Transfusion-transmitted CMV infection - current knowledge and future perspectives

Renal transplantation using kidneys from a donor with high grade cytomegalovirus viraemia: case report and literature review

Transplanting organs from cytomegalovirus-seropositive donors into cytomegalovirus-seronegative recipients is an accepted practice. However, outcomes following transplantation of organs from donors with active cytomegalovirus disease are unknown. We present a case involving a patient aged 61 years with end-stage renal disease, seropositive for cytomegalovirus, who underwent dual kidney transplant from a donor with high-grade cytomegalovirus viraemia. The donor was on immunosuppressive therapy for systemic lupus erythematosus and interstitial lung disease and had been admitted with respiratory failure. The donor had high-grade cytomegalovirus viraemia with probable cytomegalovirus pneumonitis (cytomegalovirus viral load >100 000 international units [IU]/mL in plasma and 319 000 IU/mL in bronchoalveolar lavage). Renal biopsy at organ procurement showed the absence of cytomegalovirus inclusions. Following transplantation, the recipient had delayed graft function, with renal recovery after 1 week. The patient received basiliximab induction and standard tacrolimus-based maintenance immunosuppression. He received ganciclovir and valganciclovir treatment for 1 month, followed by valganciclovir prophylaxis (or viral load monitoring, when prophylaxis had to be paused) for 2 additional months to prevent donor-derived cytomegalovirus infection. Transient cytomegalovirus viraemia (peaking at 4480 IU/mL) developed at 4 months and resolved with 1 month of valganciclovir treatment. The patient is doing well 1 year after transplantation, with adequate kidney function. This case highlights the successful and safe transplantation of kidneys from a donor with cytomegalovirus disease into a cytomegalovirus-seropositive recipient. Further research is needed to confirm our findings and define post-transplantation management.

Seroprevalence of Anti-Cytomegalovirus Antibodies in Pregnant Women from South-West Romania

Cytomegalovirus (CMV), in addition to other agents, is part of the TORCH complex (Toxoplasma gondii, Rubella virus, Cytomegalovirus, Herpes simplex viruses, and other agents). CMV infection is the most frequent cause of congenital malformations. This study aimed to establish the variation of prevalence of anti-CMV antibodies in pregnant women from the South-West region of Romania, according to demographic factors, such as age and area of residence, in two separate time periods (2013-2016 and 2019-2022). We collected from the hospital records the age, place of residence, and anti-CMV antibody test results using immune electrochemiluminescence and chemiluminescence. This study found that the seroprevalence of anti-CMV IgM antibodies increased slightly from 2013-2016 to 2019-2022, from 1.92% to 2.26%, and for IgG antibodies from 93.68% to 94.96%. In both groups was observed a descending trend of anti-CMV IgM seroprevalence with an increase in age, showing a decrease in seroprevalence from 3.57% to 1.09% in pregnant women from rural areas in the 31-35 years age group, while in urban areas, we observed a decrease in seroprevalence from 11.11% to 3.06% in the <20 years age group. The IgG seroprevalence showed an increase both in rural areas (from 93.97% to 95.52%) and urban areas (from 93.52% to 94.27%). In both groups, seroprevalence was higher in rural areas compared to urban regions. These results show a high rate of immunization against CMV in pregnant women in South-West Romania, which led to a low risk of acquiring the primary infection during pregnancy. However, the increase in the rate of primary CMV infections in pregnancy suggests the need for prioritizing screening programs and improving the existing protocols to enhance maternal and child healthcare.

Neonatal Blood Banking Practices

There is little formal guidance to direct neonatal blood banking practices and, as a result, practices vary widely across institutions. In this vulnerable patient population with a high transfusion burden, considerations for blood product selection include freshness, extended-storage media, pathogen inactivation, and other modifications. The authors discuss the potential unintended adverse impacts in the neonatal recipient. Concerns such as immunodeficiency, donor exposures, cytomegalovirus transmission, volume overload, transfusion-associated hyperkalemia, and passive hemolysis from ABO incompatibility have driven modifications of blood components to improve safety.

