetheless, most of these infections result in an asymptomatic outcome that may play an important role in the persistent circulation of these viruses. Also, although little is known about the mechanisms that lead to these asymptomatic infections, they are likely the result of a complex interplay between viral and host factors. Specific characteristics of the infecting viral strain, such as its replicating efficiency, coupled with host factors, like gene expression of key molecules involved in the immune response or in the protection against disease, are among crucial factors to study. This review revisits recent data on factors that may contribute to the asymptomatic outcome of the world's widespread DENV, highlighting the importance of silent infections in the transmission of this pathogen and the immune status of the host.

Arboviral Risk Associated with Solid Organ and Hematopoietic Stem Cell Grafts: The Prophylactic Answers Proposed by the French High Council of Public Health in a National Context

Diseases caused by arboviruses are on the increase worldwide. In addition to arthropod bites, most arboviruses can be transmitted via accessory routes. Products of human origin (labile blood products, solid organs, hematopoietic stem cells, tissues) present a risk of contamination for the recipient if the donation is made when the donor is viremic. Mainland France and its overseas territories are exposed to a complex array of imported and endemic arboviruses, which differ according to their respective location. This narrative review describes the risks of acquiring certain arboviral diseases from human products, mainly solid organs and hematopoietic stem cells, in the French context. The main risks considered in this study are infections by West Nile virus, dengue virus, and tick-borne encephalitis virus. The ancillary risks represented by Usutu virus infection, chikungunya, and Zika are also addressed more briefly. For each disease, the guidelines issued by the French High Council of Public Health, which is responsible for mitigating the risks associated with products of human origin and for supporting public health policy decisions, are briefly outlined. This review highlights the need for a "One Health" approach and to standardize recommendations at the international level in areas with the same viral epidemiology.

Prevalence of Dengue, Chikungunya and Zika Viruses in Blood Donors in the State of Pará, Northern Brazil: 2018-2020

Arboviruses have been reported over the years as constant threats to blood transfusion recipients, given the high occurrence of asymptomatic cases and the fact that the presence of viremia precedes the onset of symptoms, making it possible that infected blood from donors act as a source of dissemination. This work aims to identify the prevalence of dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection in blood donors during epidemic and non-epidemic periods; classify the donor as symptomatic or asymptomatic; and verify the need to include DENV, CHIKV and ZIKV in the nucleic acid test (NAT) platform in northern Brazil. We investigated 36,133 thousand donations in two years of collection in Northern Brazil. One donor was positive for DENV and one for CHIKV (0.002% prevalence). As the prevalence for arboviruses was low in this study, it would not justify the individual screening of samples from donors in a blood bank. Thus, DENV- and CHIKV-positive samples were simulated in different amounts of sample pools, and both were safely detected by molecular biology even in a pool of 14 samples, which would meet the need to include these three viruses in the routine of blood centers in endemic countries such as Brazil.

A Risk Assessment Model for Transfusion Transmission of Dengue

Dengue virus (DENV) is a disease-causing agent normally transmitted from person to person through the bite of an infected mosquito. In addition to mosquito-borne cases of dengue, there are instances of transmission of dengue after receipt of blood products or donor organs or tissue. To improve blood safety, we developed a quantitative risk assessment model to estimate the dengue risk of transmission to blood transfusion recipients from preclinical and subclinical blood donors. We derived predictive coefficients from model simulations for predicting the risk outcomes such as monthly infectious blood units and transfusion-transmitted DENV cases based on the rate of reported clinical cases. The model was validated with a previous study where donor blood samples from the 2012 dengue transmission season in Rio de Janeiro, Brazil were tested for DENV RNA by a transcription-mediated amplification (TMA) assay. In that study about 69.4% donations were tested by the TMA assay and 78 samples were found positive, indicating that 112 DENV RNA-positive donations would have been detected if testing screening had been performed on all donations. Our model estimated a mean of 93 (2.5^th%ile -97.5^th%ile : 47 - 186) infected units among the donations, which was consistent with the reported numbers.

Screening for Arboviruses in Healthy Blood Donors: Experience from Karachi, Pakistan (Jul-Dec 2018)

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DENV, WNV and JEV status was investigated in healthy blood donors at the Aga Khan University July to December 2018.

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ELISA for IgM antibodies and RT-PCR for viral RNA detection were performed.

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IgM antibodies for DENV and WNV were positive in 3.9% and JEV in 0.28% of the blood donors.

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Blood donors aged 19 and 30 years and residents of urban areas, of Karachi City were most frequent.

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DENV and WNV seropositivity were significantly associated with residence in Malir District of Karachi.

Mitigating the risk of transfusion-transmitted infections with vector-borne agents solely by means of pathogen reduction

Background

This study evaluated whether pathogen reduction technology (PRT) in plasma and platelets using amotosalen/ultraviolet A light (A/UVA) or in red blood cells using amustaline/glutathione (S‐303/GSH) may be used as the sole mitigation strategy preventing transfusion‐transmitted West Nile (WNV), dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viral, and Babesia microti, Trypanosoma cruzi, and Plasmodium parasitic infections.

Methods

Antibody (Ab) status and pathogen loads (copies/mL) were obtained for donations from US blood donors testing nucleic acid (NAT)‐positive for WNV, DENV, ZIKV, CHIKV, and B. microti. Infectivity titers derived from pathogen loads were compared to published PRT log₁₀ reduction factors (LRF); LRFs were also reviewed for Plasmodium and T. cruzi. The potential positive impact on donor retention following removal of deferrals from required questioning and testing for WNV, Babesia, Plasmodium, and T. cruzi was estimated for American Red Cross (ARC) donors.

Results

A/UVA and S‐303/GSH reduced infectivity to levels in accordance with those recognized by FDA as suitable to replace testing for all agents evaluated. If PRT replaced deferrals resulting from health history questions and/or NAT for WNV, Babesia, Plasmodium, and T. cruzi, 27,758 ARC donors could be retained allowing approximately 50,000 additional donations/year based on 1.79 donations/donor for calendar year 2019 (extrapolated to an estimated 125,000 additional donations nationally).

Conclusion

Pathogen loads in donations from US blood donors demonstrated that robust PRT may provide an opportunity to replace deferrals associated with donor questioning and NAT for vector‐borne agents allowing for significant donor retention and likely increased blood availability.

