Zika Virus Infection and Solid Organ Transplantation: A New Challenge

Endemic viral infections in immunocompromised hosts: Dengue, Chikungunya, Zika

PURPOSE OF REVIEW

Arbovirus infections are a challenge for immunocompromised hosts who travel to or live in endemic regions or who receive organs or tissues from donors who travel or live in such areas. This review addresses Dengue (DENV), Chikungunya (CHIKV), and Zika (ZIKV) infections in hematological patients, hematopoietic cell or solid organ transplant recipients, and people with HIV (PWH).

RECENT FINDINGS

Transmission is mainly due through Aedes mosquito bite. DENV and ZIKV may also be transmitted through blood, tissues or donor grafts. Clinical manifestations are quite similar and diagnosis requires laboratory confirmation to provide appropriate management. The best diagnostic method is PCR since serology may present false negative results in immunocompromised patients, or cross-reactivity as in the case of DENV and ZIKV. There is no specific treatment for any of these infections.

SUMMARY

Educational and preventive measures are the best strategy: vector control, knowledge of the vector's habits, protection against mosquito bites, avoiding travel to endemic areas or with a current epidemic, and avoiding nonvector transmission according to local recommendations for donor deferral. Vaccination, currently only available for DENV, has not yet been studied in immunocompromised patients and is not currently recommended.

Impact of blood donation biovigilance and transfusion-transmitted infections on organ transplantation

Over 118 million blood donations are collected globally each year. Recipients of blood products include those who experience major trauma or surgery, have acute blood loss and anemia, or impaired bone marrow function. Solid organ transplant recipients often require transfusion of blood products which places them at risk of transfusion-associated adverse events including transfusion-transmitted infection. National hemovigilance networks have documented low rates of transfusion-transmitted infection in the general population. Incidence transfusion-transmitted infection continues to occur in solid organ transplant patients and arises mainly from existing gaps in blood donor biovigilance processes. Emerging infectious diseases have highlighted existing gaps in the donor-recipient pathway to administering safe blood products. This article reviews the current process and regulatory oversight of blood donor biovigilance, including donor screening and microbiological testing, highlights cases of transfusion-transmitted infection documented in the literature, and addresses ways in which biovigilance may be improved, with a focus on the impact of solid organ transplantation.

Susceptibility of solid organ transplant recipients to viral pathogens with zoonotic potential: A mini-review

A substantial number of zoonotic diseases are caused by viral pathogens, representing a significant menace to public health, particularly to susceptible populations, such as pregnant women, the elderly, and immunocompromised individuals. Individuals who have undergone solid organ transplantation frequently experience immunosuppression, to prevent organ rejection, and, thus are more prone to opportunistic infections. Furthermore, the reactivation of dormant viruses can threaten transplant recipients and organ viability. This mini-review examines the up-to-date literature covering potential zoonotic and organ rejection-relevant viruses in solid organ transplant recipients. A comprehensive list of viruses with zoonotic potential is highlighted and the most important clinical outcomes in patients undergoing transplantation are described. Moreover, this mini-review calls attention to complex multifactorial events predisposing viral coinfections and the need for continuous health surveillance and research to understand better viral pathogens' transmission and pathophysiology dynamics in transplanted individuals.

Arboviruses and pregnancy: are the threats visible or hidden?

Mosquito-borne arboviral diseases are a global concern and can have severe consequences on maternal, neonatal, and child health. Their impact on pregnancy tends to be neglected in developing countries. Despite hundreds of millions of infections, 90% pregnancies being exposed, scientific data on pregnant women is poor and sometimes non-existent. Recently and since the 2016 Zika virus outbreak, there has been a newfound interest in these diseases. Through various neuropathogenic, visceral, placental, and teratogenic mechanisms, these arbovirus infections can lead to fetal losses, obstetrical complications, and a wide range of congenital abnormalities, resulting in long-term neurological and sensory impairments. Climate change, growing urbanization, worldwide interconnectivity, and ease of mobility allow arboviruses to spread to other territories and impact populations that had never been in contact with these emerging agents before. Pregnant travelers are also at risk of infection with potential subsequent complications. Beyond that, these pathologies show the inequalities of access to care on a global scale in a context of demographic growth and increasing urbanization. It is essential to promote research, diagnostic tools, treatments, and vaccine development to address this emerging threat.Background The vulnerability of pregnant women and fetuses to emergent and re-emergent pathogens has been notably illustrated by the outbreaks of Zika virus. Our comprehension of the complete scope and consequences of these infections during pregnancy remains limited, particularly among those involved in perinatal healthcare, such as obstetricians and midwives. This review aims to provide the latest information and recommendations regarding the various risks, management, and prevention for pregnant women exposed to arboviral infections.

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

Modeling the spread of the Zika virus by sexual and mosquito transmission

Zika Virus (ZIKV) is a flavivirus that is transmitted predominantly by the Aedes species of mosquito, but also through sexual contact, blood transfusions, and congenitally from mother to child. Although approximately 80% of ZIKV infections are asymptomatic and typical symptoms are mild, multiple studies have demonstrated a causal link between ZIKV and severe diseases such as Microcephaly and Guillain Barré Syndrome. Two goals of this study are to improve ZIKV models by considering the spread dynamics of ZIKV as both a vector-borne and sexually transmitted disease, and also to approximate the degree of under-reporting. In order to accomplish these objectives, we propose a compartmental model that allows for the analysis of spread dynamics as both a vector-borne and sexually transmitted disease, and fit it to the ZIKV incidence reported to the National System of Public Health Surveillance in 27 municipalities of Colombia between January 1 2015 and December 31 2017. We demonstrate that our model can represent the infection patterns over this time period with high confidence. In addition, we argue that the degree of under-reporting is also well estimated. Using the model we assess potential viability of public health scenarios for mitigating disease spread and find that targeting the sexual pathway alone has negligible impact on overall spread, but if the proportion of risky sexual behavior increases then it may become important. Targeting mosquitoes remains the best approach of those considered. These results may be useful for public health organizations and governments to construct and implement suitable health policies and reduce the impact of the Zika outbreaks.

