Estimating incidence of infection from diverse data sources: Zika virus in Puerto Rico, 2016.

Emerging epidemics are challenging to track. Only a subset of cases is recognized and reported, as seen with the Zika virus (ZIKV) epidemic where large proportions of infection were asymptomatic. However, multiple imperfect indicators of infection provide an opportunity to estimate the underlying incidence of infection. We developed a modeling approach that integrates a generic Time-series Susceptible-Infected-Recovered epidemic model with assumptions about reporting biases in a Bayesian framework and applied it to the 2016 Zika epidemic in Puerto Rico using three indicators: suspected arboviral cases, suspected Zika-associated Guillain-Barré Syndrome cases, and blood bank data. Using this combination of surveillance data, we estimated the peak of the epidemic occurred during the week of August 15, 2016 (the 33rd week of year), and 120 to 140 (50% credible interval [CrI], 95% CrI: 97 to 170) weekly infections per 10,000 population occurred at the peak. By the end of 2016, we estimated that approximately 890,000 (95% CrI: 660,000 to 1,100,000) individuals were infected in 2016 (26%, 95% CrI: 19% to 33%, of the population infected). Utilizing multiple indicators offers the opportunity for real-time and retrospective situational awareness to support epidemic preparedness and response.

Modes of Transmission of Zika Virus.

For >60 years, Zika virus (ZIKV) has been recognized as an arthropod-borne virus with Aedes species mosquitoes as the primary vector. However in the past 10 years, multiple alternative routes of ZIKV transmission have been identified. We review the available data on vector and non-vector-borne modes of transmission and interventions undertaken, to date, to reduce the risk of human infection through these routes. Although much has been learned during the outbreak in the Americas on the underlying mechanisms and pathogenesis of non-vector-borne ZIKV infections, significant gaps remain in our understanding of the relative incidence of, and risk from, these modes compared to mosquito transmission. Additional research is urgently needed on the risk, pathogenesis, and effectiveness of measures to mitigate non-vector-borne ZIKV transmission.

Continued decline in blood collection and transfusion in the United States-2015.

BACKGROUND: In 2011 and 2013, the National Blood Collection and Utilization Survey (NBCUS) revealed declines in blood collection and transfusion in the United States. The objective of this study was to describe blood services in 2015. STUDY DESIGN AND METHODS: The 2015 NBCUS was distributed to all US blood collection centers, all hospitals performing at least 1000 surgeries annually, and a 40% random sample of hospitals performing 100 to 999 surgeries annually. Weighting and imputation were used to generate national estimates for units of blood and components collected, deferred, distributed, transfused, and outdated. RESULTS: Response rates for the 2015 NBCUS were 78.4% for blood collection centers and 73.9% for transfusing hospitals. In 2015, 12,591,000 units of red blood cells (RBCs) (95% confidence interval [CI], 11,985,000-13,197,000 units of RBCs) were collected, and 11,349,000 (95% CI, 10,592,000-11,747,000) were transfused, representing declines since 2013 of 11.6% and 13.9%, respectively. Total platelet units distributed (2,436,000; 95% CI, 2,230,000-2,642,000) and transfused (1,983,000; 95% CI, 1,816,000 = 2,151,000) declined by 0.5% and 13.1%, respectively, since 2013. Plasma distributions (3,714,000; 95% CI, 3,306,000-4,121,000) and transfusions (2,727,000; 95% CI, 2,594,000-2,859,000) in 2015 declined since 2013. The median price paid per unit in 2015-$211 for leukocyte-reduced RBCs, $524 for apheresis platelets, and $54 for fresh frozen plasma-was less for all components than in 2013. CONCLUSIONS: The 2015 NBCUS findings suggest that continued declines in demand for blood products resulted in fewer units collected and distributed Maintaining a blood inventory sufficient to meet routine and emergent demands will require further monitoring and understanding of these trends.

Use of Blood Donor Screening Data to Estimate Zika Virus Incidence, Puerto Rico, April-August 2016.

Puerto Rico has been heavily impacted by Zika virus, a mosquitoborne flavivirus that emerged in the Americas during 2015. Although most persons with Zika virus show no symptoms, the virus can cause neurologic and other complications, including fetal microcephaly. Local Zika virus transmission in Puerto Rico has been reported since December 2015. To prevent transfusion-associated transmission, local blood collection ceased in March 2016 but resumed in April 2016 after Zika virus screening of blood donations became available. Using data from screening of blood donations collected by the 2 largest blood centers in Puerto Rico during April 3-August 12, 2016, and assuming a 9.9-day duration of viremia, we estimated that 469,321 persons in Puerto Rico were infected during this period, for an estimated cumulative incidence of 12.9%. Results from blood donation screening during arboviral outbreaks can supplement routine clinical and surveillance data for improved targeting of prevention efforts.

Update: Ongoing Zika Virus Transmission - Puerto Rico, November 1, 2015-July 7, 2016.

