Patient and immunological factors associated with delayed clearance of mucosal SARS-CoV-2 RNA and symptom persistence.

Serial blood and mucosal samples were characterized for 102 participants enrolled a median of 7.0 days post-COVID-19 diagnosis. Mucosal RNA was detectable a median 31.5 (95% CI 20.5 - 63.5) days, with persistence ≥1 month associated with obesity (BMI ≥30, OR 3.9, 95% CI 1.2 - 13.8) but not age, sex, or chronic conditions. Fifteen participants had likely reinfection; lower serum anti-S IgG levels were associated with reinfection risk. Nearly half of participants (47%) reported symptoms lasting ≥2-3 months; persistence ≥3 months was associated with BMI ≥30 (OR = 4.2 95% CI 1.1 - 12.8) and peak anti-S and anti-NC antibody levels.

Prevalence of SARS-CoV-2 Viremia in Presymptomatic Blood Donors in the Delta and Omicron Variant Eras.

Presymptomatic plasma samples from 1596 donors reporting coronavirus disease 2019 infection or symptoms after blood donation were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and anti-S and anti-N antibodies. Prior infection and vaccination both protected from developing SARS-CoV-2 RNAemia and from symptomatic infection. RNAemia rates did not differ in the Delta and Omicron variant eras.

Frequent detection but lack of infectivity of SARS-CoV-2 RNA in presymptomatic, infected blood donor plasma.

Respiratory viruses such as influenza do not typically cause viremia; however, SARS-CoV-2 has been detected in the blood of COVID-19 patients with mild and severe symptoms. Detection of SARS-CoV-2 in blood raises questions about its role in pathogenesis as well as transfusion safety concerns. Blood donor reports of symptoms or a diagnosis of COVID-19 after donation (post-donation information, PDI) preceded or coincided with increased general population COVID-19 mortality. Plasma samples from 2,250 blood donors who reported possible COVID-19-related PDI were tested for the presence of SARS-CoV-2 RNA. Detection of RNAemia peaked at 9%-15% of PDI donors in late 2020 to early 2021 and fell to approximately 4% after implementation of widespread vaccination in the population. RNAemic donors were 1.2- to 1.4-fold more likely to report cough or shortness of breath and 1.8-fold more likely to report change in taste or smell compared with infected donors without detectable RNAemia. No infectious virus was detected in plasma from RNAemic donors; inoculation of permissive cell lines produced less than 0.7-7 plaque-forming units (PFU)/mL and in susceptible mice less than 100 PFU/mL in RNA-positive plasma based on limits of detection in these models. These findings suggest that blood transfusions are highly unlikely to transmit SARS-CoV-2 infection.

Population-Weighted Seroprevalence From Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection, Vaccination, and Hybrid Immunity Among US Blood Donations From January to December 2021.

BACKGROUND: Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, independently and combined ("hybrid immunity"), result in partial protection from subsequent infection and strong protection from severe disease. Proportions of the US population who have been infected, vaccinated, or have hybrid immunity remain unclear, posing a challenge for assessing effective pandemic mitigation strategies. METHODS: In this serial cross-sectional study, nationwide blood donor specimens collected during January-December 2021 were tested for anti-spike and anti-nucleocapsid antibodies, and donor COVID-19 vaccination history of ≥1 dose was collected. Monthly seroprevalence induced from SARS-CoV-2 infection, COVID-19 vaccination, or both, were estimated. Estimates were weighted to account for demographic differences from the general population and were compared temporally and by demographic factors. RESULTS: Overall, 1 123 855 blood samples were assayed. From January to December 2021, the weighted percentage of donations with seropositivity changed as follows: seropositivity due to vaccination without previous infection, increase from 3.5% (95% confidence interval, 3.4%-3.7%) to 64.0%, (63.5%-64.5%); seropositivity due to previous infection without vaccination, decrease from 15.6% (15.2%-16.0%) to 11.7% (11.4%-12.0%); and seropositivity due to hybrid immunity, increase from 0.7% (0.6%-0.7%) to 18.9% (18.5%-19.3%). Combined seroprevalence from infection, vaccination, or both increased from 19.8% (19.3%-20.2%) to 94.5% (93.5%-94.0%). Infection- and vaccination-induced antibody responses varied significantly by age, race-ethnicity, and region, but not by sex. CONCLUSIONS: Our results indicate substantial increases in population humoral immunity from SARS-CoV-2 infection, COVID-19 vaccination, and hybrid immunity during 2021. These findings are important to consider in future COVID-19 studies and long-term pandemic mitigation efforts.

