Transfusion-associated cytomegalovirus infections in seropositive cardiac surgery patients

Incidence of Cytomegalovirus Primary and Secondary Infection in Adolescent Girls: Results From a Prospective Study

Developing a vaccine to prevent congenital cytomegalovirus (CMV) infection and newborn disability requires an understanding of infection incidence. In a prospective cohort study of 363 adolescent girls (NCT01691820), CMV serostatus, primary infection, and secondary infection were determined in blood and urine samples collected at enrollment and every 4 months for 3 years. Baseline CMV seroprevalence was 58%. Primary infection occurred in 14.8% of seronegative girls. Among seropositive girls, 5.9% had ≥4-fold increase in anti-CMV antibody, and 23.9% shed CMV DNA in urine. Our findings provide insights on infection epidemiology and highlight the need for more standardized markers of secondary infection.

Are children with protein-losing enteropathy after the Fontan operation at increased risk of cytomegalovirus enteropathy? A report of two cases

INTRODUCTION

Aetiology of protein-losing enteropathy in single-ventricle type CHD is multi-factorial.

REPORT

We describe two Fontan patients with protein-losing enteropathy who presented with cytomegalovirus-associated colitis.

DISCUSSION

Fontan patients display risk factors for cytomegalovirus-induced gastroenteropathy that may affect lymph angiogenesis, disease development, and progression.

CONCLUSION

Cytomegalovirus enteropathy may be common among Fontan patients who suffer from protein-losing enteropathy. Polymerase chain reaction is important for detection.

Clinical presentation and risk factors for cytomegalovirus colitis in immunocompetent adult patients

BACKGROUND

Cytomegalovirus (CMV) colitis is a common manifestation of CMV end-organ disease, which has typically been described in immunocompromised hosts. Recently, it has been noted that this also occurs in immunocompetent patients. To gather relevant data about clinical presentation, prognosis, and risk factors for development of CMV colitis in immunocompetent hosts, we analyzed all cases that occurred during a 19-year period at our institution.

METHODS

A case-control study was performed to identify risk factors for CMV colitis in immunocompetent hosts. Electronic medical records of individuals who were admitted and diagnosed with CMV colitis between January 1995 and February 2014 at a tertiary care university hospital were reviewed. Two non-CMV colitis patients who were age- and sex-matched were selected as controls for each case.

RESULTS

A total of 51 patients with CMV colitis were included in this study along with 102 control patients. Certain conditions including renal disease on hemodialysis, neurologic disease, rheumatologic disease, intensive care unit admission, and exposure to antibiotics, antacids, steroids, or red blood cell (RBC) transfusions within 1 month of diagnosis of colitis were associated with CMV colitis on univariate analysis. Among these, steroid use and RBC transfusion within 1 month were identified as independent risk factors for developing CMV colitis on multivariate analysis. The 30-day mortality rate was 7.8% without any attributable mortality.

CONCLUSIONS

Steroid use and RBC transfusion within 1 month of the diagnosis of colitis were independent risk factors for development of CMV colitis in immunocompetent hosts.

Resistant pathogens, fungi, and viruses

Although originally described in Staphylococcus aureus, resistance among bacteria has now become a race to determine which classes of bacteria will become more resistant. Availability of antibacterial agents has allowed the development of entirely new diseases caused by nonbacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. This article presents the growing body of knowledge of the herpes family of viruses, and their occurrence and consequences in patients with concomitant surgical disease or critical illness. The focus is on previously immunocompetent patients, as the impact of herpes viruses in immunosuppressed patients has received thorough coverage elsewhere.