Effects of Acute Dengue Infection on Sperm and Virus Clearance in Body Fluids of Men

We investigated the effects of dengue virus (DENV) on semen using samples collected 7, 15, 30, 60, and 90 days after symptom onset from 10 infected volunteers on Réunion Island. We assessed characteristics of semen and reproductive hormones and isolated motile spermatozoa from semen. We assayed semen for DENV using reverse transcription PCR and searched for DENV RNA by virus isolation in Vero E6 cell cultures. Four volunteers had >1 DENV RNA-positive semen samples; 2 volunteers had DENV RNA–positive semen at day 15 and 1 at day 30. No motile sperm were DENV positive. After exposure to positive semen, few Vero E6 cells stained positive for DENV antigens, indicating low levels of replicative virus. We found DENV had shorter duration in semen than in blood. These findings support the possibilities that DENV is sexually transmissible for a short period after acute dengue illness and that acute dengue induces reversible alterations in sperm.

Chikungunya and Mayaro infective viruses in components of blood

OBJECTIVE

Evaluate the infectivity of Alphavirus Chikungunya and Mayaro in blood products in plaque forming units (UFP/ml).

BACKGROUND

Arboviruses are responsible for sporadic diseases or epidemics which cause serious public health issues. Due to the high number of asymptomatic infections and high viremia, blood donors may pass on these viruses by transfusion.

METHODS/MATERIALS

This study used blood bags that would be discarded after evaluation and certification of the absence of infections. The blood products obtained by centrifuging a unit of whole blood were called blood components. All blood bags were infected with viable viruses (previously quantified) compatible with Chikungunya and Mayaro viremia.

RESULTS

Blood bags inoculated with both Chikungunya and Mayaro viruses were able to keep infective viruses during the processing of blood products (red blood cell concentrate, platelet concentrate and fresh frozen plasma) and also after the recommended storage for each component, which may infect individuals transfused with those.

CONCLUSION

The results indicate that in order to prevent infections by Mayaro and Chikungunya viruses in blood products it is necessary to stimulate the development and use of diagnostic tests for these pathogens in donated blood.

Dengue seropositivity among blood donors in a tertiary hospital in Kerala, Southern India

Aim:

The aim of this study was to screen blood donors in a tertiary hospital in Kerala for dengue during the period of peak dengue transmission.

Materials and Methods:

One hundred and seventy-eight continuous serum samples obtained from asymptomatic blood donors during the monsoon season were subjected to ELISA for Dengue NS1 antigen and dengue immunoglobulin M (IgM) antibodies.

Results:

Dengue IgM antibodies were positive in 20 (11.23%) donors and NS1 antigen was positive in 1 (0.56%) donor. The presence of these markers in asymptomatic blood donors showed that they may have had active or subclinical dengue infection at the time of donation or in the recent past. The presence of NS1 in particular raises the possibility that the donor may have been viremic at the time of donation.

Conclusion:

The findings of this study suggest the risk of transfusion transmission of dengue during the monsoon in Kerala and strengthen the case for dengue screening among blood donors during this period of high incidence.

[Gestion of arboviral alerts: Experience feedback from the Secproch working group of the French "Haut Conseil de la santé publique" (2019-2021)]

The Secproch working group (for "sécurité des produits issus du corps humain") was created in 2019 within the « Haut Conseil de la santé publique » (HCSP) for addressing all the questions related to labile blood products, organs, tissues, cells (OTC) and gametes issued from human body. It is notably in charge of the management of alerts regarding arbovirus infections. These infections due to arthropod-transmitted viruses are responsible for emergence and reemergence, notably in the context of global warming. This review relates the alerts taken into consideration by the Secproch group between 2019 and 2021 following three pathologies due to Flaviviridae : dengue, West Nile virus (WNV) infection and tick-borne encephalitis (TBE). The dengue alerts have occurred in French Indies where the virus is endemic/epidemic, Reunion Island where the population was naïve until 2018 towards the virus, and the metropole where foci of autochthonous cases are observed sporadically. The WNV infection was responsible of both human and equine cases in 2019 in the South of France but with intensity much less than in 2018. At last, the TBE virus was at the origin of a cluster of about 40 cases in the Ain department following a contamination by crude non-pasteurized goat cheese. This review offers the opportunity to reevaluate the risks linked to these three viruses through blood products and organs/tissues/cells and to precise the means recommended by HCSP to secure these products.

Transfusion-transmissible dengue infections

Dengue is an important global health problem and is endemic in many developing and developed countries. Transmission of dengue may occur in several ways and information on transfusion-transmitted dengue is limited. We conducted a literature search on transfusion-related dengue using the PubMed, Scopus, Embase and Google Scholar databases and have summarized the findings. A number of apparently healthy blood donors have been found to be infected with the dengue virus (DENV) and thus may transmit the virus onto recipients of this blood. It is not possible to identify and exclude such donors at the donor selection stage and thus reliable screening tests should be available in highly endemic areas to ensure a safe blood supply.

Dengue RNA detection and seroprevalence in blood donors during an outbreak in the São Paulo State, Brazil, 2016

Most dengue virus (DENV) infections remain asymptomatic. This increases the risk of DENV transfusion transmission (TT-DENV) during outbreaks. We evaluated DENV viremia in 8475 blood donations assembled in minipools for the presence of DENV RNA. The tested samples were obtained between February and May, 2016, during a large DENV outbreak in Ribeirão Preto city, northeast region of the São Paulo State, Brazil. The DENV RNA + samples were serotyped and screened for DENV NS1. We also tested a significant number of plasma samples (n = 372) to estimate the DENV seroprevalence among blood donors in the region. We detected three DENV RNA + samples in the tested blood donations (n = 3/8475, 0.04%). From these, two samples were further serotyped as DENV-1 and one sample as DENV-2. All DENV RNA positive samples were negative for anti-DENV IgG, indicating the presence of primary acute infection. Moreover, two of the DENV RNA + samples were also NS1 antigen positive (antigenemia). The anti-DENV IgG seroprevalence among blood donor population was 50.8% (n = 189/372). Our results are in accordance with the presence of DENV primary infection in blood donors which can lead to transfusion transmission of the infection to recipients. Measures to exclude such donors should be adopted to prevent TT-DENV.