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.

Evaluating the Safety of West Nile Virus Immunity During Congenital Zika Virus Infection in Mice.

Antibody-dependent enhancement (ADE) is a phenomenon that occurs when cross-reactive antibodies generated from a previous flaviviral infection increase the pathogenesis of a related virus. Zika virus (ZIKV) is the most recent flavivirus introduced to the Western Hemisphere and has become a significant public health threat due to the unanticipated impact on the developing fetus. West Nile virus (WNV) is the primary flavivirus that circulates in North America, and we and others have shown that antibodies against WNV are cross-reactive to ZIKV. Thus, there is concern that WNV immunity could increase the risk of severe ZIKV infection, particularly during pregnancy. In this study, we examined the extent to which WNV antibodies could impact ZIKV pathogenesis in a murine pregnancy model. To test this, we passively transferred WNV antibodies into pregnant Stat2-/- mice on E6.5 prior to infection with ZIKV. Evaluation of pregnant dams showed weight loss following ZIKV infection; however, no differences in maternal weights or viral loads in the maternal brain, spleen, or spinal cord were observed in the presence of WNV antibodies. Resorption rates, and other fetal parameters, including fetal and placental size, were similarly unaffected. Further, the presence of WNV antibodies did not significantly alter the viral load or the inflammatory response in the placenta or the fetus in response to ZIKV. Our data suggest that pre-existing WNV immunity may not significantly impact the pathogenesis of ZIKV infection during pregnancy. Our findings are promising for the safety of implementing WNV vaccines in the continental US.

Sex differences in cytokine production following West Nile virus infection: Implications for symptom manifestation.

West Nile virus (WNV) infection outcomes vary among individuals, with most infections resulting in asymptomatic or mild flu-like symptoms. We previously reported an association between early cytokine production and symptom outcome following WNV infection in US blood donors. In this meta-analysis, we found that WNV-infected females reported more symptoms than WNV-infected males, despite similar initial viremia and type I interferon responses. As the infection progressed, males exhibited a protracted cytokine response-marked by sustained CCL2 (MCP-1), CCL11 (eotaxin-1), CXCL10 (IP-10) and IL-15-that was absent in females. Our results suggest that sex differences may be a factor in sustaining WNV immunity.

Dengue Virus Immunity Increases Zika Virus-Induced Damage during Pregnancy.

Zika virus (ZIKV) has recently been associated with birth defects and pregnancy loss after maternal infection. Because dengue virus (DENV) and ZIKV co-circulate, understanding the role of antibody-dependent enhancement in the context of pregnancy is critical. Here, we showed that the presence of DENV-specific antibodies in ZIKV-infected pregnant mice significantly increased placental damage, fetal growth restriction, and fetal resorption. This was associated with enhanced viral replication in the placenta that coincided with an increased frequency of infected trophoblasts. ZIKV-infected human placental tissues also showed increased replication in the presence of DENV antibodies, which was reversed by FcγR blocking antibodies. Furthermore, ZIKV-mediated fetal pathogenesis was enhanced in mice in the presence of a DENV-reactive monoclonal antibody, but not in the presence of the LALA variant, indicating a dependence on FcγR engagement. Our data suggest a possible mechanism for the recent increase in severe pregnancy outcomes after ZIKV infection in DENV-endemic areas.