Cytomegalovirus reactivation in critically ill immunocompetent hosts: a decade of progress and remaining challenges

Human cytomegalovirus (HCMV) is an undisputed pathogen in humans with severe immune compromise, which has historically been thought to carry little consequence in immunocompetent hosts. During the past decade, however, accumulating data suggest that significant numbers of immunocompetent humans reactivate HCMV during critical illness, and that these reactivation episodes are associated with worsened outcomes. Because most people are infected with this ubiquitous virus by adulthood, confirming pathogenicity has now become a clinical priority. In this article, we will review the incidence and implications of reactivation, the relevant immune responses and reactivation triggers relevant to the immunocompetent host. We will summarize the progress made during the past ten years, outline the work ongoing in this field, and identify the major gaps remaining in our emerging understanding of this phenomenon.

Transfusion-Transmitted Cytomegalovirus: Lessons From a Murine Model

Transfusion-transmitted cytomegalovirus (CMV) infection (TT-CMV) continues to complicate blood transfusion therapy, which can lead to severe morbidity or mortality in immunocompromised or immuno-immature recipients. The biological mechanisms that underlie TT-CMV (eg, viral latency in donor monocytes or stimulatory signals in the transfusion recipient leading to cytomegalovirus reactivation) are difficult to study in humans, but can be addressed in animal models. In this review, we discuss a mouse blood transfusion model, which can be used to investigate these issues as well as to validate methods to prevent TT-CMV in at-risk patients.

Risks of blood transfusion

This article discusses advances in blood safety during the last 20 years, particularly for prevention of transfusion-transmitted viral infections. Although the most serious known risks from blood transfusion are administrative errors, transfusion-related acute lung injury, and bacterial contamination in platelet products, infection from emerging pathogens such as West Nile virus emphasizes the need for implementing proactive strategies. Pathogen inactivation technologies and reactive strategies such as nucleic acid testing ensure continued advances in blood safety.

Risks of blood transfusion

OBJECTIVE

To review the current status of risks of blood transfusion.

DATA SOURCES, EXTRACTIONS, AND SYNTHESIS

English-speaking literature, literature search using key works, human data, and follow-up with key bibliographic citations.

CONCLUSIONS

Substantial advances have been achieved in blood safety during the last 20 yrs, particularly for transfusion-transmitted viral infections. Currently, the most serious known risks from blood transfusion are administrative error (leading to ABO-incompatible blood transfusion), transfusion-related acute lung injury, and bacterial contamination in platelet products. Emerging pathogens, such as West Nile virus infection emphasize the need for implementation of proactive strategies, such as pathogen inactivation technologies, as well as reactive strategies, such as nucleic acid testing, to ensure continued advances in blood safety.

Absence of activation of CMV by blood transfusion to HIV-infected, CMV-seropositive patients

BACKGROUND

The Viral Activation Transfusion Study (VATS) afforded an opportunity to determine whether blood transfusions, and in particular exogenous WBCs, "activate" CMV replication in HIV-infected, CMV-seropositive patients, and whether such patients can be superinfected by additional strains of CMV transmitted via blood transfusions.

STUDY DESIGN AND METHODS

A total of 531 patients were randomized to receive either WBC-reduced (WBCR) or non-WBC-reduced (NWBCR) RBC units. Plasma CMV PCR assays were performed before transfusion and weekly after transfusion for 4 weeks. NWBCR cases with evidence of possible reactivation and/or superinfection were further studied for donor viremia by DNA PCR of frozen retention segments and new genotype acquisition using gB envelope sequence analysis of pre- and posttransfusion recipient specimens.

RESULTS

VATS patients received a median of two RBC units during their initial transfusion. Whether positive or negative for CMV DNA at baseline, there were no significant treatment-arm differences in the percentage of patients who had positive qualitative CMV PCR or increases in CMV viral load at follow-up. Of 50 recipients randomized to NWBCR RBC and meeting criteria for possible CMV superinfection, 25 had sufficient CMV DNA load in a baseline and one or more viremic follow-up sample to permit comparison of gB genotypes. Only two recipients showed genotype shifts. Of 125 WBC pellets prepared from the seropositive units transfused into these 50 cases, only 1 tested weakly PCR positive for CMV DNA (insufficient copy number for genotyping).