New insights into the recombinant proteins and monoclonal antibodies employed to immunodiagnosis and control of Zika virus infection: A review

An emergent positive-stranded RNA virus, transmitted by mosquitoes with its first case of vertical transmission confirmed in 2015 in Brazil. The Zika virus (ZIKV) fever has received particular attention, mainly related to neurological diseases such as microcephaly in newborns. However, the laboratory diagnosis for ZIKV still faces some challenges due to its cross-reactivity with other flaviviruses, requiring a correct and differential diagnosis, contributing to the good prognosis of patients, especially in pregnant women. Among these, for early diagnosis, the CDC considers the RT-PCR the gold standard, more sensitive and specific, but expensive. Serological tests for the diagnosis of ZIKV can also be found beyond the period when the viral components are detectable in the serum. Inputs to produce more sensitive and specific diagnostic kits and the possibility of viral detection in less invasive samples are among the objectives of recent research on ZIKV. This review outlines recent advances in developing recombinant antigen and antibody-based diagnostic tools for the main flaviviruses in Northeast Brazil, such as ZIKV and Dengue virus (DENV).

Risk constellations, viral infections, and prophylaxis in uterine transplantation

PURPOSE OF REVIEW

Uterine transplantation (UTx) is a burgeoning new category of solid organ transplantation (SOT) that is practiced at several centers worldwide (first transplantation in 2013). Although there are still relatively low numbers of transplants (<75 published in literature), they are increasing in frequency and thus we attempt to discuss the current documented infections in this population as well as theoretical infectious risks and summarize prophylaxis and treatment strategies of centers current performing these procedures.

RECENT FINDINGS

The most reported posttransplantation infection is not surprisingly urinary tract infections, with other documented infections including bacterial infections at site of graft (Enterococcus), herpes simplex virus, cytomegalovirus (CMV), human papillomavirus, Candida, and reportedly posttransplant lymphoproliferative disorder. The net state of immunosuppression and host factors (host colonization and serologic status of viral exposures) plays a significant role in infectious risk and with low numbers of infections documented, much of our guidance surrounding prophylaxis is inferred from SOT literature.

SUMMARY

In this review, we give an overview of described infections in UTx and theoretical infectious risks, detailing how to tailor prophylaxis base on host risk, with specific focus that the goal of transplantation is completion of a successful pregnancy as the desired outcome. Special considerations should be given to pregnant recipients when managing infectious complications and further data collection and reporting regarding infectious complications is crucial to advance this field as numbers of transplantation continue to increase.

Emerging Infection, Vaccination, and Guillain-Barré Syndrome: A Review

Guillain-Barré syndrome (GBS) is an autoimmune disorder of the peripheral nervous system that typically develops within 4 weeks after infection. In addition to conventional infectious diseases with which we are familiar, emerging infectious diseases, such as Zika virus infection and coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have also been suggested to be associated with GBS. GBS is mainly categorized into a demyelinating subtype known as acute inflammatory demyelinating polyneuropathy (AIDP) and an axonal subtype known as acute motor axonal neuropathy (AMAN). Most patients who develop GBS after Zika virus infection or COVID-19 have AIDP. The concept of molecular mimicry between pathogens and human peripheral nerve components was established through studies of AMAN with anti-ganglioside GM1 antibodies occurring after Campylobacter jejuni infection. Although such mimicry between specific pathogens and myelin or Schwann cell components has not been clearly demonstrated in AIDP, a similarity of Zika virus and SARS-CoV-2 proteins to human proteins has been suggested. With the development of global commerce and travel, emerging infectious diseases will continue to threaten public health. From this viewpoint, the development of vaccines and antiviral drugs is important to prepare for and control emerging infectious diseases. Although a decrease in the number of patients after the 2015-2016 Zika epidemic increased the difficulty in conducting phase 3 trials for Zika virus vaccines, the efficacy and safety of new vaccines have recently been demonstrated for COVID-19. In general, vaccines can decrease the risk of infectious disease by stimulating the immune system, and discussions regarding an increased risk of autoimmune disorders, such as GBS, have been ongoing for many years. However, the risk of GBS is not considered a legitimate reason to limit the administration of currently available vaccines, as only a trivial association or no association with GBS has been demonstrated.

Emerging infectious diseases, vaccines and Guillain-Barré syndrome

The recent outbreak of Zika virus infection increased the incidence of Guillain–Barré syndrome (GBS). Following the first reported case of GBS after Zika virus infection in 2013, there has been a considerable increase in the incidence of GBS in endemic countries, such as French Polynesia and Latin American countries. The association between coronavirus disease 2019 (COVID‐19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), and GBS is another emerging research hotspot. Electrophysiological studies have suggested that GBS patients associated with Zika virus infection or COVID‐19 tend to manifest acute inflammatory demyelinating polyneuropathy, rather than acute motor axonal neuropathy (AMAN). Causative autoantibodies, such as anti‐ganglioside antibodies in AMAN associated with Campylobacter jejuni infection, have not been identified in GBS associated with these emerging infectious diseases. Nevertheless, recent studies suggested molecular mimicry between these viruses and human proteins related to GBS. Recent studies have shown the efficacy of new vaccines, containing artificial messenger RNA encoding the spike protein of SARS‐CoV‐2, against COVID‐19. These vaccines are now available in many countries and massive vaccination campaigns are currently ongoing. Although there are long‐standing concerns about the increased risk of GBS after inoculation of conventional vaccines, the risk of GBS is not considered a legitimate reason to limit administration of currently available vaccines, because the benefits outweigh the risks.

HSV-1 and Zika Virus but Not SARS-CoV-2 Replicate in the Human Cornea and Are Restricted by Corneal Type III Interferon

Here, we report our studies of immune-mediated regulation of Zika virus (ZIKV), herpes simplex virus 1 (HSV-1), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the human cornea. We find that ZIKV can be transmitted via corneal transplantation in mice. However, in human corneal explants, we report that ZIKV does not replicate efficiently and that SARS-CoV-2 does not replicate at all. Additionally, we demonstrate that type III interferon (IFN-λ) and its receptor (IFNλR1) are expressed in the corneal epithelium. Treatment of human corneal explants with IFN-λ, and treatment of mice with IFN-λ eye drops, upregulates antiviral interferon-stimulated genes. In human corneal explants, blockade of IFNλR1 enhances replication of ZIKV and HSV-1 but not SARS-CoV-2. In addition to an antiviral role for IFNλR1 in the cornea, our results suggest that the human cornea does not support SARS-CoV-2 infection despite expression of ACE2, a SARS-CoV-2 receptor, in the human corneal epithelium.