Blood donor testing for hepatitis B virus in the United States: is there a case for continuation of hepatitis B surface antigen detection?

BACKGROUND: In the United States, blood donor testing for hepatitis B surface antigen (HBsAg) was initiated in the early 1970s. More recently, testing for antibody to hepatitis B core antigen (anti-HBc) and hepatitis B virus (HBV) DNA have been added. The incidence of hepatitis B has been declining. This study reviews the current status of testing and questions the need for continuation of HBsAg testing. STUDY DESIGN AND METHODS: From July 2011 to June 2015, a total of 22.4 million donations were serologically tested for HBsAg and anti-HBc and for HBV-DNA by nucleic acid testing (NAT). All reactive results were evaluated and a subset of donations that were either potential NAT yield (seronegative) or serologically positive but nonreactive by HBV NAT in minipools (MPs) of 16 were further evaluated by individual donation (ID)-NAT. Samples with detectable HBV DNA were defined as actively infected and considered potentially infectious. RESULTS: Routine testing plus supplemental ID-NAT identified 2035 samples representing active infection including 1965 with anti-HBc, 1602 with HBsAg, and 1453 with HBV DNA by MP-NAT, for respective rates per hundred-thousand donations of 9.10, 8.78, 7.16, and 6.50, continuing the downward trend previously observed. There were 29 HBV DNA-yield samples (1:771,389), 35 HBsAg-yield samples (anti-HBc nonreactive), and 404 with occult hepatitis B infection. There were six samples with HBsAg and HBV DNA detectable only by ID-NAT in the absence of anti-HBc; additional testing was consistent with extremely low or negligible levels of DNA. CONCLUSIONS: Point estimates of HBV infection rates among blood donors continue to decline, as do those for incidence and residual risk. Elimination of HBsAg screening would have negligible impact, with a risk less than 1 per 4 million donations.

Investigational Testing for Zika Virus among U.S. Blood Donors.

BACKGROUND: Because of the potential severe clinical consequences of Zika virus (ZIKV) infection, the large numbers of asymptomatic travelers returning from ZIKV-active areas, the detection of ZIKV nucleic acid in blood, and reports of transmission of ZIKV through transfusion, in 2016 the Food and Drug Administration released recommendations for individual-unit nucleic acid testing to minimize the risk of transmission of ZIKV through blood transfusions. METHODS: The American Red Cross implemented investigational screening of donated blood for ZIKV RNA by means of transcription-mediated amplification (TMA). Confirmatory testing of reactive donations involved repeat TMA, TMA testing in exploratory minipools, real-time reverse-transcriptase polymerase chain reaction, IgM serologic testing, and red-cell TMA. Viral loads in plasma and red cells were estimated by means of end-point TMA. The costs of interdicting a donation that was confirmed to be positive were calculated for the 15-month period between June 2016 and September 2017. RESULTS: Of the 4,325,889 donations that were screened, 393,713 (9%) were initially tested in 24,611 minipools, and no reactive donations were found. Of the 3,932,176 donations that were subsequently tested individually, 160 were initially reactive and 9 were confirmed positive (a 1:480,654 confirmed-positive rate overall; positive predictive value, 5.6%; specificity, 99.997%). Six (67%) of the confirmed-positive donations were reactive on repeat TMA, of which 4 were IgM-negative; of these 4, all 3 that could be tested were reactive on minipool TMA. Two confirmed-positive donors had infections that had been transmitted locally (in Florida), 6 had traveled to ZIKV-active areas, and 1 had received an experimental ZIKV vaccine. ZIKV RNA levels in red cells ranged from 40 to 800,000 copies per milliliter and were detected up to 154 days after donation, as compared with 80 days of detection in plasma at levels of 12 to 20,000 copies per milliliter. On the basis of industry-reported costs of testing and the yield of the tests in our study, the cost of identifying 8 mosquito-borne ZIKV infections through individual-unit nucleic acid testing was $5.3 million per ZIKV RNA-positive donation. CONCLUSIONS: Screening of U.S. blood donations for ZIKV by individual-donation TMA was costly and had a low yield. Among the 9 confirmed ZIKV-positive donations, only 4 were IgM-negative; of these donations, all 3 that were tested were reactive on minipool TMA. (Funded by the American Red Cross and Grifols Diagnostic Solutions.).