Immunohematological testing and transfusion management of the prenatal patient

The primary indication for immunohematological testing in the prenatal patient is to detect and identify maternal red cell antibodies. If there are antibodies that are expected to hemolyze the fetus' red cells, their strength of reactivity must be tested, and the fetus' antigen status determined. After delivery, testing is performed to assess the extent of fetomaternal hemorrhage, as a large hemorrhage may require other therapeutic interventions. Another major role for immunohematological testing is to select blood components appropriately when intrauterine transfusion is required for fetal anemia resulting from maternal alloimmunization or some other cause. Supplementation with molecular methods has transformed the practice of immunohematology, particularly as it applies to typing for the D antigen of the Rh blood group system. Notwithstanding the advances in testing, close coordination and communication between the transfusion service and the obstetrics service are the foundation for ensuring the finest care for prenatal patients, and for new mothers and their infants. This review describes testing and transfusion practices for prenatal patients, using case presentations to highlight the management of selected immunohematological findings. It also includes a discussion of key patient management topics that are currently unresolved.

Cytomegalovirus Disease as a Risk Factor for Invasive Fungal Infections in Liver Transplant Recipients under Targeted Antiviral and Antimycotic Prophylaxis

Cytomegalovirus (CMV) infection is the most common opportunistic infection that occurs following orthotopic liver transplantation (OLT). In addition to the direct infection-related symptoms, it also triggers an immunological response that may contribute to adverse clinical outcomes. CMV disease has been described as a predictor of invasive fungal infections (IFIs) but its role under an antiviral prophylaxis regimen is unclear.

METHODS

We retrospectively analyzed the medical records of 214 adult liver transplant recipients (LTRs). Universal antiviral prophylaxis was utilized in recipients with CMV mismatch; intermediate- and low-risk patients received pre-emptive treatment.

RESULTS

Six percent of patients developed CMV disease independent of their serostatus. The occurrence of CMV disease was associated with elevated virus load and increased incidence of leucopenia and IFIs. Furthermore, CMV disease was associated with higher one-year mortality and increased relapse rates within the first year of OLT.

CONCLUSIONS

CMV disease causes significant morbidity and mortality in LTRs, directly affecting transplant outcomes. Due to the increased risk of IFIs, antifungal prophylaxis for CMV disease may be appropriate. Postoperative CMV monitoring should be considered after massive transfusion, even in low-risk serostatus constellations. In case of biliary complications, biliary CMV monitoring may be appropriate in the case of CMV-DNA blood-negative patients.

Transfusion-Transmitted Disorders 2023 with Special Attention to Bone Marrow Transplant Patients

Transfusion medicine is traditionally a strong/fundamental part of clinical practice, saving hundreds of millions of lives. However, blood-borne or transmitted infections are a well-known and feared possibility, a risk we relentlessly mitigate. Pathogens are continuously and rather quickly changing, so during the last decade, many, sometimes exotic, new pathogens and diseases were recorded and analyzed, and some of them were proved to be transmitted with transfusions. Blood or blood component transfusions are carried out after cautious preparative screening and inactivation maneuvers, but in some instances, newly recognized agents might escape from standard screening and inactivation procedures. Here, we try to focus on some of these proven or potentially pathogenic transfusion-transmitted agents, especially in immunocompromised patients or bone marrow transplantation settings. These pathogens are sometimes new challenges for preparative procedures, and there is a need for more recent, occasionally advanced, screening and inactivation methods to recognize and eliminate the threat a new or well-known pathogen can pose. Pathogen transmission is probably even more critical in hemophiliacs or bone marrow transplant recipients, who receive plasma-derived factor preparations or blood component transfusions regularly and in large quantities, sometimes in severely immunosuppressed conditions. Moreover, it may not be emphasized enough that transfusions and plasma-derived product administrations are essential to medical care. Therefore, blood-borne transmission needs continued alertness and efforts to attain optimal benefits with minimized hazards.

Cytomegalovirus in donors for fecal microbiota transplantation, the phantom menace?

BACKGROUND

Fecal Microbiota Transplantation (FMT) has become the preferred treatment for recurrent Clostridioides difficile Infections (CDI). However, donor screening is a complex process that varies between countries. The primary objective of screening is to prevent the transfer of potential pathogens from the donor to the recipient via feces. Many guidelines recommend Cytomegalovirus (CMV) testing as part of donor screening, but is the risk of CMV transmission well supported by evidence?

MATERIALS/METHODS

A French prospective cross-sectional multicenter single-arm study estimated the frequency of detection of CMV in the stool of voluntary healthy donors selected for FMT. All preselected donors were tested for CMV antibodies in blood, and if positive, CMV DNA PCR was performed on whole blood and stool. For samples CMV positive in stool PCR, or case of serological markers positive for IgM, we planned isolation of CMV in cell culture.