CONCLUSION

There was no evidence of "activation" of CMV by blood transfusion. Among the NWBCR RBC recipients, there was little evidence of possible transmission of new CMV strains. Hence, the current policy for transfusion support of HIV-infected patients, which allows transfusion of CMV-antibody-positive blood to CMV-seropositive patients, is appropriate.

Occult herpes family viral infections are endemic in critically ill surgical patients

OBJECTIVE

Herpes family viruses have been recognized as pathogens for many years in immunosuppressed transplant or human immunodeficiency virus patients, but they have garnered little attention as potential pathogens in the nonimmunosuppressed critically ill. The objective of this study was to define the prevalence of and risk factors for development of herpes family virus infection in chronic critically ill surgical patients.

DESIGN

Prospective epidemiologic study.

SETTING

A 38-bed surgical intensive care unit in a major university hospital.

PATIENTS

Nonimmunosuppressed intensive care unit patients in intensive care unit for >/=5 days.

INTERVENTIONS

None; patients received no antiviral treatment during the study.

MEASUREMENTS AND MAIN RESULTS

Weekly cultures for cytomegalovirus (CMV) and herpes simplex virus, viral serologies, and T-cell counts were performed. The prevalence (95% confidence interval) of positive respiratory cultures for herpes simplex or CMV was 35% (22-49%); 15% (5-25%) cultured positive for CMV, 23% (11-35%) cultured positive for herpes simplex virus, and one patient's respiratory secretions culturing positive for both CMV and herpes simplex virus. The prevalence of CMV viremia was only 5.8% (1-10%). CMV+ patients had longer hospital admissions, intensive care unit admissions, and periods of ventilator dependence than CMV- patients, despite having comparable severity of illness scores. CMV+ patients also had significantly higher numbers of blood transfusions, prevalence of steroid exposure, and prevalence of hepatic dysfunction, and all were immunoglobulin G positive at the beginning of the study. In contrast, herpes simplex virus-positive patients had lengths of hospital admissions, lengths of intensive care unit admissions, and periods of ventilator dependence comparable with patients without viral infections (p >.05).

CONCLUSIONS

There is a significant prevalence (22-49%) of occult active herpes family viruses in chronic critically ill surgical patients. The clinical significance of these viral infections is unknown, although CMV+ patients have significantly higher morbidity rates than CMV- patients. Several factors suggest pathogenicity, but further study is needed to define causality.

CMV and blood transfusions

Among the human herpesviruses, cytomegalovirus (CMV) is the only one that has assumed significant importance in blood transfusion. Transfusion transmission of CMV (TT-CMV) to seronegative immunocompromised patients can lead to lethal CMV disease. Studies over the past 30 years have demonstrated that monocytes latently infected with CMV represent the primary vector for TT-CMV, and that TT-CMV can be largely abrogated by transfusing at-risk patients with either seronegative units or blood filtered to remove white blood cells. However, the small number of cases of breakthrough TT-CMV that follow transfusion of either seronegative or filtered blood still produce morbidity and mortality. These circumstances have motivated ongoing efforts to provide improved protection from TT-CMV, including the use of CMV DNA amplification for blood screening, and pathogen inactivation to sterilise all blood components prior to transfusion.

Human cytomegalovirus infections in nonimmunosuppressed critically ill patients

OBJECTIVE

To assess the occurrence of active human cytomegalovirus (HCMV) infection and HCMV disease and to evaluate potential risk factors in immunocompetent intensive care patients after major surgery or trauma.

DESIGN

A prospective clinical study.

SETTING

An anesthesiological intensive care unit (ICU) in a university hospital.

PATIENTS

Fifty-six anti-HCMV immunoglobulin G (IgG) seropositive patients without manifest immunodeficiency whose simplified acute physiology score (SAPS II) value rose to >or=41 points during their ICU stay.

INTERVENTIONS

Once a week, the patients were examined for active HCMV infection by polymerase chain reaction and by viral cultures from blood and lower respiratory tract secretions. Three times a week, detailed clinical examination for signs of HCMV disease was carried out.