Congenital Cytomegalovirus and Zika Infections

Congenital infections affecting newborn infants can have potentially devastating clinical outcomes. They are usually caused by viruses that infect mothers during pregnancy and are transmitted to the fetus or newborn during the prenatal, perinatal or postnatal periods. Congenital cytomegalovirus (cCMV) is the most common congenital infection affecting up to 2.5% of all live births. Even though most infected infants are asymptomatic at birth, cCMV is an important cause of neurodevelopmental impairment and represents the main cause of non-hereditary sensorineural hearing loss. Also, congenital Zika infection has emerged in recent years as a cause of microcephaly and neurodevelopmental delays. Currently, universal screening is not recommended for either infection in pregnant women or newborn infants. Therefore, screening for both conditions is based on multiple factors such as maternal immune status, exposure, and clinical manifestations of the infant. Use of antiviral medications on symptomatic cCMV has shown improvement in outcomes, in contrast with congenital Zika for which there are no therapeutic options available. Even though both viruses can be present in breast milk, there are no recommendations against breastfeeding in full-term infants. Close follow-up for affected infants is necessary to monitor for developmental delays and sensory impairments to implement interventional therapies at the earliest time possible.

Zika; a continuous global threat to public health

Zika virus is transmitted by Aedes mosquitoes, especially, Ae. aegypti and Ae. albopictus. About 80% of the cases do not manifest any symptoms, and it is a self-limiting, mild viral infection. In 20% of the cases and only in fraction of those who do show the symptoms, important complications including Guillaine Barre'syndrome and microcephaly may occur. The emergence of Zika in 2016 in Brazil spreading to about 70 other countries prompted the WHO officials to declare the disease a Public Health Emergency with International Concern (PHEIC). This has led to increased concerns in health authorities of almost all countries making them embark on the strengthened human and vector surveillance, vector control and clinical management of the disease. Although the main vectors of the disease have not yet been able to establish in Iran, because of their occurrence in neighboring countries as well as increased global travel and trade, the country established a national advisory committee for capacity building, vector and human surveillance and case management of Aedes-borne diseases. This study aims at performing a literature review about global situation of Zika and Aedes mosquitoes, their distribution, biology and ecology from the past to present and the threat posed to Iran. Aedes aegypti was historically present in the checklist of Iranian mosquitoes and Ae. albopictus has recently been collected from Southern Iran, however, the species has apparently failed to establish in the country as comprehensive follow up entomological surveillance could not reproduce the findings. Although Zika was not detected in Iran, considering the expansion in tourism, travel and trade to and from Zika infected and Aedes infested countries, suitable climate and favorable prediction for establishment of Aedes vectors, Iran may well be at risk of invasion of Aedes vector species and the diseases they carry. Therefore, this review is of value particularly to health authorities in Iran and other WHO Eastern Mediterranean countries for sustained vigilance and preparedness for early detection and response, including vector control.

Flavivirus Infection Associated with Cerebrovascular Events

Arthropod-borne viruses (arboviruses) of the genus Flavivirus are distributed globally and cause significant human disease and mortality annually. Flavivirus infections present a spectrum of clinical manifestations, ranging from asymptomatic to severe manifestations, including hemorrhage, encephalitis and death. Herein, we describe 3 case reports of cerebrovascular involvement in patients infected by dengue and Zika viruses in Sao Jose do Rio Preto, São Paulo State, Brazil, a hyperendemic area for arbovirus circulation, including dengue, yellow fever, chikungunya and Saint Louis encephalitis viruses. Our findings highlight the potential threat that unusual clinical manifestations may pose to arbovirus disease management and recovery.

Screening of donors and recipients for infections prior to solid organ transplantation

PURPOSE OF REVIEW

This review is a brief overview of current guidelines on screening donors and candidates for bacterial, fungal, parasitic and viral infections prior to solid organ transplantation. The pretransplant period is an important time to evaluate infection exposure risk based on social history as well as to offer vaccinations.

RECENT FINDINGS

One of the major changes in the past few years has been increased utilization of increased Public Health Service risk, HIV positive, and hepatitis C-positive donors. There has also been increased attention to donor and recipient risks for geographically associated infections, such as endemic fungal infections and flaviviruses.

SUMMARY

Screening for donors and candidates prior to organ transplantation can identify and address infection risks. Diagnosing infections in a timely manner can help guide treatment and additional testing. Use of necessary prophylactic treatment in organ recipients can prevent reactivation of latent infections and improve posttransplant outcomes.

Emerging and neglected zoonoses in transplant population

Zoonoses represent a problem of rising importance in the transplant population. A close relationship and changes between human, animal and environmental health (“One Health” concept) significantly influence the transmission and distribution of zoonotic diseases. The aim of this manuscript is to perform a narrative review of the published literature on emerging and neglected zoonoses in the transplant population. Many reports on donor-derived or naturally acquired (re-)emerging arboviral infections such as dengue, chikungunya, West Nile, tick-borne encephalitis and Zika virus infection have demonstrated atypical or more complicated clinical course in immunocompromised hosts. Hepatitis E virus has emerged as a serious problem after solid organ transplantation (SOT), leading to diverse extrahepatic manifestations and chronic hepatitis with unfavorable outcomes. Some neglected pathogens such as lymphocytic choriomeningitis virus can cause severe infection with multi-organ failure and high mortality. In addition, ehrlichiosis may be more severe with higher case-fatality rates in SOT recipients. Some unusual or severe presentations of borreliosis, anaplasmosis and rickettsioses were also reported among transplant patients. Moreover, toxoplasmosis as infectious complication is a well-recognized zoonosis in this population. Although rabies transmission through SOT transplantation has rarely been reported, it has become a notable problem in some countries. Since the spreading trends of zoonoses are likely to continue, the awareness, recognition and treatment of zoonotic infections among transplant professionals should be imperative.