Zika virus is a flavivirus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, and infection can be asymptomatic or result in an acute febrile illness with rash (1). Zika virus infection during pregnancy is a cause of microcephaly and other severe birth defects (2). Infection has also been associated with Guillain-Barré syndrome (GBS) (3) and severe thrombocytopenia (4,5). In December 2015, the Puerto Rico Department of Health (PRDH) reported the first locally acquired case of Zika virus infection. This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico (6,7). A confirmed case of Zika virus infection is defined as a positive result for Zika virus testing by reverse transcription-polymerase chain reaction (RT-PCR) for Zika virus in a blood or urine specimen. A presumptive case is defined as a positive result by Zika virus immunoglobulin M (IgM) enzyme-linked immunosorbent assay (MAC-ELISA)* and a negative result by dengue virus IgM ELISA, or a positive test result by Zika IgM MAC-ELISA in a pregnant woman. An unspecified flavivirus case is defined as positive or equivocal results for both Zika and dengue virus by IgM ELISA. During November 1, 2015-July 7, 2016, a total of 23,487 persons were evaluated by PRDH and CDC Dengue Branch for Zika virus infection, including asymptomatic pregnant women and persons with signs or symptoms consistent with Zika virus disease or suspected GBS; 5,582 (24%) confirmed and presumptive Zika virus cases were identified. Persons with Zika virus infection were residents of 77 (99%) of Puerto Rico's 78 municipalities. During 2016, the percentage of positive Zika virus infection cases among symptomatic males and nonpregnant females who were tested increased from 14% in February to 64% in June. Among 9,343 pregnant women tested, 672 had confirmed or presumptive Zika virus infection, including 441 (66%) symptomatic women and 231 (34%) asymptomatic women. One patient died after developing severe thrombocytopenia (4). Evidence of Zika virus infection or recent unspecified flavivirus infection was detected in 21 patients with confirmed GBS. The widespread outbreak and accelerating increase in the number of cases in Puerto Rico warrants intensified vector control and personal protective behaviors to prevent new infections, particularly among pregnant women.

Declining blood collection and utilization in the United States.

BACKGROUND: The Department of Health and Human Services National Blood Collection and Utilization Survey (NBCUS) has been conducted biennially since 1997. Data are used to estimate national blood collection and utilization. STUDY DESIGN AND METHODS: The 2013 Department of Health and Human Services NBCUS is a cross-sectional survey of all US blood collection centers and hospitals as listed in the 2012 American Hospital Association Annual Survey database that perform at least 100 inpatient surgical procedures annually. The study objective was to estimate, with 95% confidence intervals (CIs), the number of blood and blood components collected and transfused in the United States. RESULTS: In 2013, a total of 14,237,000 whole blood and apheresis red blood cell (RBC) units (95% CI, 13,639,000-14,835,000) were collected with 13,395,000 available for transfusion. Of these, 13,180,000 (95% CI, 12,389,000-13,972,000) whole blood and RBC units were transfused. This represented a 4.4% decline in the number of transfused units compared to 2011. Outdated (i.e., expired without being transfused) whole blood and RBC units declined by 17.3%. Apheresis (2,318,000; 95% CI, 2,154,000-2,482,000) and whole blood-derived platelet (PLT; 130,000; 95% CI, 23,000-237,000) distribution declined in 2013. Total PLT transfusions increased in 2013 (2,281,000) in comparison to 2011 (2,169,000). Total plasma units distributed (4,338,000) and transfused (3,624,000) declined. CONCLUSION: Both blood collection and utilization have declined, but the gap between collection and utilization is narrowing. As collections decline further and hospitals decrease transfusions and manage products more efficiently, the decline in surplus inventory may be a concern for disaster preparedness or other unexpected utilization needs.

How is national recipient hemovigilance conducted in the United States?

A national recipient hemovigilance system was introduced in the United States in 2010, when voluntary enrollment began as part of the National Healthcare Safety Network (NHSN) Hemovigilance Module. NHSN is a secure, Web-based surveillance system operated by the Centers for Disease Control and Prevention and used by US health care facilities to report a variety of patient safety information. The Hemovigilance Module is used for comprehensive monitoring of transfusion-related adverse events. Participating facilities can utilize analytic tools available within the module to identify opportunities for enhancing transfusion safety, evaluate the effectiveness of interventions, and compare facility specific transfusion-related data to aggregate national estimates. Data may be voluntarily shared by facilities with external partners for patient safety improvement initiatives and to fulfill reporting mandates. We describe the key characteristics of the Hemovigilance Module, highlight the benefits for participating facilities, and discuss the use of reported data for establishing national estimates of transfusion-associated adverse events to identify gaps in transfusion safety and opportunities for interventions. National hemovigilance systems are essential to recognize gaps in transfusion safety and identify opportunities for interventions to improve patient safety and outcomes.

Transfusion-related adverse reactions reported to the National Healthcare Safety Network Hemovigilance Module, United States, 2010 to 2012.