RESULTS

From June 1, 2016, to July 31, 2017, 500 healthy donors (250 per center) were recruited and 483 included. Of these, 301 were CMV seronegative, and 182 tested positive for CMV IgM and/or IgG. Stool CMV PCR was performed in 162 donors. In two cases, the initial analysis was positive, but below the limit of quantification. Repeated PCR tests using Siemens and Altostar assays were negative. No infectious CMV could be detected in cell culture of these two samples and in the stool of 6 CMV IgM-positive donors.

CONCLUSIONS

Our study shows that healthy volunteers with positive CMV serology do not shed CMV DNA in their stool, as detected by PCR or cell culture. This study provides another argument to remove CMV screening for FMT donors.

Association between active cytomegalovirus infection and lung fibroproliferation in adult patients with acute respiratory distress syndrome: a retrospective study

Background

Cytomegalovirus (CMV) has high seroprevalence, and its active infection is associated with several adverse prognoses in adult patients with acute respiratory distress syndrome (ARDS). However, the role of active CMV infection in ARDS-associated fibroproliferation is unknown. This study aimed at determining the association between active CMV infection and lung fibroproliferation in adult patients with ARDS.

Methods

We retrospectively reviewed the medical records of all adult patients with ARDS who were admitted to the intensive care unit (ICU) from January 2018 to December 2020 at a national university-affiliated hospital in China. Study subjects were divided into active and non-active CMV infection groups based on CMV DNAemia within a 28-day ICU hospitalization. Lung fibroproliferation was measured using chest high-resolution computed tomography (HRCT) and N-terminal peptide of serum procollagen III (NT-PCP-III) within the first 28 days of ICU admission. Pulmonary fibrosis, clinical features, laboratory findings, treatment measures, and clinical outcomes were compared between the two groups.

Results

Among the 87 ARDS patients included in this study, the incidence of active CMV infection was 16.1% within the 28-day ICU admission period. In logistic regression analyze, active CMV infection was found to be associated with higher pulmonary fibrogenesis, pulmonary fibrosis score, and NT-PCP-III level (P < 0.05). The duration of ICU stay in ARDS patients with active CMV infection was significantly higher than in those without active CMV infection (P < 0.05).

Conclusions

Among adult patients with ARDS, active CMV infection was related to poor clinical outcomes. Active CMV infection was associated with ARDS-associated fibroproliferation. Prophylactic and preemptive use of anti-CMV agents on pulmonary fibrosis should be assessed to determine a consensus therapeutic strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07747-y.

Blood Product (Donor) Noninfectious and Infectious Testing and Modification

Blood transfusion begins with safe donor selection and testing. In the United States, the blood supply and transfusion are highly regulated. Blood transfusion safety is multifaceted, whereby each of the elements of the blood safety value chain, spanning donor recruitment and qualification, to collection, blood processing, testing, transfusion practice, and posttransfusion surveillance, must be optimized to minimize risk. Pathogen inactivation is a promising approach to decrease bacterial contamination of platelets, inactivate parasites and viruses, and decrease risks associated with emerging and unidentified pathogens. This article offers an overview of blood donor infectious and noninfectious testing in the United States.

Cytomegalovirus reactivation in immunocompetent mechanical ventilation patients: a prospective observational study

BACKGROUND

Cytomegalovirus (CMV) reactivation is associated with adverse prognoses of critically ill patients. However, the epidemiology and predictors of CMV reactivation in immunocompetent patients receiving mechanical ventilation (MV) are not clear. The aim of this study was to investigate the epidemiology and predictors of CMV reactivation in immunocompetent patients requiring MV.

METHODS

A single-center, prospective observational study (conducted from June 30, 2017 to July 01, 2018) with a follow-up of 90 days (September 29, 2018) that included 71 CMV-seropositive immunocompetent patients with MV at a 37-bed university hospital general intensive care unit (ICU) in China. Routine detection of CMV DNAemia was performed once a week for 28 days (Days 1, 7, 14, 21, and 28). CMV serology, laboratory findings, and clinical data were obtained during hospitalization.