Tick-Borne Encephalitis Virus Vaccine-Induced Human Antibodies Mediate Negligible Enhancement of Zika Virus Infection InVitro and in a Mouse Model.

Recent reports in the scientific literature have suggested that anti-dengue virus (DENV) and anti-West Nile virus (WNV) immunity exacerbates Zika virus (ZIKV) pathogenesis in vitro and in vivo in mouse models. Large populations of immune individuals exist for a related flavivirus (tick-borne encephalitis virus [TBEV]), due to large-scale vaccination campaigns and endemic circulation throughout most of northern Europe and the southern Russian Federation. As a result, the question of whether anti-TBEV immunity can affect Zika virus pathogenesis is a pertinent one. For this study, we obtained 50 serum samples from individuals vaccinated with the TBEV vaccine FSME-IMMUN (Central European/Neudörfl strain) and evaluated their enhancement capacity in vitro using K562 human myeloid cells expressing CD32 and in vivo using a mouse model of ZIKV pathogenesis. Among the 50 TBEV vaccinee samples evaluated, 29 had detectable reactivity against ZIKV envelope (E) protein by enzyme-linked immunosorbent assay (ELISA), and 36 showed enhancement of ZIKV infection in vitro. A pool of the most highly reacting and enhanced samples resulted in no significant change in the morbidity/mortality of ZIKV disease in immunocompromised Stat2-/- mice. Our results suggest that humoral immunity against TBEV is unlikely to enhance Zika virus pathogenesis in humans. No clinical reports indicating that TBEV vaccinees experiencing enhanced ZIKV disease have been published so far, and though the epidemiological data are sparse, our findings suggest that there is little reason for concern. This study also displays a clear relationship between the phylogenetic distance between two flaviviruses and their capacity for pathogenic enhancement. IMPORTANCE The relationship between serial infections of two different serotypes of dengue virus and more severe disease courses is well-documented in the literature, driven by so-called antibody-dependent enhancement (ADE). Recently, studies have shown the possibility of ADE in cells exposed to anti-DENV human plasma and then infected with ZIKV and also in mouse models of ZIKV pathogenesis after passive transfer of anti-DENV human plasma. In this study, we evaluated the extent to which this phenomenon occurs using sera from individuals immunized against tick-borne encephalitis virus (TBEV). This is highly relevant, since large proportions of the European population are vaccinated against TBEV or otherwise seropositive.

Enhancement of Zika virus pathogenesis by preexisting antiflavivirus immunity.

Zika virus (ZIKV) is spreading rapidly into regions around the world where other flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), are endemic. Antibody-dependent enhancement has been implicated in more severe forms of flavivirus disease, but whether this also applies to ZIKV infection is unclear. Using convalescent plasma from DENV- and WNV-infected individuals, we found substantial enhancement of ZIKV infection in vitro that was mediated through immunoglobulin G engagement of Fcγ receptors. Administration of DENV- or WNV-convalescent plasma into ZIKV-susceptible mice resulted in increased morbidity-including fever, viremia, and viral loads in spinal cord and testes-and increased mortality. Antibody-dependent enhancement may explain the severe disease manifestations associated with recent ZIKV outbreaks and highlights the need to exert great caution when designing flavivirus vaccines.

Recent viral infection in US blood donors and health-related quality of life (HRQOL).