Detection of dengue, chikungunya, and Zika RNA in blood donors from Southeast Asia

BACKGROUND

Chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses are of concern due to the potential of transfusion transmission in blood, especially in regions such as Southeast Asia where the viruses are endemic. The recent availability of nucleic acid testing (NAT) to screen blood donations on an automated platform provides the opportunity to detect potentially infectious units in asymptomatic donors.

STUDY DESIGN AND METHODS

Three thousand blood donations from Vietnam and 6000 from Thailand were screened with a real-time polymerase chain reaction (PCR) test (cobas CHIKV/DENV, Roche Diagnostics, Indianapolis, IN) and equal numbers on cobas Zika (Roche Diagnostics). Reactive samples were tested by alternative NAT with resolution of discordant results by heminested PCR. Throughput of simultaneous testing of the two assays on the cobas 8800 system (Roche Diagnostics) was evaluated.

RESULTS

In Vietnam, 9 of 3045 samples were reactive for DENV and all were confirmed, for a prevalence (with 95% confidence interval [CI]) of 0.296% (0.135-0.560). In Thailand, 2 of 6000 samples were reactive for CHIKV, 4 of 6000 for DENV, and 1 of 6005 for ZIKV, and all confirmed. The prevalence of CHIKV is 0.033% (0.004-0.120), DENV 0.067% (0.018-0.171), and ZIKV 0.017% (0.000-0.093). The overall specificity for the cobas CHIKV/DENV and cobas Zika tests was 100% (99.959-100). For the simultaneous assay testing, 960 test results were available in 7 hours and 53 minutes.

CONCLUSION

Detection of CHIKV, DENV, and ZIKV RNA in donor samples in Vietnam and Thailand indicate the presence of the virus in asymptomatic blood donors. The cobas 6800/8800 systems (Roche Molecular Systems, Pleasanton, CA) enable screening blood donations in endemic areas for these viruses together or separately.

Use of Animal Models in Studying Roles of Antibodies and Their Secretion Cells in Dengue Vaccine Development

The cardinal feature of adaptive immunity is its ability to form memory responses that can be rapidly recalled to contain pathogens upon reencountering. Conferring a robust memory immune response to an infection is a key feature for a successful vaccination program. The plasmablasts are cells that not only can secret non-neutralizing antibodies but also can secrete the specific antibodies essential to neutralize and inactivate the invading pathogens. Dengue has been recognized as one of the most important vector-borne human viral diseases globally. Currently, supportive care with vigilant monitoring is the standard practice since there is as yet no approved therapeutic modality to treat dengue. Even though the approved vaccine has become available, its low efficacy with the potential to cause harm is the major hurdle to promote the widespread usage of the vaccine. Despite the decades of research on dengue, the major challenge in dengue vaccine development is the absence of suitable experimental animal models that reflect the pathological features and clinical symptoms, as seen in humans. Dengue is transmitted by the bite of mosquitoes carrying infectious dengue virus (DENV), which has four distinct serotypes. Recently, cases resulting from unconventional transmission routes, such as blood transfusion, organs as well as stem cells and bone marrow transplantations, and mother-to-infant vertical transmission, have been reported, suggesting an alternate route of DENV transmission exists in nature. This review discusses issues and challenges needing to be resolved to develop an effective dengue vaccine. Development of a robust and reliable dengue animal model that can reflect not only dynamic human clinical symptoms but also can answer around why preexisting neutralizing antibodies do not confer protection upon re-infection and immune protection marker for dengue vaccine efficacy evaluation.

Viral metagenomics in blood donations with post-donation illness reports from Brazil

BACKGROUND

Post-donation illness can be described as appearance of clinical symptoms in blood donors after donation. The consequent call back of the donor to report these symptoms to the blood collection institution is considered a post-donation illness report (PDIR). The most suitable way to examine whether PDIR is related to infection is to apply next-generation sequencing (NGS) and viral metagenomics. Investigation into a PDIR can reveal its importance for transfusion safety and help elaborate strategies for donor education in order to prevent the transfusion transmission of infections which are not routinely tested by the blood collection services.

MATERIALS AND METHODS

We applied NGS and viral metagenomics on blood donations which were deferred due to a PDIR. Thirty-three PDIR donations obtained in the Blood Center of Ribeirão Preto, Southeast Brazil, were evaluated. Sequencing was performed using Illumina NextSeq 550 (Illumina Inc, San Diego, CA, USA) equipment and the reads obtained for each sample were analysed by specific bioinformatic pipeline for the classification and discovery of emerging viruses. The identified viral agents by metagenomics were directly confirmed by molecular methods.

RESULTS

In all PDIR donations, we found abundant reads of commensal viruses belonging to the Anelloviridae family as well as human pegivirus-1. However, we were also able to identify blood donations positive for clinically important viruses like dengue serotype-2 (DENV-2) of the Asian-American genotype and parvovirus B19 (B19V). Both viruses were also confirmed by real-time polymerase chain reaction, detecting DENV-2 RNA in a significant number of cases (7 samples, 21.2%), compared to B19V which was confirmed in 1 case (3.0%).

DISCUSSION

Our study applies for the first time viral metagenomics to evaluate the significance of PDIRs. We confirm the crucial importance of the donor providing a timely PDIR for the prevention of transfusion transmission of viral infections which are not routinely tested in the blood banks worldwide.

Dengue virus serological markers among potential blood donors: an evidence of asymptomatic dengue virus transmission in Cameroon

Introduction

the risk of dengue virus or its antibodies which can be transmitted through blood transfusion by asymptomatic individuals infected, has been a major concern all over the world. Dengue is an endemic disease in sub-Saharan Africa, particularly in Cameroon. The purpose of this study is to determine the frequency of dengue virus (DENV) infection among potential blood donors at Yaounde Jamot Hospital.

Methods

serum samples were collected from 310 potential adult blood donors aged 18-57 years, who signed a written informed consent and completed the questionnaire between March 2019 and August 2019. This serum is used to screen for the presence of serological markers of DENV infection (NS1, IgM and IgG) using immunochromatographic tests (Zhuhai Encode Medical Engineering Co., Ltd, China). IgM/IgG positive samples were confirmed by enzyme-linked immunosorbent assays (ELISA).