RESULTS

Among 71 patients, 13 (18.3%) showed CMV reactivation within 28 days in the ICU. The median time to reactivation was 7 days. CMV reactivation was related to various factors, including body mass index (BMI), sepsis, N-terminal pro-b-type natriuretic peptide (NT-proBNP), blood urea nitrogen (BUN), and hemoglobin (Hb) levels (P < 0.05). In the multivariate regression model, BMI, Hb level, and sepsis were independently associated with CMV reactivation patients (P < 0.05). Moreover, the area under the receiver operating characteristic (AUROC) of BMI, Hb, and BMI combined with Hb was 0.69, 0.70, and 0.76, respectively. The duration of MV, hospitalization expense, length of ICU stay, and 90 day all-cause mortality rate in patients with CMV reactivation was significantly higher than in those without CMV reactivation (P < 0.05).

CONCLUSIONS

Among immunocompetent patients with MV, the incidence of CMV reactivation was 18.3%. CMV reactivation was associated with several adverse prognoses. BMI, Hb, and sepsis were independent risk factors for CMV reactivation. BMI and Hb may predict CMV reactivation.

Cytomegalovirus seroprevalence among blood donors: a systematic review and meta-analysis

Background

Screening for cytomegalovirus (CMV)-specific antibodies is not routine in some settings. Thus, transfusion of blood products poses risks for susceptible individuals.

Objectives

To investigate the global pooled CMV seroprevalence among volunteer blood donors.

Methods

This systematic review and meta-analysis was performed according to PRISMA guidelines. The databases searched included Embase, Google Scholar, Medline, PubMed, Web of Science, and Cochrane Library. Data were extracted independently and analyzed using STATA version 11.

Results

The global seroprevalence of CMV IgG, CMV IgM, and both CMV IgM and IgG was 83.16% (95% confidence interval [CI]: 78.55–87.77%, I² = 99.5%), 13.77% (95% CI: 11.59–15.95%, I² = 98.8%), and 23.78% (95% CI: 10.50–37.06%, I² = 98.7), respectively.

Conclusion

The global seroprevalence of CMV was high among blood donors. Therefore, regular CMV screening should be conducted to identify CMV-seronegative blood donors.

Insight for Immunotherapy of HCMV Infection

Human cytomegalovirus (HCMV), a ubiquitous in humans, has a high prevalence rate. Young people are susceptible to HCMV infection in developing countries, while older individuals are more susceptible in developed countries. Most patients have no obvious symptoms from the primary infection. Studies have indicated that the virus has gradually adapted to the host immune system. Therefore, the control of HCMV infection requires strong immune modulation. With the recent advances in immunotherapy, its application to HCMV infections is receiving increasing attention. Here, we discuss the immune response to HCMV infection, the immune escape mechanism, and the different roles that HCMV plays in various types of immunotherapy, including vaccines, adoptive cell therapy, checkpoint blockade therapy, and targeted antibodies.

CMV, B and C hepatitis among multi-transfused hereditary hemolytic Anemia children: an updated Egyptian experience

BACKGROUND AND OBJECTIVES

Regular blood transfusion has improved the overall survival and quality of life for patients with hereditary hemolytic anemias. Nevertheless, it carries a real risk of acquisition of blood-borne virus infections, especially viral hepatitis. The purpose of the current study is to present an Egyptian update on blood-borne hepatitis C & B viruses (HCV & HBV) and cytomegalovirus (CMV) among multi-transfused Egyptian children with hereditary hemolytic anemias, especially after implementation of national preventive programs in Egypt.

PATIENTS AND METHODS

All pediatric patients with hereditary hemolytic anemias who have regular follow-up and received frequent blood transfusion at the Pediatric Hematology Units, Menuofia and Zagazig Universities Hospitals, Egypt, during the study period, were recruited. They were tested for hepatitis B surface antigen (HBVsAg), hepatitis C antibody (HCVab), and CMV immunoglobulin M (IgM) serology. Those with positive results were confirmed by real-time polymerase chain reaction (PCR).

RESULTS

Four hundred and seventy-seven hereditary hemolytic anemia patients fulfilled the study inclusion criteria. Their ages ranged from 2 to 18 years, 54.9% of them were males. Seroprevalence of HCVab and CMV-IgM were (14.7% & 6.7% respectively) and they were confirmed by PCR. None of the studied cases were HBVsAg positive. Seropositivity for HCV was significantly associated with older age of the patients, higher transfusion frequency, longer disease duration, and higher mean serum ferritin.