MEASUREMENTS AND MAIN RESULTS

Twenty of the 56 ICU patients (35.6%) who met the study criteria of a SAPS II score >40 points and anti-HCMV IgG seropositivity developed an active HCMV infection as diagnosed by the detection of HCMV DNA in leukocytes, plasma, or respiratory tract secretions. In seven patients, the virus was isolated in the respiratory tract secretions. Severe HCMV disease appeared in two patients with pneumonia or encephalitis respectively. In patients with active HCMV infection, the mortality tended to be higher (55%) than in those without (36%); the duration of intensive care treatment of the survivors was significantly longer in the patients with active HCMV infection (median 30 vs. 23 days; p = .0375). Univariate testing for factors associated with active HCMV infection showed the importance of sepsis at admission (p = .011) and prolonged pretreatment on the ward or in an external ICU (p = .002); the relevance of underlying malignant disease was borderline (p = .059). Multiple regression analysis identified only sepsis to be independently associated with active HCMV infection (p = .02; odds ratio, 4.62).

CONCLUSIONS

Even in a group of ICU patients without manifest immunodeficit who were anti-HCMV IgG seropositive and had reached a SAPS II score of >or=41 points, active HCMV infection occurred frequently (35.6%). Septic patients were affected twice as often as the total study population. In 2 of the 20 cases, active HCMV infection progressed to severe HCMV disease. Proper diagnosis demands special clinical attention combined with extended virological examinations. Further studies in a larger patient group should evaluate the influence of HCMV on ICU mortality.

Intraoperative hypothermia is an independent risk factor for early cytomegalovirus infection in liver transplant recipients

BACKGROUND

Early cytomegalovirus (CMV) reactivation infections have been found to be associated with a number of stress responses such as severe bacterial infection. Intraoperative hypothermia is known to be a significant physiological stressor. Hence, we sought to evaluate a relationship between intraoperative hypothermia during liver transplantation and early CMV infection.

METHODS

Relationships between intraoperative hypothermia and early CMV infection were assessed using univariate and multivariate analysis.

RESULTS

There were 11 of 100 patients who had CMV infection detected within the first 30 days after the transplant and 16 of 100 in the next 3 months after the transplant. The median intraoperative temperature (34.4 degrees C) of those who subsequently developed early CMV infection was significantly lower than that in patients who did not develop early CMV infection (35.3 degrees C; P = 0.032). Multivariate analysis showed that only hypothermia was an independent predictor of early CMV infection (odds ratio 2.8, 95% confidence intervals 1.2-6.4; P = 0.047).

CONCLUSIONS

Intraoperative hypothermia during liver transplantation increases the risk of CMV infection in the 1st month postoperatively and active warming seems to reduce this risk.

Evaluation by polymerase chain reaction of cytomegalovirus reactivation in intensive care patients under mechanical ventilation

OBJECTIVE

The study was undertaken to determine if critically ill patients under mechanical ventilation could reactivate latent cytomegalovirus (CMV) in either lung or blood.

DESIGN

Prospective study in critically ill patients was performed in a multidisciplinary intensive care unit in a university hospital.

PATIENTS

23 non-immunocompromised, mechanically ventilated patients who were anti-CMV immunoglobulin G-positive. Ten immunocompromised patients with active CMV infection and 16 asymptomatic CMV seropositive non-immunocompromised patients constituted the positive and negative control groups.

MEASUREMENTS AND RESULTS

The presence of CMV in blood and bronchoalveolar lavage (BAL) was evaluated by both viral cultures and polymerase chain reaction (PCR). Thirty-seven blood and 22 BAL samples were investigated. Sequential samples were evaluated in 8 patients. For PCR, a 290 bp fragment in the first exon of the immediate early 1 gene was amplified. In order to exclude inhibitors of PCR amplification, a 268 bp fragment of the beta-globin gene was concurrently amplified in all samples. Viral cultures of blood and BAL were negative in all 23 non-immunocompromised, mechanically ventilated patients. Moreover, no CMV DNA could be amplified in blood BAL samples, whereas a beta-globin amplification was observed in all samples.