Results

the overall prevalence was 24.8% among potential blood donors were subdivided as follows: 4.5% (14/310), 12.3% (38/310) and 6.1% (19/310) showed mono-positivity to DENV-NS1 antigen, anti-DENV IgM and anti-DENV IgG antibodies respectively. 1.9% (6/310) of potential blood donors showed dual positivity to anti-DENV IgM antibodies and anti-DENV IgG antibodies. The presence of DENV-NS1 antigen show asymptomatic viremia of dengue at the time of donation, while the presence of IgG antibodies reflects the high endemicity of dengue disease in the city of Yaoundé.

Conclusion

these findings demonstrate the high level of risk of the DENV transmission among potential blood donors to needy recipients, underscoring the importance of establishing dengue fever blood screening in different services and blood collection units in Cameroon to improve safety transfusion and control the dissemination of the DENV.

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.

Seroprevalence and factors associated with IgG anti-DENV positivity in blood donors in Burkina Faso during the 2016 dengue outbreak and implications for blood supply

OBJECTIVES

Our study aimed to update the seroprevalence and factors associated with anti-dengue virus (DENV) antibody positivity among blood donors and to discuss their implications for blood supply.

BACKGROUND

Questions on the potential transmission of DENV by transfusion increased after the documentation of the risk of transmission of the West Nile virus. This risk was estimated after transfusion of DENV RNA-positive blood units of up to 37.5%. In Burkina Faso, very few studies on DENV in blood donors have been conducted. As a result, there were no reliable data on DENV to allow the implementation of appropriate measures to control the risk of transmission of the dengue virus by blood transfusion.

METHODS

We conducted a 4-week cross-sectional study from December 4 to 30, 2016. Blood donors of both genders, aged 18-60 years, accepted for blood donation after medical selection were consecutively enrolled.

RESULTS

Our study included a total of 1007 blood donors, in which donors living in urban areas represented 78.2%. The mean age was 26.1 ± 8.1 years. After adjustment in a multiple regression logistic model, the odds of having IgG anti-DENV increased as age increased. The odds of DENV was 53% lower in rural areas (OR = 0.47; P = .000) compared to urban settings and 42% lower in mobile sites (OR = 0.58; P = .03) compared to fixed ones.

CONCLUSION

Our study provides new and useful insights for future research on the risk of TT-DENV throughout blood transfusion.

Clinical and laboratorial profiles of dengue virus infection in kidney transplant recipients: Report of a single center

Dengue infection (DI) is the most important arboviral infection in the world. The majority of immunocompetent patients will have asymptomatic or mild infections, but the degree of dengue severity in kidney transplant recipients (KTx) is unknown. In this study, we report the clinical profile and outcomes of 39 dengue cases in KTx. From a total of 1,186 KTx outpatients in follow-up we reviewed clinical and laboratory records of 60 (5%) patients admitted with suspected DI initially screened by NS-1, IgM, and when possible, multiplex nested PCR. The prevalence of DI in KTx was 3% (39/1,118), with symptoms leading to hospital admission being fever, myalgia, malaise, and headache. Laboratory tests showed leucopenia, thrombocytopenia, and liver enzyme elevation. DI was confirmed by positivity of NS-1 (33%), IgM (69%), and/or RT-PCR (59%). Twenty-three patients (59%) had dengue with warning signs, and 15% had severe dengue, 2 of them with a fatal course. Acute graft dysfunction occurred in 59% (mean nadir serum creatinine: 2.9 ± 2.6mg/dL), 4 of them requiring dialysis. CMV coinfection diagnosed in 19% of the cases and patients was associated with worse clinical presentation. Our results suggest that KTx with DI presented initial physical and laboratorial profile similar to the general population. However, DI in KTx seems to have a higher risk for graft dysfunction, severe dengue, and death. Because CMV coinfection aggravates the DI clinical presentation and recovery, it must be evaluated in all cases.

Zika Virus and the Safety of Blood Supply in Brazil: A Retrospective Epidemiological Evaluation

The potential for transfusion transmission of dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) has raised concerns about the safety of the blood supply in endemic areas. In this study, nucleic acid testing (NAT) for ZIKV, DENV, and CHIKV RNA was performed in asymptomatic blood donor samples in the city of Campinas, located in the southeast region of Brazil (1962 in 2015 and 1775 in 2016). The prevalence of reactive NAT was 0.15% in 2015 and 0.62% in 2016 for dengue, 0.05% in 2015 and 0.17% in 2016 for Zika, and 0% in both years for chikungunya. These results demonstrate the weakness of the clinical interview in screening these blood donors. Furthermore, positivity for ZIKV was detected in March 2015, 1 year before the first reported cases in the region. These data attest the feasibility of using donor samples held in library as a tool for retrospective epidemiological evaluation, which is particularly interesting considering emerging pathogens, for which data on their spread and penetrance are initially scarce.

Prevalence of Zika virus in blood donations: a systematic review and meta-analysis

BACKGROUND

Transfusion-Transmitted Zika virus (TT-ZIKV) has become an emerging threat to world blood banks due to the fast spread of ZIKV epidemics and high rate of asymptomatic infections. For the risk assessment of ZIKV infection in blood products, relevant studies in blood donations or blood donors tested for ZIKV were collected and analyzed systematically. The overall prevalence of ZIKV infection were estimated through meta-analysis and potential risk factors were detected. The results will provide important clues for the protocol design of blood screening tests.

METHODS

Relevant articles about the rate of ZIKV detected in blood samples were identified from PubMed, Scopus and Web Of Science using key terms search strategy until October 7, 2017. Eligible articles were screened following inclusion and exclusion criteria. Meta-analysis and subgroup analyses were performed by software R3.4.1. Overall postdonation and posttransfusion follow-ups were analyzed.