CONCLUSION

HCV followed by CMV infections still represent a significant problem for patients with hereditary hemolytic anemias. Nationwide plans should be taken to ensure meticulous and highly sensitive methods of blood screening before transfusion. On the other hand, it seems that HBV compulsory vaccination had succeeded to eliminate HBV infection.

High Rate of Cytomegalovirus Detection in Cholestatic Preterm Infants

Objectives: To evaluate the prevalence of cytomegalovirus (CMV) infection in preterm infants with cholestasis. Study design: Preterm infants (<37 weeks gestational age) with cholestasis were tested for CMV DNA using Taqman PCR in blood cells from sedimented whole blood, plasma, and urine. Infants were regarded as positive for CMV if any sample was tested positive. Their mothers were tested for CMV serostatus simultaneously. A control group of non-cholestatic preterm infants, and their mothers, were tested at a similar age. Results: A total of 69 preterm infants with a median gestational age of 26 weeks and 5 days were included, 45 cholestatic and 24 non-cholestatic. Of the cholestatic infants, 31/45 (69%) were CMV positive vs. 3/24 (13%) of the non-cholestatic infants (p < 0.001). Cholestatic infants were equally preterm as the non-cholestatic ones, but were more severely ill. After adjusting for the risk factors necrotizing enterocolitis, prolonged parenteral nutrition, and gestational age, being CMV positive remained significantly associated with cholestasis in a multivariable logistic regression model. Characteristics of CMV-positive and -negative cholestatic infants showed differences only for necrotizing enterocolitis, occurring in 55% (17/31) of CMV positive vs. 21% (3/14) of CMV negative (p = 0.054), and mortality. Eight cholestatic CMV-positive infants died (26%) vs. none of the CMV-negative infants (p = 0.044). Conclusions: CMV DNA was detected in two out of three cholestatic preterm infants, by far more often than in the non-cholestatic control group. Cholestasis with simultaneous detection of CMV DNA may be associated with increased mortality.

Cytomegalovirus and Epstein-Barr Infections: Prevalence and Impact on Patients with Hematological Diseases

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections are widely distributed throughout the world. EBV is linked to various hematological and autoimmune disorders whereas CMV might play important role in the progression of chronic hematological diseases, such as hemoglobinopathies, lymphomas, myelomas, hemophilia, and aplastic and sickle cell anemia. Both viruses produce a viral homolog of human interleukin-10 that can cause general suppression of immune response, increasing susceptibility to other infections. These viruses can remain latent in the host cells and be reactivated when the host immune system is compromised. Studies showing the impact of CMV and EBV infections on hematological disorders are scarce and unclear in the context of coinfection. This review intends to present the biology, prevalence, and impact of CMV and EBV infections in patients with hematological diseases.

Infectious complications in neonatal transfusion: Narrative review and personal contribution

Neonates and prematures are among the most transfused categories of patients. Adverse reactions due to transfusions, such as transfusion-transmitted infections, can affect the rest of their lives. In this systematic review, we revised the literature concerning transfusion-transmitted infection in neonates. We reported case-reports and case-series previously published and we integrated these data with our experience at local neonatal intensive care unit. Moreover, we illustrated strategies for mitigating transfusion-transmitted infections, including donor selection and testing, pathogen inactivation technologies and combined approaches, as for Cytomegalovirus infection, integrating leukoreduction and identification of seronegative donors.

Metagenomic analysis and identification of emerging pathogens in blood from healthy donors

Emerging infectious pathogens that threaten blood transfusions are known to be present in blood samples from healthy/qualified donors. The objective of this study was to investigate the microbiome of blood from healthy donors from the Luzhou area in southwestern China. Potential pathogens and cytomegalovirus (CMV) infection in the donor blood were identified. Total plasma nucleic acids were extracted from one pool of 5734 samples and were constructed for metagenomics analysis using Illumina sequencing. The microbiome and potential emerging/re-emerging pathogens were identified using bioinformatics analysis. Moreover, CMV antigen was measured via an enzyme-linked immunosorbent assay, and the CMV DNA level was assessed by quantitative RT-PCR. A total of 132 bacterial reads, 65 viral reads and 165 parasitic reads were obtained. The most frequent bacterium was Escherichia coli (95/132, 72%) with 95 reads in 132 bacterial reads, and the most prevalent parasite was Toxoplasma gondii (131/165, 79%). Among the viruses, cytomegalovirus (44/65, 68%) accounted for the highest frequency, followed by Hepatitis E Virus (10/65, 15%). Moreover, the positive rate of CMV-IgG was 46.25% (2652/5734), and the positive rate of CMV-IgM was 5.82% (334/5734). The positive rate of dual positive (IgG+ and IgM+) CMV was 0.07% (4/5734). Twenty-one (0.37%) specimens from 5734 donated blood samples were positive for CMV DNA. The CMV DNA levels ranged from 7.56 × 10² to 3.58 × 10³ copies/mL. The current study elucidated the microbiome structure in blood from healthy/qualified donors in the Luzhou area and identified emerging/re-emerging pathogens. This preliminary study contributes to information regarding blood transfusion safety in China.