PURPOSE: Blood donors are considered to be one of the healthiest populations, but relatively little is known about their perceived quality of life. The objective was to examine HRQOL in donors infected with HIV, HBV, HCV or HTLV and a comparison group. METHODS: Donors with confirmed viral infection (cases) and donors who tested false-positive (controls) participated in a multicenter study of US blood donors (2010-2013), funded by the National Heart, Lung and Blood Institute (NHLBI). HRQOL was measured by the EuroQol Five Dimension (EQ-5D) instrument and EQ-5D visual analogue scale (VAS). The lower 25th ‰ of EQ-5D index or VAS score of controls was defined as a "lower HRQOL." RESULTS: A total of 1574 controls completed the HRQOL assessment with a mean EQ-5D index of 0.94 (SD = 0.10) and EQ-VAS of 87.6 (SD = 10.6). Mean EQ-5D index for 192 HIV-, 315 HCV- and 195 HTLV-positive donors were significantly lower than the controls (0.86, 0.83 and 0.87; SD = 0.18, 0.20 and 0.16, respectively, p < 0.001). HBV-positive donors (n = 290) had a similar mean EQ-5D index (0.93, SD = 0.14, p = 0.05) to controls. Anxiety/depression was reported by 34 % of cases, compared with 13 % of controls. In multivariable modeling, the odds of lower HRQOL in HIV, HBV, HCV and HTLV cases were 2.1, 1.6, 2.6 and 2.3 times that of controls, respectively (p < 0.05). CONCLUSIONS: HRQOL reported by blood donors with recent viral infections was relatively high but lower than controls. On average, HRQOL among HCV-positive donors was the lowest and HBV-positive donors reported scores similar to donors without infection.

Prevalence, incidence, and risk factors of human immunodeficiency virus infection in blood donors in the Southeastern United States.

BACKGROUND: Human immunodeficiency virus (HIV)-positive blood donors pose a risk to blood safety. The Southeastern United States has the highest reported HIV infection rates. Here we calculate HIV prevalence, incidence, and residual risk in Southeastern US blood donors and report risk factors disclosed by incident donors in counseling sessions. STUDY DESIGN AND METHODS: American Red Cross donation and testing data from 2009 to 2014 for three Southeastern collection regions were used to calculate HIV prevalence, incidence, and residual risk. Incident donors had a previous HIV-negative donation within 730 days of their positive donation. Residual risk was defined as the window period multiplied by incidence. RESULTS: From 2009 to 2014, a total of 236 HIV-positive donors occurred in these regions for an overall prevalence of 8.3 per 100,000 donations. There were 56 incident donors over the 6-year period with incidence decreasing from 7.1 per 100,000 person-years (PYs) in the first two years (2009-2010) to 3.5 in the last two years (2013-2014). Residual risk decreased from 1 in 562,000 to 1 in 1,100,000. The most commonly reported risk factor behavior in male incident donors was men who have sex with men; females expressed no predominant risk factor. CONCLUSION: HIV prevalence and incidence among blood donors in the southeast are higher than other US regions, consistent with general public health surveillance. However, the overall residual risk estimates are low at less than 1 per million. Ongoing monitoring of the blood supply along with educational efforts to provide infected individuals with alternatives to donation remain important initiatives.

Development of a multisystem surveillance database for transfusion-transmitted infections among blood donors in the United States.

BACKGROUND: The frequency of positive test results for transfusion-transmitted infections (TTIs) among blood donors is an important index of safety; thus, appropriate monitoring is critical, particularly when there are changes in policies affecting donor suitability. STUDY DESIGN AND METHODS: Testing algorithms from three large blood systems were reviewed and consensus definitions for a surveillance-positive result for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV) established. In addition, information on each donation, including donor demographics and location, was collected. Combined data were analyzed to characterize the epidemiology of TTIs by person, place, and time. RESULTS: Data from 14.8 million donations were collected for 2011 to 2012, representing more than 50% of the US blood supply. Surveillance-positive rates per 10,000 donations were as follows: HBV, 0.76; HCV, 2.0; HIV, 0.28; and HTLV 0.34. Rates did not vary between the 2 years, although there was variation within a year. With the exception of HTLV, rates were higher among males, and all rates were higher among first-time donations. Window-period donations (those positive only in nucleic acid tests) were infrequent (HBV, 13; HCV, 60; HIV, 14) during the 2-year period. Frequencies of surveillance-positive results varied by donor age and residence location. CONCLUSIONS: We demonstrated that standardized data from multiple major US blood systems can be combined and analyzed for change. However, TTI frequencies are low, impacting their sensitivity to change. Furthermore, observed fluctuations in TTI frequencies may be secondary to changes in blood donor demographics rather than necessarily reflecting the immediate impact of policy modification.