RESULTS

Ten literatures (528,947 blood samples) were included for meta-analysis. The overall pooled prevalence of ZIKV (RNA and antibody) in blood donations was 1.02% (95%CI 0.36-1.99). The pooled prevalence of ZIKV RNA in blood donations was 0.85% (95%CI 0.21-1.88) less than the pooled prevalence of anti-ZIKV antibodies 1.61% (95%CI 0.03-5.21), however the difference was not statistically significant (p = 0.52). The prevalence varied significantly in different geographical regions (p < 0.001). Blood donations were more than two times likely to be infected by ZIKV in Zika epidemic period (1.37, 95%CI 0.91-1.91) than in non-epidemic period (0.61, 95%CI 0-2.55). The prevalence of anti-ZIKV antibodies (1.61, 95%CI 0.03-5.21) was almost twice as much as ZIKV nucleic acid detected in blood donations (0.85, 95%CI 0.21-1.88). However, statistically significant differences were not observed. A total of 122 ZIKV positive blood donors were followed, of which 48 (39%) reported symptoms postdonation, but none of the 13 followed recipients reported any clinical symptoms related to Zika infection posttransfusion.

CONCLUSION

The pooled prevalence of Zika infection in blood donations was 1.02%. The prevalence varied greatly and reached to high-risk level in most of the situations. The results suggest that nucleic acid tests (NAT) for blood screening and pathogen reduction/inactivation technology (PRT) should be implemented in Zika-endemic areas and appropriate strategies should be designed according to different conditions. More studies are needed in the future to provide more evidence.

Identification and characterization of permissive cells to dengue virus infection in human hematopoietic stem and progenitor cells

BACKGROUND

Dengue virus (DENV) is a significant threat to public health in tropical and subtropical regions, where the frequency of human migration is increasing. Transmission of DENV from donors to recipients after hematopoietic stem cell transplantation has been steadily described. However, the underlying mechanisms remain unclear.

STUDY DESIGN AND METHODS

Freshly isolated bone marrow (BM) was subjected to DENV infection, followed by multicolor fluorescence-activated cell sorting (FACS) analysis. Virus in supernatants was collected and analyzed by plaque assay.

RESULTS

DENV-1 to DENV-4 could effectively infect freshly obtained BM and produced infectious virus. DENV infection did not change the quantitative population of hematopoietic stem and progenitor cells (HSPCs), megakaryocytic progenitor cells (MkPs) and megakaryocytes. Additionally, DENV antigen, nonstructural protein 1, was enriched in HSPCs and MkPs of DENV infected marrow cells. CD34+, CD133+, or CD61+ cells sorted out from BM were not only the major contributing targets facilitating the DENV infection directly but also facilitated the spread of DENV into other cells when cocultured.

CONCLUSION

Results suggest that DENV can efficiently infect HSPCs, which might jeopardize the recipients if DENV-infected cells were subsequently used. We therefore raise the need for DENV screening for both the donors and recipients of hematopoietic stem cell transplantation, especially for donors exposed to endemic areas, to mitigate DENV infection in immunocompromised recipients.

Dengue virus transmission from live donor liver graft

Arboviral transmission through transplanted organs is rare. We report a highly probable case of dengue viral transmission during live donor liver transplantation. Fever with severe thrombocytopenia was observed in the donor and recipient within 6 and 9 days after transplantation, respectively. Dengue diagnosis was confirmed by testing blood and explant tissue from the donor and recipient using dengue-specific NAT (nucleic acid testing) and serology. Serology indicated the donor had secondary dengue infection that ran a mild course. However, the dengue illness in the recipient was severe and deteriorated rapidly, eventually proving fatal. The recipient's explant liver tissue tested negative for viral RNA indicative of a pretransplant naïve status. The prM-Envelope gene sequence analysis of the donor and recipient viral RNA identified a similar serotype (DENV1) with almost 100% sequence identity in the envelope region. Molecular phylogenetic analysis of donor and recipient viral envelope sequences with regional and local dengue strains further confirmed their molecular similarity, suggesting a probable donor-to-recipient transmission via organ transplantation. Screening of living donors for dengue virus may be considered in endemic regions.

Emergent Arboviruses and Renal Transplantation: A Global Challenge

In recent years, Zika, Chikungunya, Dengue, West Nile Fever, and Yellow Fever epidemics have generated some concerns. Besides difficulties related to vector control, there are challenges related to behavior of pathologies not yet fully understood. The transplanted population requires additional care due to immunosuppressive drugs. Furthermore, the potential risk of transmission during donation is another source of uncertainty and generates debate among nephrologists in transplant centers. Do the clinical outcomes and prognoses of these infections tend to be more aggressive in this population? Is there a risk of viral transmission via kidney donation? In this review article, we address these issues and discuss the relationship between arbovirus and renal transplantation.

Transfusion of pathogen-reduced platelet components without leukoreduction

BACKGROUND

Leukoreduction (LR) of platelet concentrate (PC) has evolved as the standard to mitigate risks of alloimmunization, clinical refractoriness, acute transfusion reactions (ATRs), and cytomegalovirus infection, but does not prevent transfusion-associated graft-versus-host disease (TA-GVHD). Amotosalen-ultraviolet A pathogen reduction (A-PR) of PC reduces risk of transfusion-transmitted infection and TA-GVHD. In vitro data indicate that A-PR effectively inactivates WBCs and infectious pathogens.

STUDY DESIGN AND METHODS

A sequential cohort study evaluated A-PR without LR, gamma irradiation, and bacterial screening in hematopoietic stem cell transplant (HSCT) recipients. The first cohort received conventional PC (control) processed without LR, but with gamma irradiation and bacterial screening. The second cohort received A-PR PC (test) processed without: LR, bacterial screening, or gamma irradiation. The primary efficacy outcome was the 1-hour corrected count increment. The primary safety outcome was treatment-emergent ATR. Secondary outcomes included clinical refractoriness, and 100-day status for engraftment, TA-GVHD, HSCT-GVHD, infections, and mortality.

RESULTS

Mean corrected count increment (× 10³ ) of 33 test PC recipients was similar (18.9 ± 8.8 vs. 16.6 ± 8.4; p = 0.296) to that of 31 control PC recipients. Test recipients had a reduced, but nonsignificant, incidence of ATR (test = 9.1%, Control = 19.4%; p = 0.296). The frequencies of clinical refractoriness (0 of 33 vs. 4 of 31 patients) and refractory transfusions (6.6% vs. 19.3%) were lower in the test cohort (p = 0.05 and 0.02), respectively. No patient in either cohort had TA-GVHD. Day 100 engraftment, HSCT-GVHD, mortality, and infectious disease complications were similar between cohorts.