Arboviruses (chikungunya, dengue, and Zika) associated with ophthalmic changes: a focus on aqueous fluid and vitreous humor

The aim of this study was to conduct a bibliographic survey and correlates the presence of arboviroses in the eyeball with the main eye changes presented by the population under study. This study is a systematic review of journals and indexed articles, carried out between January 2019 and June 2019, in which there was a query in the Pubmed/Medline and Scielo databases without temporal restriction. In addition to the aforementioned databases, the Brazilian Association of Organ Transplantation Association database, which provides epidemiological data on organ and tissue transplants in Brazil, was used as a research source. The Midwest region contributed to the increase in the number of organ transplants in Brazil. The number of corneal transplants in Brazil surpassed the number of organ transplants by four times. Several ophthalmic changes associated with Chikungunya, Dengue, and Zika virus infections have been diagnosed; however, few studies have identified the presence of the virus in the eyeball. Arboviruses are of great relevance to public health due to a number of factors, ranging from the diversity of infectious agents involved and the plurality of clinical manifestations because the absence of efficient laboratory support, leading to delayed disease confirmation due to lack of differential diagnostics available. Added to these difficulties is the lack of specific therapy, leaving only the symptomatic control of clinical manifestations as the only treatment option. However, the manifestations are directly associated with the decreased quality of vision and consequently the quality of life of patients.

Detection of Zika virus in paired urine and amniotic fluid samples from symptomatic and asymptomatic women and their babies during a disease outbreak: association with neurological symptoms in newborns

Paired maternal and newborn urine and amniotic fluid from 138 subjects collected during a Zika virus (ZIKV) outbreak was analyzed for ZIKV by gene amplification (RT-qPCR), and the findings were correlated with clinical symptoms and neurological anomalies in the babies. ZIKV was detected in 1 of 9 symptomatic women (11.1%) and in 19 of 129 asymptomatic women (14.7%). Neurological manifestations were present in 19 babies (13.7%), 10 of 20 (50%) positive and 9 of 119 (7.6%) negative (p < 0.001) for ZIKV. Twelve (8.6%) urines collected during gestation were ZIKV-positive; only 2 remained positive for ZIKV postpartum. Six (4.1%) newborn urines collected within 1 day of delivery were ZIKV-positive cases. In 3 of these cases, ZIKV was detected in mother’s urine pre- and postpartum and in both mother’s urine and babies’ urine. Four of the amniotic fluid samples (2.9%) were ZIKV-positive. Among ZIKV-negative babies with neurological sequel, 87.5% were female; in contrast, 72.7% ZIKV-positive babies with neurological abnormalities were male (p = 0.019). We conclude that during a ZIKV outbreak, clinical symptoms and ZIKV detection in biological fluids are poor predictors of infection and adverse neurologic sequel in newborns.

Yellow fever disease in a renal transplant recipient: Case report and literature review

Yellow fever (YF) is a viral disease, with clinical presentation among immunosuppressed patients not fully understood. YF vaccination (YFV), a live vaccine, is contraindicated in patients receiving immunosuppressive treatment due to the risk of developing the disease after vaccination. We report a case of a 50-year-old male recipient who presented wild-type YF five years after a deceased donor kidney transplant. He lived in a YF endemic area and inadvertently received YFV. One day after YFV, the patient presented nausea, vomiting, fever, diarrhea, polyarthralgia, thrombocytopenia, and increased levels of liver function enzymes. The serological test was compatible with YF disease, and quantitative viral load confirmed the diagnosis of wild-type YF. The patient received supportive care for twelve days, with hospital discharge in good clinical condition and stable renal function. One month after discharge, the patient developed de novo donor-specific anti-HLA antibodies (DSA) and histological evidence of endothelial lesion, with a diagnosis of acute antibody-mediated rejection (AMR), treated with plasmapheresis and human IVIg therapy. Six months after therapy, he presented normal renal function with a reduction of DSA MFI. In the reported case, we observed a clinical wild-type YF diagnosed even after YF vaccine administration, with good clinical outcome. De novo DSA and AMR occurred after the recovering of disease, with an adequate response to therapy and preserved allograft function. We reviewed the published literature on YF and YFV in solid organ transplantation.

Neurological Complications After Renal Transplantation: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the prevalence of neurological complication after renal transplantation. The searches were conducted by two independent researchers in the international (PubMed, Web of Science, Scopus, and Google Scholar) and national databases (Magiran and SID) to find the relevant studies published in English and Persian languages since the creation of the databases until January 2019 (without time limitations). The keywords used in the search strategy were: neurologic complication, central nervous system, peripheral nervous system, tremor, CVA, encephalopathy, neurological complications, renal transplantation, renal failure, kidney transplantation, immunosuppression, neurotoxicity, opportunistic infections, CNS, cerebrovascular disease, chronic kidney disease, cognitive impairment, and end-stage renal disease, which were combined using the AND, OR, and NOT operators. Finally, a meta-analysis was conducted in STATA14 statistical software. Based on the random effect model, the total prevalence of neurologic complications in 4674 patients who had undergone the renal transplantation surgery was 7.9% (95% confidence interval [CI]:7.2%,8.7%, I² = 90.1%). The prevalence of infectious, non-infectious and treatment associated neurologic complications was 9.5% (95% CI -8.9, 10.2), 91.8% (95% CI -91.3, 92.4) and 97% (95% CI-95.7%,98.4%) of all neurologic complications in renal transplant patients, respectively. And according to the present subgroup analysis, peripheral neuropathy with a prevalence about 30% (29%) (95% CI -27.6%, 30.4%, I² = 99.4%) was the most common neurological disorder in renal transplant patients followed by tremor with a prevalence of 19.5% (CI -17.6%, 21.3%, I² = 97.1%), cerebrovascular events with a prevalence of 15.1% (95% CI -13.9%, 16.4%, I² = 96.5%), encephalopathy with the prevalence of 13% (95% CI -12%, 14%, I² = 99.3%), headache with a prevalence of 8.3% (95% CI -6.8%, 9.8%, I² = 97.3%) and seizure with a prevalence of 7.4% (CI - 6.5%, 8.3%, I² = 94.6%). The results of the present systematic review and meta-analysis, suggests that post-kidney transplantation neurological disorders, with a prevalence rate about 8%, are relatively common; most of them are caused by immunosuppressive drugs and can be treated by decreasing the dose or switching the immunosuppressive drugs. Neurological disorders are associated with increased mortality; thus, differential diagnosis should be conducted for each individual patient with neurological symptoms after transplantation. It is important for all health care providers to become familiar with the symptoms of neurological disorders that may occur after organ transplants. Recognizing and monitoring these symptoms can reduce the risk of death in kidney transplant recipients. Further research is needed to help the transplant community to identify these issues and problems better in order to achieve the ultimate goal of helping renal patients and sending them back into their normal lives.