CONCLUSION

In a series of 23 critically ill patients under mechanical ventilation who were seropositive for CMV, no reactivation of CMV in blood or lung was demonstrated.

[Epidemiological support in blood surveillance]

"Hémovigilance" is a continuous and standardized system for data collection and analysis, and diffusion of results to clinical and public health decision makers. This system has different objectives than clinical and epidemiological research on labile blood products. A published study of characteristics of donors that are infected by the human immunodeficiency virus illustrates the need for information on temporal patterns of events relevant to transfusion safety. Two cohort studies on post-transfusion hepatitis and a randomized study on cytomegalovirus infections illustrate the importance of surveillance for detecting events that are causally linked to transfusion. The interest of "hémovigilance" is also discussed in the context of epidemics and new hazards, when surveillance is the only possibility of designing ad-hoc epidemiologic studies, yielding results within delays compatible with decisions that are timely and effective for improving transfusion safety.

Intraoperative blood salvage

Interest in and use of IBS have increased recently. This form of haemotherapy involves the retrieval of blood shed perioperatively. IBS, together with other forms of ABT, has gained a prominent role in transfusion medicine, largely due to an increased awareness of the risks associated with transfusion of homologous blood. In addition to conserving erythrocytes, IBS prevents disease transmission, other adverse transfusion reactions, and alloimmunization to antigens in blood cells and plasma which may result from homologous blood use. An array of IBS devices is presently available, ranging from disposable canisters to complete processing systems. The devices are capable of recovering, filtering, washing and reinfusing shed erythrocytes. They can be divided into slow-flow and rapid-flow systems based on the rapidity of blood processing. Most systems use a dual channel aspiration cannula through which shed blood is aspirated and mixed with anticoagulant solution. The salvage procedure requires operator control at every step, even for the highly automated instruments. Various health care personnel have been trained to operate IBS equipment; a transfusion service nurse with blood bank expertise has proved to be a highly reliable operator in our practice. Extensive clinical observation has shown that salvaged erythrocytes function and survive normally. IBS has been applied in many surgical fields; it has two relative contraindications: its use in areas affected by infection or malignancy. Operative procedures characterized by large blood losses provide a cost-efficient application of IBS, including cardiac surgery, orthopaedic procedures, trauma, vascular surgery, and liver transplantation. New, highly efficient technology is emerging that is capable of recovering other blood components. Consequently, what presently amounts to erythrocyte recovery will be expanded shortly to include platelets and plasma, with its many constituents.

Incidence and morbidity of cytomegaloviral infection in patients with mediastinitis following cardiac surgery

To determine the incidence and morbidity of infections with CMV associated with mediastinitis after conventional cardiac surgery, 115 consecutive adult patients with mediastinitis were evaluated with viral cultures of blood and urine. Shedding of CMV was seen in 29 patients (25 percent) within a mean period of 37 +/- 22 days after cardiopulmonary bypass. Viremia was documented in 79 percent (23) of these 29 patients. Acute renal failure and enzymatic abnormalities (AST and LDH) were significantly more common in patients with virologically proven infection with CMV (p less than 0.05). In patients who survived the initial period of bacterial infection, major differences in their clinical course were observed according to their virologic status. After the 15th day of hospitalization following the débridement, the persistence of local infection was more frequent (p less than 0.05) and the mortality was higher (p less than 0.01) in CMV-infected patients. Moreover, the mean duration of hospitalization in the ICU for survivors was 69 +/- 36 days in viral shedders, compared with 48 +/- 27 days in nonshedders (p less than 0.05). Infection with CMV in mediastinitis occurs frequently and is associated with persistence of local infection, prolonged hospitalization, and increased late mortality.