CONCLUSIONS

This study indicated that A-PR PC without LR, gamma irradiation, or bacterial screening is feasible for support of HSCT.

Dengue seroprevalence among asymptomatic blood donors during an epidemic outbreak in Central-West Brazil

Dengue virus (DENV) transmission by blood transfusion is an important route of viral acquisition during outbreaks. The prevalence of DENV markers (viral RNA, NS1, anti-DENV IgM, and IgG) among blood donors in Central-West Brazil has never been evaluated. Our aim was to evaluate the full set of serological and molecular markers for DENV among blood donors of the Federal District of Brazil during an extensive outbreak in 2016. We found an anti-DENV IgM prevalence of 6.74% (n = 32/475). Of 475, 20 samples (4.21%) were also anti-DENV IgG positive. All samples were non-reactive for NS1 and DENV RNA. Our results imply that a significant proportion of the tested donors had experienced asymptomatic infection. More studies are necessary to evaluate the real prevalence of DENV viremia in blood donors from the Federal District of Brazil and if specific measures are needed to routinely test the blood donors for DENV RNA during outbreaks.

Evaluation of the protective ability of plasma from Japanese individuals against mosquito-borne viral infections

Background

Most of the Japanese population is seropositive for anti-Japanese encephalitis virus (JEV) antibodies because of previous JEV vaccination or natural infection. Because the virological characteristics of JEV are similar to those of West Nile virus (WNV) and dengue virus (DENV), we hypothesized that anti-JEV antibodies can cross-react with WNV and DENV antigens, leading to protection against infection by these viruses.

Methods

Using isolated intravenous immunoglobulin (IVIG) from plasma collected in Japan, neutralizing activities against WNV and DENV and antibody-dependent enhancement (ADE) of these viral infections were evaluated using an in vitro assay to determine the potency of immunity against these viruses.

Results

The prepared IVIG showed considerable neutralizing activity of 2.57 log10 reduction factor against WNV infection but showed little effect against DENV infection. A strong correlation was observed between the neutralizing activity of individual plasma samples against JEV and WNV (ρ=0.768). Moreover, IVIG showed no significant ADE of WNV infection.

Conclusions

Based on these results, we presume that the Japanese population is generally protected from WNV infection. Furthermore, IVIG prepared from plasma donations from Japanese individuals is expected to be an effective therapeutic agent based on its neutralizing activity against JEV and WNV.

Asymptomatic dengue virus cases in misiones, Argentina: a seroprevalence study in the university population

Dengue infection may be asymptomatic and may produce the typical symptoms of a benign illness or serious hemorrhagic and often fatal symptoms. Asymptomatic cases are statistically relevant and quite variable depending on the geographic area under study. However, there are no reports of asymptomatic population infected by the dengue virus in Misiones. In this study, 288 samples were analyzed, and the IgG anti dengue antibodies detected accounted for 6.6% of cases, while 89% corresponded to individuals who lived with people diagnosed or suspected of having contracted dengue, p= <0.001.

Epidemic potential of Zika virus in Australia: implications for blood transfusion safety

BACKGROUND

Zika virus (ZIKV) is transfusion-transmissible. In Australia the primary vector, Aedes aegypti, is established in the north-east, such that local transmission is possible following importation of an index case, which has the potential to impact on blood transfusion safety and public health. We estimated the basic reproduction number (R ₀ ) to model the epidemic potential of ZIKV in Australian locations, compared this with the ecologically similar dengue viruses (DENV), and examined possible implications for blood transfusion safety.

STUDY DESIGN AND METHODS

Varying estimates of vector control efficiency and extrinsic incubation period, "best-case" and "worst-case" scenarios of monthly R ₀ for ZIKV and DENV were modeled from 1996 to 2015 in 11 areas. We visualized the geographical distribution of blood donors in relation to areas with epidemic potential for ZIKV.

RESULTS

Epidemic potential (R ₀ > 1) existed for ZIKV and DENV throughout the study period in a number of locations in northern Australia (Cairns, Darwin, Rockhampton, Thursday Island, Townsville, and Brisbane) during the warmer months of the year. R ₀ for DENV was greater than ZIKV and was broadly consistent with annual estimates in Cairns. Increased vector control efficiency markedly reduced the epidemic potential and shortened the season of local transmission. Australian locations that provide the greatest number of blood donors did not have epidemic potential for ZIKV.

CONCLUSION

We estimate that areas of north-eastern Australia could sustain local transmission of ZIKV. This early contribution to understanding the epidemic potential of ZIKV may assist in the assessment and management of threats to blood transfusion safety.

Duplex nucleic acid test for the detection of chikungunya and dengue RNA viruses in blood donations

BACKGROUND

Chikungunya (CHIKV) and dengue (DENV) viruses are primarily mosquito‐borne, but transfusion transmission can occur (DENV) or is likely (CHIKV). In the absence of commercially available blood screening assays, a variety of strategies to ensure recipient safety in the face of expanding CHIKV and/or DENV outbreaks have been used.

STUDY DESIGN AND METHODS

Performance of cobas CHIKV/DENV, a qualitative RNA detection assay for use on the cobas 6800/8800 Systems, was evaluated at two sites (Roche Molecular Systems, Inc. [RMS], and the American Red Cross [ARC]). Analytical sensitivity, genotype inclusion, correlation with other assays, and reproducibility used clinical CHIKV‐ or DENV‐positive samples and secondary standards for DENV Types 1 to 4 and for three CHIKV genotypes (Asian; East Central South African; and West African); each secondary standard was traceable to international reference panels or reagents. Evaluation of analytic specificity assessed other microorganisms for interference and cross‐reactivity; clinical specificity was determined by individually testing 10,528 volunteer blood donations from the continental United States.

RESULTS

The 50 and 95% limit of detection (LoD) obtained by RMS for CHIKV, Asian genotype was 1.8 and 6.8 Detectable Units (DU)/mL, respectively, and 0.14 and 0.63 International Units (IU)/mL, respectively for DENV‐1. No significant differences in detection occurred by testing at a second site, the ARC (2.4 and 10.5 DU/mL for CHIKV and 0.15 and 0.60 IU/mL for DENV). Clinical specificity was 100% (95% confidence interval, 99.965%‐100%) for CHIKV and DENV.