Infectious disease risks in pediatric renal transplantation

Renal transplantation is a vital treatment option in children with ESRD with more than 10,000 pediatric kidney transplants and survival rates of greater than 80% at 10 years post-transplant in the USA alone. Despite these advances, infection remains a significant cause of morbidity in pediatric recipients. Screening potential organ donors and recipients is imperative to identify and mitigate infectious risks in the transplant patient. Despite the unique risks of each patient, the timing of many infections post-transplant is predictable. In early post-transplant infections (within 30 days), bacterial and fungal pathogens predominate with donor-derived events and nosocomial infections. In the intermediate period (31-180 days after transplant), latent infections from donor organs, such as EBV and CMV, develop. Late infections occurring > 180 days after the transplant can be due to latent pathogens or community-acquired organisms. Approaching an infectious evaluation in a pediatric kidney recipient requires finesse to diagnose and treat this vulnerable population in a timely manner. The following article highlights the most relevant and common infections including clinical manifestations, risk factors, diagnostic techniques, and treatment options.

Donor-derived infections, lessons learnt from the past, and what is the future going to bring us

PURPOSE OF REVIEW

Donor-derived transmission of infectious diseases is a well-recognized complication of solid organ transplantation (SOT). Most donor-derived disease transmissions are expected. Although uncommon, unexpected donor-derived infections can be associated with significant morbidity and mortality, and as the volume of patients undergoing SOT increases, the number of infections transmitted through organ donation can also be expected to rise. The growing gap between the number of patients waiting for transplantation and available organs continue in fact to be the number one issue facing the transplant community. As a consequence the major focus in organ transplantation has been developing strategies to increase the available organs, including the use of organs from donors with infections or risky behaviors that have disqualified them from the donation in the past.

RECENT FINDINGS

In addition to the commonly reported donor-derived transmissions, an increasing number of studies have reported unusual infections transmitted by SOT.

SUMMARY

Transplant surgeons and physicians should increase their awareness toward uncommon donor-derived infections including them in the differential diagnosis of unusual clinical pictures in their recipients.

Emergent Arboviruses and Renal Transplantation: A Global Challenge

In recent years, Zika, Chikungunya, Dengue, West Nile Fever, and Yellow Fever epidemics have generated some concerns. Besides difficulties related to vector control, there are challenges related to behavior of pathologies not yet fully understood. The transplanted population requires additional care due to immunosuppressive drugs. Furthermore, the potential risk of transmission during donation is another source of uncertainty and generates debate among nephrologists in transplant centers. Do the clinical outcomes and prognoses of these infections tend to be more aggressive in this population? Is there a risk of viral transmission via kidney donation? In this review article, we address these issues and discuss the relationship between arbovirus and renal transplantation.

Travel medicine, transplant tourism, and the solid organ transplant recipient-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review recommendations for prevention and management of travel-related infection in solid organ transplant (SOT) recipients as well as risks associated with transplant tourism. Counseling regarding travel post-transplant should be included during the pre-transplant evaluation, and all SOT recipients should be seen by a travel medicine specialist prior to traveling to destinations with higher rates of infection. Patients should be advised on vaccine-preventable illnesses as well as any need for prophylaxis (ie, malaria) based on their individual travel itineraries. Information with regards to specific recommendations for vaccines and prophylactic medications, along with drug-drug interactions, is summarized. Counseling should be provided for modifiable risks and exposures (ie, food and water safety, and insect bite prevention) as well as non-infectious travel topics. These guidelines also briefly address risks associated with transplant tourism and specific infections to consider if patients seek care for transplants done in foreign countries.

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.

Management of the brain-dead donor in the ICU: general and specific therapy to improve transplantable organ quality

PURPOSE

To provide a practical overview of the management of the potential organ donor in the intensive care unit.

METHODS

Seven areas of donor management were considered for this review: hemodynamic management; fluids and electrolytes; respiratory management; endocrine management; temperature management; anaemia and coagulation; infection management. For each subchapter, a narrative review was conducted.

RESULTS AND CONCLUSIONS

Most elements in the current recommendations and guidelines are based on pathophysiological reasoning, epidemiological observations, or extrapolations from general ICU management strategies, and not on evidence from randomized controlled trials. The cardiorespiratory management of brain-dead donors is very similar to the management of critically ill patients, and the same applies to the management of anaemia and coagulation. Central diabetes insipidus is of particular concern, and should be diagnosed based on clinical criteria. Depending on the degree of vasopressor dependency, it can be treated with intermittent desmopressin or continuous vasopressin, intravenously. Temperature management of the donor is an area of uncertainty, but it appears reasonable to strive for a core temperature of > 35 °C. The indications and controversies regarding endocrine therapies, in particular thyroid hormone replacement therapy, and corticosteroid therapy, are discussed. The potential donor should be assessed clinically for infections, and screening tests for specific infections are an essential part of donor management. Although the rate of infection transmission from donor to receptor is low, certain infections are still a formal contraindication to organ donation. However, new antiviral drugs and strategies now allow organ donation from certain infected donors to be done safely.

Emerging arboviruses and implications for pediatric transplantation: A review

Recent years have brought a rise in newly emergent viral infections, primarily in the form of previously known arthropod-transmitted viruses that have increased significantly in both incidence and geographical range. Of particular note are DENV, CHIKV, and ZIKV, which are transmitted mostly by Aedes species of mosquitoes that exhibit a wide and increasing global distribution. Being important pathogens for the general population, these viruses have the potential to be devastating in the international transplant community, with graft rejection and death as possible outcomes of infection. In this review, we discuss the current state of knowledge for these viruses as well as repercussions of infection in the solid organ and HSCT population, with a focus, when possible, on pediatric patients.