Transfusion support for stem cell transplant recipients

Hematopoietic stem cell patients regularly require transfusion support. Indications for transfusion in this population are similar to other patients being treated with chemoradiation; however, special considerations must be made in regards to pretransfusion testing, ABO compatibility, product modifications, and anticipated challenges while patients undergo engraftment. Additionally, infusion of hematopoietic stem cells requires acute understanding of product collection, modification, and potential side effects. As these patients often require numerous platelet transfusions, platelet refractoriness may be encountered and practice options are discussed. We review current indications and guidelines for transfusion in hematopoietic stem cell patients and make recommendations for best practice based on current literature.

Transfusion-transmitted cytomegalovirus: behaviour of cell-free virus during blood component processing. A study on the safety of labile blood components in Switzerland

BACKGROUND

Nowadays, most blood products are leukocyte-reduced. After this procedure, the residual risk for transfusion transmitted cytomegalovirus (TT-CMV) is mostly attributed to cell-free viruses in the plasma of blood donors following primary infection or viral reactivation. Here, objectives are: 1) to study the behaviour of cell-free CMV through the blood component processing; 2) to determine the anti-CMV seroprevalence, the level of viremia, the window-period in blood donor population; and 3) to identify cases of TT-CMV in bone marrow transplant (BMT) recipients.

MATERIALS AND METHODS

Cell-free CMV was injected into blood bags originating from regular donors. Blood components were processed according to either the CompoSelect^® or the CompoFlow^® (Fresenius Kabi AG) techniques. Samples were analysed at each step for presence of virus DNA using quantitative polymerase chain reaction (PCR). The anti-CMV seroprevalence in our donor population was taken from our donor data system. The viremia was assessed in pooled plasmas samples from routine donations by quantitative PCR. Medical charts of 165 BMT anti-CMV seronegative recipients/anti-CMV seronegative donors who received CMV-unscreened blood products were reviewed.

RESULTS

Cell-free CMV passes without any decrease in viral load through all stages of blood processing. The anti-CMV seroprevalence was 46.13%. Four DNA positive samples out of 42,240 individual blood donations were identified (0.009%); all had low levels of viremia (range 11-255 IU/mL). No window-period donation was identified. No TT-CMV was found.

DISCUSSION

Cell-free CMV remains a concern with current blood component processing as it passes through all the processes. However, since low levels of CMV DNA were identified in the donations tested, and no BMT recipients had TT-CMV, the residual threat of TT-CMV after leukocyte reduction appears to be very low.

Blood Transfusion-Associated Infections in the Twenty-First Century: New Challenges

Blood transfusions are vital components of modern medical treatment to which there is no viable alternative despite efforts to create artificial blood. Each year thousands of lives are saved by blood transfusions in every country of the world. However, blood and blood products can result in significant adverse events including immunologic reactions, infections, inefficacy, and others which can sometimes result in death and severe disability. Thus, the sustainability of safe blood systems and costs are considered to be at crisis level. In industrialized countries, the risk of transfusion-transmitted infections such as HIV, syphilis, hepatitis viruses B and C are very low [generally [<1 in a million units], but in developing countries [especially in Africa] blood safety is still not assured. Compounding the problem of blood/product safety with respect to infectious agents are new emerging infectious microbes that are not being routinely tested for in blood that are donated. This chapter reviews the infectious risk of blood transfusions, types, mode and geographic variation, and the methods being used by blood services to attenuate and prevent these risks.