CONCLUSIONS

The high sensitivity and specificity of the cobas CHIKV/DENV test, as demonstrated in these evaluations, indicate its suitability for blood donation screening.

Seroprevalence of dengue fever and the associated sociodemographic, clinical, and environmental factors in Makkah, Madinah, Jeddah, and Jizan, Kingdom of Saudi Arabia

This study aimed to estimate the seroprevalence of anti-dengue IgG antibodies in Makkah, Al Madinah, Jeddah, and Jizan; and to identify the associated demographic, clinical, and environmental independent risk factors. A community-based household serosurvey conducted between September 20, 2016 and January 31, 2017. A multi-stage stratified cluster sampling was used to select 6596 participants from Makkah, Madinah, Jeddah, and Jizan. Blood samples were drawn from all participants to detect anti-dengue IgG antibodies. A semi-structured questionnaire was used to collect information on demographic, clinical, and environmental data. Multivariate logistic regression was carried out to identify independent risk factors of dengue seropositivity. The dengue seroprevalence (95% confidence intervalI) was 26.7% (25.6%, 27.8%), with the highest (33.6%) and lowest (14.8%) rates in Jizan and Madinah, respectively, and reaching 50% or more in several districts of the four cities. Demographic predictors of seroprevalence included: dwelling in Makkah (odds ratio [OR] = 2.19, p < 0.001) or Jizan (OR = 2.17, p < 0.001); older age (OR = 3.91, p < 0.001 for age>30 years); housing type (OR = 1.84 and 1.82, p < 0.001 for popular and social houses, respectively); and number of household occupants (OR = 0.86 and 0.71 for 6-10 [p = 0.042] and 11-20 [p = 0.002] occupants, respectively). Environmental predictors included the absence of pest control works in residency area (OR = 1.39, p = 0.002), presence of mosquitoes in the home (OR = 1.39, p = 0.001), and absence of awareness campaigns (OR = 1.97, p < 0.001). One in four inhabitants of the Western region of Saudi Arabia was seropositive for the dengue virus. Implementation of behavior-based educational programs is recommended, involving the population in the identification and eradication of vector sources and promoting appropriate behaviors that prevent the spread.

The Emergence of Zoonotic Pathogens as Agents of Concern in Transfusion Medicine

A variety of emerging infections are of interest to transfusion medicine clinicians, but zoonotic pathogens, those maintained in nonhuman hosts and transmitted to humans, have dominated recent discussions, especially emerging acute viral infections that can or might spread around a shrinking globe with unprecedented speed, in an infected human or an infected vector or reservoir host. Further, advanced pathogen discovery techniques (e.g., metagenomics) allow the identification of potential pathogens before their recognition as clinically relevant to transfusion medicine. In the aftermath of our experiences with HIV and posttransfusion hepatitis, our windows for response to such agents and infections have contracted rapidly. These characteristics pose difficult challenges for our development of surveillance and control regimes capable of timely, but appropriately nuanced, responses. This monograph surveys a selection of such agents, exploring their apparent relevance to transfusion medicine, closing with a framework for an ongoing approach to their surveillance, recognition, threat evaluation, and mitigation.

Risk of transfusion-associated dengue: screening of blood donors from Pune, western India

BACKGROUND

Dengue, a mosquito-borne viral disease, is endemic in >125 countries worldwide. The threat of blood-borne transmission of dengue virus (DENV) has been documented.

STUDY DESIGN AND METHODS

This study was conducted to assess the potential magnitude of transfusion-associated dengue, by determination of DENV seromarkers in blood donations from Pune, India, during two dengue seasons (2016 and 2017). These included DENV nonstructural protein 1 (NS1), anti-DENV immunoglobulin (Ig) M, anti-DENV IgG (enzyme-linked immunosorbent assay), and DENV RNA (reverse transcription-polymerase chain reaction).

RESULTS

NS1 (IgM) reactivity was 1 of 209, 0.48% (11/209, 5.3%) in 2016 and 2 of 311, 0.64% (20/311, 6.4%) in 2017. Of the 34 NS1/IgM reactives, 1 NS1-reactive donor and 10 IgM-reactive donors exhibited evidence of secondary infection. DENV RNA was not detected in any of the 34 NS1/IgM reactives. Among the NS1/IgM negatives, anti-DENV IgG reactivity was high in 2016 (75%) and further increased in 2017 (87%, p = 0.002).

CONCLUSION

Although RNA negative, detection of 34 NS1/IgM-reactive donations, of which 11 had evidence of secondary infection, suggests the need for further evaluation on the basis of potential risk to recipients of either dengue transmission or increased risk of secondary infection. These would include multicenter studies followed by cost-benefit analyses.

Seroprevalence of Dengue and Zika Virus in Blood Donations: A Systematic Review

The presence of antibodies to Zika virus (ZIKV) and dengue virus (DENV) can be detected in blood donations. Donation-based surveillance provides an alternative strategy to estimate population prevalence by detecting antibodies that are circulating. To estimate population prevalence, we conducted a systematic review of literature on the seroprevalence of ZIKV and DENV antibodies in blood donations. We searched PubMed and Web of Science for studies that reported the seroprevalence of ZIKV and DENV in blood donations. The title and abstract of each study were screened by 2 reviewers simultaneously for possible inclusion, and the full text of selected studies was reviewed to ensure that they met inclusion criteria (used primary data collection, reported evidence of immunoglobulin M (IgM) or immunoglobulin G (IgG) antibodies in the blood supply, and included a representative sample of the total population). Immunoglobin test measuring levels of antibodies to IgM and IgG and number of positive cases were extracted from each study. No exclusions were made based on language or country. Our initial search identified 1890 studies after excluding duplicates, of which 76 were assessed for full text eligibility to ensure that they met our final inclusion criteria. There were 14 studies included in our review; 11 examined the seroprevalence of DENV, and 3 examined ZIKV. The highest seroprevalence by IgM was 2.82% for DENV and 0.53% for ZIKV. Our results indicate that the seroprevalence of ZIKV and DENV antibody presence in countries with active transmission is higher than reports by traditional surveillance in some countries. This finding is expected due to the large percentage of asymptomatic cases. The highest seroprevalence was observed for IgG, which can persist over long periods of time compared to IgM. Screening of blood donations may help supplement traditional surveillance measures, especially during outbreak settings.