[Liver transplantation in adults: postoperative management and development during the first months]

Recent improvements in the results of orthotopic liver transplantation (OLT) have made this a well-accepted treatment for patients with severe hepatic failure. Current problems encountered following OLT are discussed. Immediate complications comprise surgical bleeding, primary graft non-function, and graft failure due to hepatic artery occlusion. Secondary complications are frequent. Surgical ones include biliary and vascular (hepatic artery thrombosis most often) problems, as well as intra-abdominal abscesses associated with gastrointestinal perforation, biliary leak, graft ischaemia or an infected haematoma. 40% of patients having undergone OLT will be reoperated on, 2/3 of them within 3 months. Non-surgical complications are mostly pulmonary. The risk of pneumonitis is increased by prolonged mechanical ventilation; it is always potentially disastrous in the immunosuppressed, transplanted patient. Hypertension is also often seen in the early postoperative period; it requires prompt treatment. Early renal impairment after OLT is common, and of better prognosis than late onset renal failure, which is generally associated with shock, graft failure, sepsis or use of nephrotoxic agents. Seizures, usually only one, occur in about 10% of patients; recovery is complete. Encephalopathy with intracranial oedema related to fulminant hepatitis has a worse prognosis, but survival figures are quite encouraging. Three type of rejection are described after OLT: 1) severe accelerated rejection (very rare), 2) acute rejection encountered in about 70% of patients over the first 3 months, and 3) late rejection, which can lead to the vanishing bile duct syndrome (VBDS). Diagnosis of rejection is made by liver biopsy. Prophylactic immunosuppression includes cyclosporin, methylprednisolone and azathioprine. Cyclosporin toxicity and drug interactions are reviewed. Treatment of acute rejection episodes comprises an initial bolus of high doses of corticoid drugs; if there is no response, antilymphocyte globulin or monoclonal antibodies may have to be used. Infection is the main cause of death following OLT. Early infections, mostly intra-abdominal and pulmonary, are bacterial or fungal. Vital (especially CMV) and other opportunistic infections occur generally after the second week. Retransplantation, carried out in 10 to 25% of patients, may be urgent in case of primary graft failure, or hepatic artery thrombosis associated with graft failure, or hepatic artery thrombosis associated with graft failure. Other indications are early graft rejection with severe hepatic dysfunction, chronic rejection with severe VBDS, and recurrence of the initial disease.

Infectious complications of blood transfusion

Numerous infectious diseases are transmissible by blood, with AIDS and hepatitis being the predominant concerns today. Less in the limelight, but nonetheless blood transmissible, are cytomegalovirus infection, malaria, babesiosis, and hepatitis B. A major controversy with respect to non-A non-B hepatitis relates to the use of 'surrogate' testing of donors for ALT and hepatitis B core antibody. Transfusion-associated AIDS has been markedly reduced as a risk, due to blood donor antibody screening implemented in March 1985. However, other retroviruses such as HTLV-1, HTLV-II and HIV-II pose additional concerns regarding the safety of the blood supply, and decisions will be forthcoming regarding testing of donated blood for antibody to these viruses.

Cytomegalovirus and blood transfusion

The problem of transfusion-transmitted cytomegalovirus (CMV) infection differs from that for other transfusion-transmitted infections in that only patients who are immunocompromised require CMV-free blood or components. The virus is cell-associated and transmission appears to be due to reactivation of latent virus in white blood cells. As a herpes virus, CMV can be responsible for primary infections, reactivations or reinfections in humans. The use of restriction endonuclease techniques is sometimes necessary to pinpoint the origin of infections. Serological studies have shown that CMV infection is worldwide, but seropositivity rates vary widely being highest in underdeveloped countries, rising both with age and lower socio-economic status. Provision of CMV seronegative blood therefore involves considerable administrative as well as laboratory effort and planning, especially if panels of previously tested, seronegative donors are organized. Serious complications of transfusion-transmitted CMV infection (which can occasionally prove fatal) are only seen with immuno-suppressed patients (commonly low birth weight infants or transplant recipients). Prevention or amelioration of CMV infection with appropriate patients can be attempted by reducing the number of white blood cells present in blood or components by filtration or washing, administration of CMV immune globulin or provision of blood found by serological screening to be CMV-seronegative.