Cytomegalovirus (CMV) Pneumonitis: Cell Tropism, Inflammation, and Immunity

Human cytomegalovirus (HCMV) is an opportunistic pathogen causing disease mainly in immunocompromised patients or after congenital infection. HCMV infection of the respiratory tract leads to pneumonitis in the immunocompromised host, which is often associated with a bad clinical course. The related mouse cytomegalovirus (MCMV) likewise exhibits a distinct tropism for the lung and thus provides an elegant model to study host-pathogen interaction. Accordingly, fundamental features of cytomegalovirus (CMV) pneumonitis have been discovered in mice that correlate with clinical data obtained from humans. Recent studies have provided insight into MCMV cell tropism and localized inflammation after infection of the respiratory tract. Accordingly, the nodular inflammatory focus (NIF) has been identified as the anatomical correlate of immune control in lungs. Several hematopoietic cells involved in antiviral immunity reside in NIFs and their key effector molecules have been deciphered. Here, we review what has been learned from the mouse model with focus on the microanatomy of infection sites and antiviral immunity in MCMV pneumonitis.

Risk of cytomegalovirus transmission by blood products after solid organ transplantation

Cytomegalovirus (CMV) infection and CMV disease are significant contributors to increased morbidity, mortality, and cost for immunocompromised solid organ transplant recipients. Although the most significant risk for CMV transmission is the CMV serological status of the transplant donor and recipient, exposure to blood products is another potential risk factor. Before the era of leukocyte reduction, CMV seronegative products were issued to reduce the risk of CMV transmission, thus rendering the products CMV safe. This approach requires maintenance of two inventories of blood products and continuous donor testing. Leukocyte-reduced cellular transfusion products are also considered CMV safe and are essentially universally available. To minimize the risk of CMV infection in transplant recipients, strategies include use of seronegative blood products or prestorage leukocyte reduction. However, no recent randomized prospective controlled trial directly compares the two CMV safety approaches for transplant recipients. Hence, current policy relies on historic trials and more recent observational studies. As a consequence, though generally considered equivalent approaches, preferred practice varies between centers. This review provides guidance to inform an acceptable practice approach.

Blood transfusion safety in sub-Saharan Africa: A literature review of changes and challenges in the 21st century

BACKGROUND

Access to a safe, adequate blood supply has proven challenging in sub-Saharan Africa, where systemic deficiencies spanning policy, collections, testing, and posttransfusion surveillance have long been recognized. Progress in transfusion safety in the early 2000s was in large part due to intervention by the World Health Organization and other foreign governmental bodies, coupled with an influx of external funding.

STUDY DESIGN AND METHODS

A review of the literature was conducted to identify articles pertaining to blood safety in sub-Saharan Africa from January 2009 to March 2018. The search was directed toward addressing the major elements of the blood safety chain, in the countries comprising the World Health Organization African region. Of 1380 articles, 531 met inclusion criteria and 136 articles were reviewed.

RESULTS

External support has been associated with increased recruitment of voluntary donors and expanded testing for the major transfusion-transmitted infections (TTIs). However, the rates of TTIs among donors remain high. Regional education and training initiatives have been implemented, and a tiered accreditation process has been adopted. However, a general decline in funding for transfusion safety (2009 onwards) has strained the ability to maintain or improve transfusion-related services. Critical areas of need include data collection and dissemination, epidemiological surveillance for TTIs, donor recruitment, quality assurance and oversight (notably laboratory testing), and hemovigilance.

CONCLUSION

Diminishing external support has been challenging for regional transfusion services. Critical areas of deficiency in regional blood transfusion safety remain. Nonetheless, substantive gains in education, training, and accreditation suggest durable gains in regional capacity.

Selective 4-Thiouracil Labeling of RNA Transcripts within Latently Infected Cells after Infection with Human Cytomegalovirus Expressing Functional Uracil Phosphoribosyltransferase