Motivations for donating and attitudes toward screening policies in US blood donors with viral infection.

BACKGROUND: Differences in motivating factors that contribute to the decision to donate blood between infected and uninfected donors may help to identify areas for improving donor education. STUDY DESIGN AND METHODS: As part of a risk factor study, confirmed-positive donors (cases) based on serology-only (human T-lymphotropic virus [HTLV]) or serology and nucleic acid testing (NAT) or NAT-only (human immunodeficiency virus [HIV], hepatitis B virus [HBV], hepatitis C virus [HCV]), and serology-unconfirmed, NAT-negative false-positive donors (controls) were asked about motivations and opinions toward blood donation. "Test seeking" was inferred if a donor answered "yes" to "I wanted to get my test results" and one of the following: "blood center testing is confidential," "free," "more accurate than other test centers," or "tests will identify problems with my blood." Cases were compared to controls using descriptive and multivariable analyses. RESULTS: Whether a case or control, the most common donation reason was "to help someone in need" (>90% in each group). After adjusting for demographic characteristics, test seeking was not significantly associated with infection status. Test seeking was more common in first-time, younger males and nonwhite, non-Hispanic donors. Of donors with HIV, 13% considered selection policies to be unfair, compared with 1, 2, 0.5, and 6% of donors with HBV, HCV, and HTLV and controls, respectively (adjusted odds ratio for HIV cases vs. controls, 3.9; 95% confidence interval, 2.3-6.7). CONCLUSIONS: Most donors give to help those in need, including HIV-positive donors. Our results establish a baseline from which additional studies can be compared focused on alternate ways to reduce noncompliance and improved messaging to ensure that high-risk potential donors understand the reasons for blood donor screening policies.

Differences in Early Cytokine Production Are Associated With Development of a Greater Number of Symptoms Following West Nile Virus Infection.

BACKGROUND: West Nile virus (WNV) is an emerging cause of meningitis and encephalitis in the United States. Although severe neuroinvasive disease and death can occur in rare instances, the majority of infected individuals remain asymptomatic or present with a range of clinical manifestations associated with West Nile fever. METHODS: To better understand the interindividual variability associated with the majority of WNV infections, we evaluated the association of cytokine/chemokine production and outcome of infection among 115 WNV-positive US blood donors identified in 2008-2011. All subjects self-reported symptoms as having occurred during the 2 weeks following blood donation, using a standardized questionnaire. RESULTS: We discovered that, prior to seroconversion, an early potent, largely type I interferon-mediated response correlated with development of a greater number of symptoms in WNV-infected individuals. Interestingly, individuals who developed fewer symptoms had not only a more modest type I interferon response initially, but also a protracted cytokine response after seroconversion, marked by the production of monocyte and T-cell-associated chemokines. CONCLUSIONS: Collectively, our data suggest that, although an early type I interferon response appears to be crucial to control WNV infection, successful immunity may require a modest early response that is maintained during the course of infection.

Distribution of Dengue Virus Types 1 and 4 in Blood Components from Infected Blood Donors from Puerto Rico.