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

Incidence and Outcome of Severe and Nonsevere Thrombocytopenia Associated With Zika Virus Infection-Puerto Rico, 2016

Background

Zika virus (ZIKV) infection has been associated with severe thrombocytopenia. We describe the incidence, clinical manifestations, and outcomes of patients with ZIKV infection and thrombocytopenia.

Methods

We reviewed medical records of patients with ZIKV infection and thrombocytopenia (platelet count <100 ×10⁹ cells/L) in Puerto Rico during 2016. Severe thrombocytopenia was defined by platelet count <20 ×10⁹/L or a platelet count <50 ×10⁹/L and treatment for immune thrombocytopenia (ITP).

Results

Of 37 878 patients with ZIKV infection, 47 (0.1%) had thrombocytopenia in the absence of an alternative etiology (1.4 cases/100 000 population), including 12 with severe thrombocytopenia. Most patients with thrombocytopenia were adult (77%) and male (53%). Platelet nadir occurred a median (range) of 6 (1-16) and 5 (0-34) days after symptom onset for patients with severe and nonsevere thrombocytopenia, respectively. Among patients with severe thrombocytopenia, all had bleeding, 33% were admitted to the intensive care unit, and 8% died; 50% were treated for ITP. Among 5 patients with severe thrombocytopenia who received intravenous immunoglobulin, the median platelet count increase (range) was 112 (65-202) ×10⁹/L. In contrast, among 4 patients who received platelet transfusion, the median increase in platelet count (range) was 8.5 (-6 to 52) ×10⁹/L.

Conclusions

Patients with severe thrombocytopenia and ZIKV infection experienced prominent acute morbidity. Consistent with recommended management, administration of ITP treatments to such patients may be more efficacious than platelet transfusion in resolving thrombocytopenia. Severe thrombocytopenia should be considered a rare outcome of ZIKV infection.

Viral Encephalitis

Viruses are a frequent cause of encephalitis. Common or important viruses causing encephalitis include herpesviruses, arboviruses, enteroviruses, parechoviruses, mumps, measles, rabies, Ebola, lymphocytic choriomeningitis virus, and henipaviruses. Other viruses may cause an encephalopathy. Host factors and clinical features of infection are important to consider in identifying the cause for encephalitis. Cerebrospinal fluid evaluation, serologic/polymerase chain reaction studies, and neuroimaging are cornerstones of diagnostic evaluation in encephalitis. Treatable forms of encephalitis are important to consider in all cases. Central nervous system inflammation may also occur because of postinfectious autoimmunity, such as acute disseminated encephalomyelitis or antibody-mediated encephalitis after herpes simplex virus encephalitis.

Zika and the Eye: Pieces of a Puzzle

Zika virus (ZIKV) is an arbovirus mainly transmitted to humans by mosquitoes from Aedes genus. Other ways of transmission include the perinatal and sexual routes, blood transfusion, and laboratory exposure. Although the first human cases were registered in 1952 in African countries, outbreaks were only reported since 2007, when entire Pacific islands were affected. In March 2015, the first cases of ZIKV acute infection were notified in Brazil and, to date, 48 countries and territories in the Americas have confirmed local mosquito-borne transmission of ZIKV. Until 2015, ZIKV infection was thought to only cause asymptomatic or mild exanthematous febrile infections. However, after explosive ZIKV outbreaks in Polynesia and Latin American countries, it was confirmed that ZIKV could also lead to Guillain-Barré syndrome and congenital birth abnormalities. These abnormalities, which can include neurologic, ophthalmologic, audiologic, and skeletal findings, are now considered congenital Zika syndrome (CZS). Brain abnormalities in CZS include cerebral calcifications, malformations of cortical development, ventriculomegaly, lissencephaly, hypoplasia of the cerebellum and brainstem. The ocular findings, which are present in up to 70% of infants with CZS, include iris coloboma, lens subluxation, cataract, congenital glaucoma, and especially posterior segment findings. Loss of retinal pigment epithelium, the presence of a thin choroid, a perivascular choroidal inflammatory infiltrate, and atrophic changes within the optic nerve were seen in histologic analyses of eyes from deceased fetuses. To date, there is no ZIKV licensed vaccines or antiviral therapies are available for treatment. Preventive measures include individual protection from mosquito bites, control of mosquito populations and the use of barriers measures such as condoms during sexual intercourse or sexual abstinence for couples either at risk or after confirmed infection. A literature review based on studies that analyzed ocular findings in mothers and infants with CZS, with or without microcephaly, was conducted and a theoretical pathophysiologic explanation for ZIKV-ocular abnormalities was formulated.

Zika virus infection and implications for kidney disease

High-level and persistent viruria observed in patients infected by Zika virus (ZIKV) has been well documented. However, renal pathology in acutely infected, immunocompetent patients remains subclinical. Moreover, the long-term impact of ZIKV infection, replication, and persistence in the renal compartment of adults and infants as well as immunosuppressed patients and solid organ transplant (SOT) recipients is unknown. Mechanisms involving host and viral factors that limit or control ZIKV pathogenesis in the renal compartment are important yet unexplored. The observation that long-term viral shedding occurs in the renal compartment in the absence of clinical disease requires further investigation. In this review, I explore Zika virus-induced renal pathology in animal models, the dynamics of virus shedding in urine, virus replication in glomerular cells, ZIKV infection in human renal transplantation, and the potential impact of long-term persistent ZIKV infection in the renal compartment.

Novel genetically stable infectious clone for a Zika virus clinical isolate and identification of RNA elements essential for virus production

Zika virus (ZIKV) is an Aedes mosquitoes-transmitted flavivirus, and its infection may cause severe neurological diseases. A genetically stable infectious clone is essential for ZIKV research, however the toxicity and instability of the viral cDNA in bacteria potentially due to its bacterial promoter activity are major challenges. Here, we constructed a full-length cDNA clone for isolate ZG01 by introducing non-coding changes T1865C/A1868G to reduce the bacterial promoter activity. Wild-type and recombinant ZG01 were highly attenuated in Vero cells, thus we serially passaged wild-type ZG01 through neonatal mice and Vero cells to generate high-titer virus, from which four mutations (4m, C2178T/G2913A/T4991C/T10561C) were identified. Addition of 4m greatly enhanced the infectivity, as ZG01_4m released ZIKV of 10^7.0-10^7.5 plaque-forming unit (PFU)/ml in infected Vero and A549 cells. ZG01_4m resembled the infectivity of high-titer ZG01 in vitro and in vivo. Notably, ZG01_4m plasmid was genetically stable after multiple rounds of transformation-purification in bacteria. Using ZG01_4m, we identified a potential RNA-RNA interaction between 5'UTR and 3'UTR and demonstrated that the nucleotides involved were essential for ZIKV production. The genetically stable ZG01 cDNA clone provides a reliable tool for the study of this important virus, and the strategy used here is feasible for the development of reverse genetics systems for other ZIKV isolates and related flaviviruses.

