Evan M. Bloch

Zika Virus and the Blood Supply: What Do We Know?

Zika virus (ZIKV), a mosquito-borne Flavivirus and emerging infectious disease, is the focus of an international public health emergency after its rapid spread through the Americas and the Caribbean. Although most ZIKV infections are subclinical or characterized by mild febrile illness, ZIKV has been implicated in severe complications, most notably microcephaly in babies born to incident infected mothers during pregnancy. As yet, the extent to which ZIKV is transfusion transmissible remains undefined. Nonetheless, a high prevalence of asymptomatic infection during outbreaks, the demonstration of ZIKV in blood donors, and 4 possible cases of transfusion-transmitted ZIKV in Brazil have raised concern for risk to the blood supply. Consequently, a proactive response is underway by blood collection agencies, regulatory bodies, national funding agencies, and industry alike. Mitigation strategies differ between endemic and nonendemic areas. In the continental United States, the American Association of Blood Banks and Food and Drug Administration guidelines recommend travel-based deferral for those returning from affected areas, and nucleic acid testing is being initiated under an investigational new drug application in Puerto Rico and selected areas of the United States. Options are less clear for countries where autochthonous vector-borne transmission is active. The burden of Zika falls in low-resource countries where high cost and technical barriers associated with testing and pathogen reduction pose barriers to implementation. Additional strategies include maintaining selective inventory for high-risk recipients (eg, pregnant women). We review the available data as of July 2016 on ZIKV in relation to the blood supply including risk, mitigation strategies, and barriers to implementation in addition to the research that is needed to address current uncertainty.

Medical and economic implications of strategies to prevent alloimmunization in sickle cell disease

The pathogenesis of alloimmunization is not well understood, and initiatives that aim to reduce the incidence of alloimmunization are generally expensive and either ineffective or unproven. In this review, we summarize the current medical literature regarding alloimmunization in the sickle cell disease (SCD) population, with a special focus on the financial implications of different approaches to prevent alloimmunization.

A rare, potentially life‐threatening presentation of passenger lymphocyte syndrome

Passenger lymphocyte syndrome occurs when donor lymphocytes are transplanted with a solid organ and produce alloantibodies that react with antigens on the recipients red blood cells (RBCs). Typically, passenger lymphocyte syndrome presents as immunoglobulin G antibody‐mediated, extravascular hemolytic anemia with reticulocytosis. Often, the donor was alloimmunized before transplantation.

The contribution of unsafe blood transfusion to human immunodeficiency virus incidence in sub-Saharan Africa: reexamination of the 5% to 10% convention

Historical estimates have attributed 5% to 10% of new human immunodeficiency virus (HIV) infections in sub‐Saharan Africa (SSA) to unsafe blood transfusions. Although frequently cited, the validity of this statistic is uncertain or outdated. Recent estimates suggest blood transfusions contribution to new HIV infections in the region may be much lower.

Funding blood safety in the 21st century

Since 2000, there has been an historic increase in international development assistance, including blood safety projects. The result has been increased blood donations and infectious disease screening in many beneficiary countries. A comprehensive examination of international development assistance for blood safety has yet to be completed.

Genomic Epidemiology Reconstructs the Introduction and Spread of Zika Virus in Central America and Mexico

Summary The Zika virus (ZIKV) epidemic in the Americas established ZIKV as a major public health threat and uncovered its association with severe diseases, including microcephaly. However, genetic epidemiology in some at-risk regions, particularly Central America and Mexico, remains limited. We report 61 ZIKV genomes from this region, generated using metagenomic sequencing with ZIKV-specific enrichment, and combine phylogenetic, epidemiological, and environmental data to reconstruct ZIKV transmission. These analyses revealed multiple independent ZIKV introductions to Central America and Mexico. One introduction, likely from Brazil via Honduras, led to most infections and the undetected spread of ZIKV through the region from late 2014. Multiple lines of evidence indicate biannual peaks of ZIKV transmission in the region, likely driven by varying local environmental conditions for mosquito vectors and herd immunity. The spatial and temporal heterogeneity of ZIKV transmission in Central America and Mexico challenges arbovirus surveillance and disease control measures.

How do we manage blood donors and recipients after a positive Zika screening result

Zika virus (ZIKV) is a mosquito‐borne flavivirus that is the focus of an ongoing pandemic. ZIKV is notable for its severe neurologic sequelae in babies born to infected mothers. High rates of subclinical infection, as evidenced by the finding of ZIKV RNA in asymptomatic donors, raise concerns of risk to the blood supply. To date, a total of four suspected cases of transfusion‐transmitted ZIKV have been reported (all in Brazil), none of which were associated with clinical infection in the transfusion recipients. In 2016, the US Food and Drug Administration issued a guidance mandating national blood donor screening for ZIKV in the United States. Five days after implementation of donor screening at our facility, we encountered a ZIKV‐positive donor. We provide a practical approach to donor, recipient, and blood product management in the setting of a positive donor ZIKV result. Such has been informed by the challenges we faced in the workup of a ZIKV‐reactive donation and recipient lookback.