Low frequency of asymptomatic dengue virus-infected donors in blood donor centers during the largest dengue outbreak in Taiwan

To determine the prevalence of asymptomatic dengue virus-infected blood donors during the largest dengue outbreak in Taiwan history occurred in 2015, we examined the evidence of dengue virus (DENV) infection by the detection of DENV RNA genome using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), DENV NS1 antigen using rapid diagnosis test (RDT) and anti-dengue antibody using IgM/IgG capture enzyme-linked immunosorbent assay (capture ELISA) and RDT in eight thousand serum samples from blood donations to the blood centers of the Taiwan Blood Services Foundation (TBSF) in Kaohsiung City and Tainan City during the largest dengue outbreak in Taiwan history occurred in 2015. Only one serum sample was positive for DENV RNA detection by using dengue-specific real-time RT-PCR, the virus was DENV-2 determined by serotype-specific real-time RT-PCR and sequencing, and the DENVs in the serum were confirmed as being infectious by a plaque assay. The recipient of this blood did not develop any dengue fever symptom on follow-up. None of the samples was NS1 RDT-reactive. Seventeen IgM-positive samples were identified. There was a low prevalence of asymptomatic confirmed or probable DENV-infected blood donors in our study (0.013% and 0.21%, respectively), and no symptomatic transfusion-transmitted dengue (TT dengue) was developed during the largest dengue outbreak in Taiwan history in highly endemic areas and periods.

Budget impact of implementing platelet pathogen reduction into the Italian blood transfusion system

BACKGROUND

Despite improvements in blood donor selection and screening procedures, transfusion recipients can still develop complications related to infections by known and emerging pathogens. Pathogen reduction technologies (PRT) have been developed to reduce such risks. The present study, developed whithin a wider health technology assessment (HTA) process, was undertaken to estimate the costs of the continuing increase in the use of platelet PRT in Italy.

MATERIALS AND METHODS

A multidisciplinary team was established to perform the HTA and conduct a budget impact analysis. Quantitative data on platelet use were derived from the 2015 national blood transfusion report and from the Italian Platelets Transfusion Assessment Study (IPTAS). The current national fee of 60 Euro per platelet PRT procedure was used to quantify the costs to the Italian National Health Service (INHS). The analysis adopts a 3-year time-frame. In order to identify the impact on budget we compared a scenario representing an increased use of PRT platelets over time with a control scenario in which standard platelets are used.

RESULTS

Progressive implementation of PRT for 20%, 40% and 66% of annual adult platelet doses could generate an increase in annual costs for the INHS amounting to approximately 7, 14 and 23 million Euros, respectively. Use of kits and devices suitable for the treatment of multiple adult platelet doses in one PRT procedure could lower costs.

DISCUSSION

In order to fully evaluate the societal perspective of implementing platelet PRT, the increase in costs must be balanced against the expected benefits (prevention of transfusion-transmissible infections, white cell inactivation, extension of platelet storage, discontinuation of pathogen detection testing). Further studies based on actual numbers of platelet transfusion complications and their societal cost at a local level are needed to see the full cost to benefit ratio of platelet PRT implementation in Italy, and to promote equal treatment for all citizens.

Parental and offspring larval diets interact to influence life-history traits and infection with dengue virus in Aedes aegypti

The environmental conditions experienced by parents can influence offspring phenotype along with the conditions experienced by offspring. These parental effects are clear in organisms that display parental care and are less clear in other organisms. Here, we consider effects of parental and offspring larval nutrition on offspring development time, survivorship and infection with dengue virus in Aedes aegypti, the mosquito vector of dengue, chikungunya, yellow fever and Zika. Parents were raised on either high or low larval detritus inputs with subsequent offspring being divided into two groups, one receiving high nutrients and the other low. Low nutrient females from low nutrient parents (LL) developed significantly slower than those from high nutrient parents (HL). Females from all parent by offspring nutrient treatment groups were equally likely to become infected with dengue virus at 24 h, 3 days and 14 days. After 14 days, high nutrient females from low nutrient parents (LH) had 11 times higher viral titres and more disseminated infections than high nutrient females from high nutrient parents (HH). These results suggest that carry-over environmental stress from the parental generation can influence life histories and arbovirus infection in Ae. aegypti females. We found males to be robust to the life-history parameters measured, suggesting sex-specific differences which may relate to their lower nutrient requirements for metamorphosis.

Characterization of efficacy and safety of pathogen inactivated and quarantine plasma in routine use for treatment of acquired immune thrombotic thrombocytopenic purpura

BACKGROUND

Auto-immune thrombotic thrombocytopenic purpura (TTP) is a morbid multi-organ disorder. Cardiac involvement not recognized in initial disease descriptions is a major cause of morbidity. Therapeutic plasma exchange (TPE) requires exposure to multiple plasma donors with risk of transfusion-transmitted infection (TTI). Pathogen inactivation (PI) with amotosalen-UVA, the INTERCEPT Blood System for Plasma (IBSP) is licensed to reduce TTI risk.

METHODS

An open-label, retrospective study evaluated the efficacy of quarantine plasma (QP) and IBSP in TTP and defined treatment emergent cardiac abnormalities. Medical record review of sequential patient cohorts treated with QP and IBSP characterized efficacy by remission at 30 and 60 days (d) of treatment, time to remission, and volume (L/kg) of plasma required. Safety outcomes focused on cardiac adverse events (AE), relapse rates, and mortality.

RESULTS

Thirty-one patients (18 IBSP and 13 QP) met study criteria for auto-immune TTP. The proportions (%) of patients in remission at 30 d (IBSP = 61·1, QP = 46·2, P = 0·570) and 60 d (IBSP = 77·8, QP = 76·9, P = 1·00) were not different. Median days to remission were less for IBSP (15·0 vs. 24·0, P = 0·003). Relapse rates (%) 60 d after remission were not different between cohorts (IBSP = 7·1, QP = 40·0, P = 0·150). ECG abnormalities before and during TPE were frequent; however, cardiac AE and mortality were not different between treatment cohorts.

CONCLUSIONS

Cardiac and a spectrum of ECG findings are common in TTP. In this study, IBSP and QP had similar therapeutic profiles for TPE.