Emerging sexually transmitted viral infections: 2. Review of Zika virus disease

A sudden increase in the number of newborn infants with microcephaly in Brazil in 2015 brought Zika virus (ZIKV), a less-known infection, to public attention. The rapid increase in the number of cases across the Americas and the devastating complications of infection with ZIKV highlighted the gravity of the situation. Within a relatively short period of time, our knowledge of this infection has significantly increased. This includes the realisation that ZIKV can be sexually transmitted. The aim of the present article is to provide a concise summary on this novel sexually transmitted infection linked to human birth defects and Guillain-Barre Syndrome. According to World Health Organization, individuals living outside areas of ZIKV mosquito transmission where one or both partners have been exposed to ZIKV should abstain from sex or have sex with condoms for at least six months after the last day of possible exposure.

Recent advances in understanding and managing infectious diseases in solid organ transplant recipients

Background: Undergoing solid organ transplantation (SOT) exposes the recipient to various infectious risks, including possible transmission of pathogen by the transplanted organ, post-surgical infections, reactivation of latent pathogens, or novel infections. Recent advances: In the last few years, the emergence of Zika virus has raised concerns in the transplant community. Few cases have been described in SOT patients, and these were associated mainly with moderate disease and favorable outcome; the notable exception is a recent case of fatal meningo-encephalopathy in a heart transplant recipient. Because of the advances in treating hepatitis C, several teams recently started to use organs from hepatitis C-positive donors. The worldwide increasing incidence of multidrug-resistant pathogens, as well as the increasing incidence of Clostridioidesdifficile infection, is of particular concern in SOT patients. In the field of mycology, the main recent therapeutic advance is the availability of isavuconazole for the treatment of invasive aspergillosis and mucormycosis. This drug has the advantage of minimal interaction with calcineurin inhibitors. Regarding the viral reactivations occurring after transplant, cytomegalovirus (CMV) infection is still a significant issue in SOT patients. The management of resistant CMV remains particularly difficult. The approval of letermovir, albeit in bone marrow transplantation, and the therapeutic trial of maribavir bring a ray of hope. Another advancement in management of post-transplant infections is the development of in vitro tests evaluating pathogen-specific immune response, such as immunodiagnostics for CMV and, more recently, tests for monitoring immunity against BK virus. Conclusion: The increasing number of organ transplantations, the use of newer immunosuppressive drugs, and high-risk donors continue to define the landscape of transplant infectious diseases in the current era.

Chikungunya, Dengue, and Zika in Immunocompromised Hosts

PURPOSE OF REVIEW

Describe the characteristics of chikungunya, dengue, and Zika in transplant recipients and immunocompromised hosts.

RECENT FINDINGS

Stem cell/bone marrow grafts, organs, and blood transfusions can transmit CHIKV/DENV/ZIKV infections, which are clinically similar, resembling influenza-like illness. Laboratory confirmation is necessary. In the acute phase, RT-PCR is preferred. DENV and ZIKV serology may cross-react. Delayed engraftment and extended viruria is observed in ZIKV+/HSCT recipients, while longer viremia is observed in DENV+/HSCT patients. Arbovirus persistence in organ tissues is generally unknown. Vaccine development is in early stages for CHIKV/ZIKV. No data is available to recommend the licensed DENV vaccine in transplant recipients. In endemic areas, the assessment of epidemiological risk is mandatory. Donor deferral for 120 days in suspected or confirmed ZIKV+ has been recommended, while CHIKV+ donors should wait 30 days. No deferral is recommended for DENV+ donors. CHIKV/DENV/ZIKV tests should be included in the differential of febrile neutropenia and other transplant syndromes. Reassessment of DENV serology is urgently needed. Prospective studies are necessary to determine the impact of CHIKV/DENV/ZIKV in this special population.

Screening for Zika virus in deceased organ donors in Florida

Zika virus (ZIKV) cases have been detected across the United States (US) and locally acquired cases have been reported in Florida. Currently, there are no ZIKV screening guidelines and no data on the incidence among organ donors in the US. This retrospective study was conducted at Jackson Memorial-Miami Transplant Institute. Positive ZIKV tests in local deceased organ donors were investigated from 6/2016 to 1/2017. We evaluated demographics and risk factors for ZIKV infection among organ donors and transplant outcomes among recipients of donors with positive ZIKV testing. One hundred forty-two donors were analyzed. Ten percent had traveled to ZIKV-endemic countries and 19% had outdoor occupations. Only 3% had positive ZIKV IGG. None had a positive ZIKV IGM or PCR. ZIKV-positive donors were more likely to have traveled to ZIKV-endemic countries (50% vs. 9%, P = .05). The kidneys from a ZIKV-positive donor were transplanted in our hospital with no 6-month rejection, graft failure, or death in the recipients. Our study demonstrated a low prevalence of ZIKV among deceased donors in our community. Despite local ZIKV transmission, ZIKV was more common in donors who traveled to ZIKV-endemic countries. This cohort demonstrated excellent outcomes in recipients of ZIKV IGG-positive donors. However, larger studies are needed.

Mitigating the risk of Zika virus contamination of raw materials and cell lines in the manufacture of biologicals

Ensuring the virological safety of biologicals is challenging due to the risk of viral contamination of raw materials and cell banks, and exposure during in-process handling to known and/or emerging viral pathogens. Viruses may contaminate raw materials and biologicals intended for human or veterinary use and remain undetected until appropriate testing measures are employed. The outbreak and expansive spread of the mosquito-borne flavivirus Zika virus (ZIKV) poses challenges to screening human- and animal -derived products used in the manufacture of biologicals. Here, we report the results of an in vitro study where detector cell lines were challenged with African and Asian lineages of ZIKV. We demonstrate that this pathogen is robustly detectable by in vitro assay, thereby providing assurance of detection of ZIKV, and in turn underpinning the robustness of in vitro virology assays in safety testing of biologicals.