BACKGROUND: In 2010, health care facilities in the United States began voluntary enrollment in the National Healthcare Safety Network (NHSN) Hemovigilance Module. Participants report transfusion practices; red blood cell, platelet (PLT), plasma, and cryoprecipitate units transfused; and transfusion-related adverse reactions and process errors to the Centers for Disease Control and Prevention through a secure, Internet-accessible surveillance application available to transfusing facilities. STUDY DESIGN AND METHODS: Facilities submitting at least 1 month of transfused components data and adverse reactions from January 1, 2010, to December 31, 2012, were included in this analysis. Adverse reaction rates for transfused components, stratified by component type and collection and modification methods, were calculated. RESULTS: In 2010 to 2012, a total of 77 facilities reported 5136 adverse reactions among 2,144,723 components transfused (239.5/100,000). Allergic (46.8%) and febrile nonhemolytic (36.1%) reactions were most frequent; 7.2% of all reactions were severe or life-threatening and 0.1% were fatal. PLT transfusions (421.7/100,000) had the highest adverse reaction rate. CONCLUSION: Adverse transfusion reaction rates from the NHSN Hemovigilance Module in the United States are comparable to early hemovigilance reporting from other countries. Although severe reactions are infrequent, the numbers of transfusion reactions in US hospitals suggest that interventions to prevent these reactions are important for patient safety. Further investigation is needed to understand the apparent increased risk of reactions from apheresis-derived blood components. Comprehensive evaluation, including data validation, is important to continued refinement of the module.

Planning for success predicts virus suppressed: results of a non-controlled, observational study of factors associated with viral suppression among HIV-positive persons following jail release.

In the United States, jail frequently disrupts access to HIV care. EnhanceLink, a 10-site demonstration project promoting linkage to HIV primary care upon jail discharge, offered an opportunity to gauge how many releasees had favorable clinical outcomes. Individual level data were available on 1270 participants. Persons never discharged from the correctional environment were excluded. Multivariate logistic regression identified factors associated with viral suppression 6 months post discharge (6M-VL < 400). Among 1082 individuals eligible for follow-up evaluation, 25.7 % had 6M-VL < 400. 6M-VL < 400 was associated with case managers assessing whether help was needed for linkage to HIV-related medical services and clients keeping an appointment with a case manager. The adjusted odds ratio (aOR) of 6M-VL < 400 associated with attending a meeting with an HIV care provider within 30 days of release was 1.85. The results of this non-controlled, observational study support further development and rigorous evaluation of transitional care programs for HIV-positive jailed persons across the country.

HIV-positive and in jail: race, risk factors, and prior access to care.

UNLABELLED: Black individuals represent 13 % of the US population but 46 % of HIV positive persons and 40 % of incarcerated persons. The national EnhanceLink project evaluated characteristics of HIV-positive jail entrants at ten sites and explored associations between race and HIV disease state. Between 1/2008 and 10/2011, 1,270 study participants provided demographic and clinical data. Adjusted odds ratios (aORs) were calculated for advanced HIV disease (CD4 < 200 cells/mm(3)) and uncontrolled viremia (viral load > 400 copies/ml) for Black (n = 807) versus non-Black (n = 426) participants. Sixty-five percent of HIV-positive jail participants self-identified as Black. Among all participants, fewer than half had a high school diploma or GED, the median number of lifetime arrests was 15, and major mental illness and substance abuse were common. Black participants were more likely to be older than non-Black participants, and less likely to have health insurance (70 vs 83 %) or an HIV provider (73 vs 81 %) in the prior 30 days. Among all male study participants (n = 870), 20 % self-identified as homosexual or bisexual. Black male participants were more likely to be homosexual or bisexual (22 vs 16 %) and less likely to have a history of injection drug use (20 vs 50 %) than non-Black male participants. Advanced HIV disease was associated with self-identification as Black (aOR = 1.84, 95 % CI 1.16-2.93) and time since HIV diagnosis of more than two years (aOR = 3.55, 95 % CI 1.52-8.31); advanced disease was inversely associated with age of less than 38 years (aOR = 0.41, 95 % CI 0.24-0.70). Uncontrolled viremia was inversely associated with use of antiretroviral therapy (ART) in the prior 7 days (aOR = 0.25, 95 % CI 0.15-0.43) and insurance coverage in the prior 30 days (aOR = 0.46, 95 % CI 0.26-0.81). CONCLUSIONS: The racial disparities of HIV and incarceration among Black individuals in the US are underscored by the finding that 65 % of HIV-positive jail participants self-identified as Black in this ten-site study. Our study also found that 22 % of Black male participants self-identified as men who have sex with men (MSM). We believe these findings support jails as strategic venues to reach heterosexual, bisexual, and homosexual HIV-positive Black men who may have been overlooked in the community. Among HIV-positive jail entrants, Black individuals had more advanced HIV disease. Self-identification as Black was associated with a lower likelihood of having health insurance or an HIV provider prior to incarceration. HIV care and linkage interventions are needed within jails to better treat HIV and to address these racial disparities.