Infections with human cytomegalovirus (HCMV) are highly prevalent in the general population as the virus has evolved the capacity to undergo distinct replication strategies resulting in lytic, persistent, and latent infections. During the latent life cycle, HCMV resides in subsets of cells within the hematopoietic cell compartment, including hematopoietic progenitor cells (HPCs) and peripheral blood monocytes. Since only a small fraction of these cell types harbor viral genomes during natural latency, identification and analysis of distinct changes mediated by viral infection are difficult to assess. In order to characterize latent infections of HPCs, we used an approach that involves complementation of deficiencies within the human pyrimidine salvage pathway, thus allowing for conversion of labeled uracil into rUTP. Here, we report the development of a recombinant HCMV that complements the defective human pyrimidine salvage pathway, allowing incorporation of thiol containing UTP into all RNA species that are synthesized within an infected cell. This virus grows to wild-type kinetics and can establish a latent infection within two distinct culture models of HCMV latency. Using this recombinant HCMV, we report the specific labeling of transcripts only within infected cells. These transcripts reveal a transcriptional landscape during HCMV latency that is distinct from uninfected cells. The utility of this labeling system allows for the identification of distinct changes within host transcripts and will shed light on characterizing how HCMV establishes and maintains latency.IMPORTANCE HCMV is a significant pathogen that accounts for a substantial amount of complications within the immunosuppressed and immunocompromised. Of particular significance is the capacity of HCMV to reactivate within solid tissue and bone marrow transplant recipients. While it is known that HCMV latency resides within a fraction of HPCs and monocytes, the exact subset of cells that harbor latent viral genomes during natural infections remain uncharacterized. The capacity to identify changes within the host transcriptome during latent infections is critical for developing approaches that therapeutically or physically eliminate latent viral genome containing cells and will represent a major breakthrough for reducing complications due to HCMV reactivation posttransplant. In this report, we describe the generation and use of a recombinant HCMV that allows specific and distinct labeling of RNA species that are produced within virally infected cells. This is a critical first step in identifying how HCMV affects the host cell during latency and more importantly, allows one to characterize cells that harbor latent HCMV.

The Potential Harm of Cytomegalovirus Infection in Immunocompetent Critically Ill Children

Cytomegalovirus (CMV) is a ubiquitous infection that causes disease in congenitally infected children and immunocompromised patients. Although nearly all CMV infections remain latent and asymptomatic in immunologically normal individuals, numerous studies have found that systemic viral reactivation is common in immunocompetent critically ill adults, as measured by detection of CMV in the blood (viremia). Furthermore, CMV viremia is strongly correlated with adverse outcomes in the adult intensive care unit (ICU), including prolonged stay, duration of mechanical ventilation, and death. Increasing evidence, including from a randomized clinical trial of antiviral treatment, suggests that these effects of CMV may be causal. Therefore, interventions targeting CMV might improve outcomes in adult ICU patients. CMV may have an even greater impact on critically ill children, particularly in low and middle income countries (LMIC), where CMV is regularly acquired in early childhood, and where inpatient morbidity and mortality are inordinately high. However, to date, there are few data regarding the clinical relevance of CMV infection or viremia in immunocompetent critically ill children. We propose that CMV infection should be studied as a potential modifiable cause of disease in critically ill children, and that these studies be conducted in LMIC. Below, we briefly review the role of CMV in immunologically normal critically ill adults and children, outline age-dependent differences in CMV infection that may influence ICU outcomes, and describe an agenda for future research.

Perioperative red blood cell transfusion in orofacial surgery

In the field of orofacial surgery, a red blood cell transfusion (RBCT) is occasionally required during double jaw and oral cancer surgery. However, the question remains whether the effect of RBCT during the perioperative period is beneficial or harmful. The answer to this question remains challenging. In the field of orofacial surgery, transfusion is performed for the purpose of oxygen transfer to hypoxic tissues and plasma volume expansion when there is bleeding. However, there are various risks, such as infectious complications (viral and bacterial), transfusion-related acute lung injury, ABO and non-ABO associated hemolytic transfusion reactions, febrile non-hemolytic transfusion reactions, transfusion associated graft-versus-host disease, transfusion associated circulatory overload, and hypersensitivity transfusion reaction including anaphylaxis and transfusion-related immune-modulation. Many studies and guidelines have suggested RBCT is considered when hemoglobin levels recorded are 7 g/dL for general patients and 8-9 g/dL for patients with cardiovascular disease or hemodynamically unstable patients. However, RBCT is occasionally an essential treatment during surgeries and it is often required in emergency cases. We need to comprehensively consider postoperative bleeding, different clinical situations, the level of intra- and postoperative patient monitoring, and various problems that may arise from a transfusion, in the perspective of patient safety. Since orofacial surgery has an especially high risk of bleeding due to the complex structures involved and the extensive vascular distribution, measures to prevent bleeding should be taken and the conditions for a transfusion should be optimized and appropriate in order to promote patient safety.