The clinical importance of leukocyte depletion in regular erythrocyte transfusions

Antilymphocyte, antigranulocyte and antiplatelet alloantibodies, T lymphocyte subsets, expression of HLA-DR antigens on T lymphocytes and NK cell function were determined in 11 homozygous beta-thalassemic children multitransfused ab initio with Erypur-filtered leukocyte-free red cell units (group A) and in 13 similar children multitransfused with standard packed red cell units (group B). No antibodies were found in group A patients, whereas 69% of group B patients were immunized. The two groups did not differ significantly with regard to the other test results. Considered together, thalassemia patients showed a percentage of T4+ cells and a NK cell function that were significantly lower than those found in a reference group of 16 healthy male blood donors. Thalassemics moreover showed a higher than normal percentage of T3+, T4+ and T8+ cells expressing HLA-DR antigens. The results indicate that leukocyte-free red cells should be the treatment of choice for prospective recipients of multiple transfusions, since they are capable of preventing (or delaying) the production of alloantibodies against leukocytes and platelets. From the data of the present study, it does not seem that the transfusion of leukocyte-free red cells is capable of preventing the abnormalities of some immunological tests that occur in some multitransfused patients. Further investigations, however, are needed to draw conclusions on this problem.

Development of CMV antibody tests and their clinical evaluation

An anti-CMV ELISA was developed in which monoclonal antibodies to immobilize the CMV antigens are used. The test was compared with the IHA test and there was 98.6% agreement. Using the CF test as a referee, sensitivity and specificity of the ELISA were calculated to be 98.6 and 99.0%, respectively. The seroconversion rate among Dutch donors was estimated from the age-related prevalence of anti-CMV antibodies to be about 0.4%. Specific anti-CMV IgM was searched for in a large donor population using an antibody-capture IgM ELISA; 1 of 600 donor sera was found positive. This makes it unlikely that screening for IgM anti-CMV will effectively prevent posttransfusion CMV infections. In order to meet the demand for simpler tests, a one-step ELISA was recently developed, based on the inhibition principle. Preliminary studies with this test indicate a high sensitivity and specificity.

Transfusion-transmitted cytomegalovirus infections: significance and control

Cytomegalovirus (CMV) is a herpes virus which can give rise to primary infections, reactivated infections, or reinfections in humans. Seroepidemiologic studies have shown CMV infection to be worldwide with the highest antibody prevalences detected in Third World countries; however, significant regional variations can be seen within a given country. Antibody prevalence varies directly with age and inversely according to socioeconomic status. Numerous prospective studies of blood transfusion recipients carried out since 1966 have shown marked differences in infection rates but relatively little associated disease. Infection rates were highest in seronegative recipients given large amounts of fresh blood. Recently published reports have shown substantially lower infection rates than earlier studies, a change likely to be due to the current practice of transfusing fewer units of older blood. CMV has not been found to play a significant role in the etiology of posttransfusion hepatitis. CMV infections have been found to be an important source of morbidity and mortality in immunocompromised patients. Several studies of transfused, premature infants have shown significant differences in infection rates and disease expression. Seronegative low-birth-weight infants receiving blood from seropositive donors are at greatest risk. Blood from CMV-seronegative donors substantially lowers the risk of infection. Receiving a kidney or heart from a CMV-seropositive donor appears to be a more salient risk factor than blood transfusion in renal and cardiac transplant patients who are also more likely to have symptomatic CMV infections. Leukocyte transfusions have been found to be a significant source of CMV infection and disease in bone marrow transplant patients.(ABSTRACT TRUNCATED AT 250 WORDS)