BACKGROUND: Dengue is a mosquito-borne viral disease caused by the four dengue viruses (DENV-1 to 4) that can also be transmitted by blood transfusion and organ transplantation. The distribution of DENV in the components of blood from infected donors is poorly understood. METHODS: We used an in-house TaqMan qRT-PCR assay to test residual samples of plasma, cellular components of whole blood (CCWB), serum and clot specimens from the same collection from blood donors who were DENV-RNA-reactive in a parallel blood safety study. To assess whether DENV RNA detected by TaqMan was associated with infectious virus, DENV infectivity in available samples was determined by culture in mosquito cells. RESULTS: DENV RNA was detected by TaqMan in all tested blood components, albeit more consistently in the cellular components; 78.8% of CCWB, 73.3% of clots, 86.7% of sera and 41.8% of plasma samples. DENV-1 was detected in 48 plasma and 97 CCWB samples while DENV-4 was detected in 21 plasma and 31 CCWB samples. In mosquito cell cultures, 29/111 (26.1%) plasma and 32/97 (32.7%) CCWB samples were infectious. A subset of samples from 29 donors was separately analyzed to compare DENV viral loads in the available blood components. DENV viral loads did not differ significantly between components and ranged from 3-8 log10 PCR-detectable units/ml. CONCLUSIONS: DENV was present in all tested components from most donors, and viral RNA was not preferentially distributed in any of the tested components. Infectious DENV was also present in similar proportions in cultured plasma, clot and CCWB samples, indicating that these components may serve as a resource when sample sizes are limited. However, these results suggest that the sensitivity of the nucleic acid tests (NAT) for these viruses would not be improved by testing whole blood or components other than plasma.

Genomic Assays for Identification of Chikungunya Virus in Blood Donors, Puerto Rico, 2014.

A newly developed transcription-mediated amplification assay was used to detect chikungunya virus infection in 3 of 557 asymptomatic donors (0.54%) from Puerto Rico during the 2014-2015 Caribbean epidemic. Viral detection was confirmed by using PCR, microarray, and next-generation sequencing. Molecular clock analysis dated the emergence of the Puerto Rico strains to early 2013.

Risk factors for retrovirus and hepatitis virus infections in accepted blood donors.

BACKGROUND: Risk factor surveillance among infected blood donors provides information on the effectiveness of eligibility assessment and is critical for reducing risk of transfusion-transmitted infection. STUDY DESIGN AND METHODS: American Red Cross, Blood Systems, Inc., New York Blood Center, and OneBlood participated in a case-control study from 2010 to 2013. Donors with serologic and nucleic acid testing (NAT) or NAT-only confirmed human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), or serology-confirmed human T-lymphotropic virus (HTLV) infections (cases) and donors with false-positive results (controls) were interviewed for putative behavioral and demographic risks. Frequencies and adjusted odds ratios (AORs) from multivariable logistic regression analyses for each exposure in cases compared to controls are reported. RESULTS: In the study, 196 HIV, 292 HBV, 316 HCV, and 198 HTLV cases, and 1587 controls were interviewed. For HIV, sex with an HIV+ person (AOR, 132; 95% confidence interval [CI], 27-650) and male-male sex (AOR, 62; 95% CI, 27-140) were primary risk factors. For HBV, first-time donor status (AOR, 16; 95% CI, 10-27), sex with an injection drug user (IDU; AOR, 11; 95% CI, 5-28), and black race (AOR, 11; 95% CI, 6-19) were primary. For HCV, IDU (AOR, 42; 95% CI, 13-136), first time (AOR, 18; 95% CI, 10-30), and a family member with hepatitis (AOR, 15; 95% CI, 6-40) were primary. For HTLV, sex with an IDU (AOR, 22; 95% CI, 10-48), 55 years old or more (AOR, 21; 95% CI, 8-52], and first time (AOR, 15; 95% CI, 9-24) were primary. CONCLUSIONS: Despite education efforts and risk screening, individuals with deferrable risks still donate; they may fail to understand or ignore or do not believe they have risk. Recipients have potential transfusion-transmitted infection risk because of nondisclosure by donors.