Blood Product Utilization Among Trauma and Nontrauma Massive Transfusion Protocols at an Urban Academic Medical Center

BACKGROUND: Hospital-wide massive transfusion protocols (MTPs) primarily designed for trauma patients may lead to excess blood products being prepared for nontrauma patients. This study characterized blood product utilization among distinct trauma and nontrauma MTPs at a large, urban academic medical center. METHODS: A retrospective study of blood product utilization was conducted in patients who required an MTP activation between January 2011 and December 2015 at an urban academic medical center. Trauma MTP containers included 6 red blood cell (RBC) units, 5 plasma units, and 1 unit of apheresis platelets. Nontrauma MTP containers included 6 RBC and 3 plasma units. RESULTS: There were 334 trauma MTP activations, 233 nontrauma MTP activations, and 77 nontrauma MTP activations that subsequently switched to a trauma MTP (“switched activations”). All nontrauma MTP activations were among bleeding patients who did not have a traumatic injury (100% [233/233]). Few patients with a nontrauma activation required ad hoc transfusion of RBC units (1.3% [95% confidence interval {CI}, 0.3%–3.7%]) or plasma (3.4% [95% CI, 1.5%–6.7%]), and only 45.5% (95% CI, 39.0%–52.1%) required ad hoc transfusion of apheresis platelets. Compared to trauma and switched activations, nontrauma activations transfused a lower median number of RBC, plasma, and apheresis platelet units (P < .001 for all comparisons). There was also a lower median number of prepared but unused plasma units for nontrauma activations (3; [interquartile range {IQR}, 3–5]) compared to trauma (7; [IQR, 5–10]; P < .001) and switched activations (8; [IQR, 5–11]; P < .001). The median number of unused apheresis platelet units was 1 (IQR, 1–2) for trauma activations and 0 (IQR, 0–1) for switched activations. There was a high proportion of trauma and switched activations in which all of the prepared apheresis platelet units were unused (28.1% [95% CI, 23.4%–33.3%] and 9.1% [95% CI, 3.7%–17.8%], respectively). CONCLUSIONS: The majority of initial nontrauma MTP activations did not require a switch to a trauma MTP. Patients remaining under a nontrauma MTP activation were associated with a lower number of transfused and unused plasma and apheresis platelet units. Future studies evaluating the use of hospital-wide nontrauma MTPs are warranted since an MTP designed for nontrauma patient populations may yield a key strategy to optimize blood product utilization in comparison to a universal MTP for both trauma and nontrauma patients.

Antibiotic resistance in young children in kilosa district, Tanzania 4 years after mass distribution of azithromycin for trachoma control

Mass administration of azithromycin (MDA) is integral to trachoma control. Recent studies suggest that MDA may increase drug-resistant pathogens, yet findings from prior studies suggest little long-term impact on resistance. This disparity may be linked to differences in pre-MDA community-level resistance patterns. We describe carriage prevalence and antibiotic resistance patterns for Streptococcus pneumoniae (Spn) (nasopharyngeal swab collection), Staphylococcus aureus (SA) (nasopharyngeal swabs), and Escherichia coli (EC) (rectal swabs) in 1,047 children ages 1-59 months in a district with MDA cessation 4 years ago. Antibiotic susceptibility was evaluated by disk diffusion and Etest. The carriage rates for Spn, SA, and EC were 43.5% (455/1,047), 13.2% (138/1,047), and 61.7% (646/1,047), respectively. Resistance to AZM was observed in 14.3%, 29.0%, and 16.6% of the Spn, SA, and EC isolates, respectively. Spn resistance was variable (0-67%) by hamlet. Future analyses will assess the influence of pre-MDA antibiotic resistance patterns on those observed following MDA.

Overview of Infectious Disease Testing

Abstract Safe and available blood products are required for optimal functioning of any advanced medical system. Indeed, ensuring blood product safety relies on the timely recognition of emerging transfusion-transmissible pathogens, selection of low-risk blood donors, robust donor screening using risk-based deferral as well as laboratory testing for infectious disease markers, and the application of good manufacturing practices, rigorous quality, accreditation, and inspection systems. The focus of this chapter is on laboratory-based infectious disease testing of whole blood and apheresis-derived allogeneic donation in the United States. Practices are similar in other high-income countries, although national requirements and regulatory bodies differ. Infectious disease testing in low-income countries is challenging, as limited fiscal resources, technical expertise, and infrastructure impose limitations on both the scope and the quality of testing.