Zika virus: a cause of concern in transplantation?

PURPOSE OF REVIEW

Worldwide, the number of countries reporting Zika virus (ZKV) infection continues to increase. Although 80% of cases are asymptomatic, ZKV has been identified as a neurotropic virus associated with congenital microcephaly, Guillain-Barre' syndrome, and meningoencephalitis. Until recently, infection in transplant recipients has not been identified. This study will review the existing literature on ZKV infection, laboratory testing, and management in transplant recipients.

RECENT FINDINGS

Donor-derived transfusion of contaminated blood products and naturally occurring ZKV infections have been recently reported in solid organ and stem cell transplant recipients, ranging from asymptomatic infections to meningoencephalitis. Interpretation of diagnostic testing of ZKV is evolving, with prolonged viral shedding identified in blood, semen, and urine of unclear significance. Serologic testing may be associated with cross-reactivity with other flaviviridae, requiring plaque reduction neutralization testing for confirmation. Thus far, donor screening guidelines for transplantation have not been established.

SUMMARY

The study reviews the limited existing literature in transplant recipients infected with ZKV, available laboratory testing and management. Ultimately, guidelines are needed for donor screening from high-risk areas, interpretation of studies and management of infected patients to ensure safe transplantation.

Essentials of the Production of Safe and Efficacious State-of-the-Art Polyclonal IgG Concentrates

Severe noninfectious adverse events (AEs) and transmission of pathogens by plasma-derived protein concentrates from the very beginning of their clinical use were threats for recipients (see Chap. 10.1007/978-3-319-68038-5_11 for additional information). “Standard IgG” preparations were the first available for clinical use. They were produced by the cold-ethanol fractionation methods and did not make an exception. Noninfectious severe AEs occurred while infectious AEs were rarely reported. Indeed, prior to the introduction of mass screening for infection markers of plasma donations, inadvertent transmission of HIV to recipients of factor VIII and factor IX concentrates did occur, while IgG concentrates obtained from the same plasma pool did rarely transmit HIV (Morgenthaler 2001). Rare transmissions were restricted to products not exposed to low pH. The very few incidences of HIV and some incidences of HCV transmission by IgG concentrates in the early 1990s together with many cases of coagulation factor concentrates transmitted viral disease clearly demonstrated the need to establish standardized measures to render plasma products pathogen safe. In the second half of the 1990s, authorities shifted regulatory emphasis from a scientific review of the processes to a focus on compliance to current good manufacturing practice (cGMP). The focus on cGMP compliance was applied to all aspects of plasma fractionation and the clinical use of plasma products. Court injunctions and warning letters were the consequences of this paradigm shift by authorities. This in turn resulted in a paradigm shift how the modern plasma industry operates (Steinhardt 1998).

Zika virus reservoirs: Implications for transmission, future outbreaks, drug and vaccine development

Zika virus (ZIKV) was recently declared as a 'Global Health Emergency' by the World Health Organization. Various tissue reservoirs of ZIKV in infected humans and animals models have been observed, the implications of which are not known. Compared to other Flaviviruses, sexual transmission and persistence in the genitourinary tract seem to be unique to ZIKV. ZIKV persistence and shedding in bodily secretions (e.g. saliva, semen) is a concern for potential disease spread and could pose challenges in diagnosis, regulatory guidelines and drug/vaccine development. Murine and non-human primate models could be useful to study the role of tissue reservoirs in the development of prophylactic or therapeutic strategies. There is a need for meta-analysis of the ZIKV infection and virus shedding data from infected patients and ZIKV animal models, and additional research is needed to fully comprehend the long term implications of tissue reservoirs on ZIKV disease pathogenesis and biology.

Synergistic antiviral activity of Sofosbuvir and type-I interferons (α and β) against Zika virus

Zika virus (ZIKV) is transmitted by mosquitoes and causes Dengue-like illness, neurological symptoms such as Guillain-Barré Syndrome and microcephaly in children born to infected pregnant mothers. Recently, the World Health Organization (WHO) declared ZIKV infection as a Global Health Emergency. However, there are no known prophylactic or therapeutic measures against this virus. As a proof of concept toward combination therapeutic strategy against ZIKV, combinations of host-targeted (Interferon-α and Interferon-β) and direct acting (Sofosbuvir) antivirals were evaluated in a hepatic cell line (Huh7) using a Cytoprotection (CP) assay. The combination of these antivirals resulted in synergistic inhibition of ZIKV infection in the in vitro CP assay. Additional testing in a ZIKV yield assay demonstrated that combination treatment of these antivirals conferred >2-log reduction in the release of viral RNA. Measurement of ZIKV proteins in the cells infected with multiple ZIKV strains isolated from different geographical regions (Americas, Asia, and Africa) using an immunofluorescence assay confirmed the effective antiviral activity of this combination against ZIKV. These results demonstrate the in vitro proof of concept (POC) for using a combination approach utilizing the strengths of both virus and host-targeted antivirals. These results suggest the effectiveness of the combination strategy in combating ZIKV, in the in vitro systems. Further evaluation of such combination therapies in vivo might provide an impetus for the development of effective ZIKV therapeutic strategies.

Clinical, laboratory and virological data from suspected ZIKV patients in an endemic arbovirus area

BACKGROUND

The emergence of Zika virus (ZIKV) presents new challenges to both clinicians and public health authorities. Overlapping clinical features between the diseases caused by ZIKV, dengue (DENV) and chikungunya (CHIKV) and the lack of validated serological assays for ZIKV make accurate diagnosis difficult. Brazilian authorities largely rely on clinical and epidemiological data for the epidemiological and clinical classifications of most ZIKV cases.

OBJECTIVE

To report the laboratory and clinical profiles of patients diagnosed with Zika fever based only on clinical and epidemiological data.

STUDY DESIGN

We analyzed 433 suspected cases of ZIKV identified by the attending physician based on proposed clinical criteria. The samples were also screened for ZIKV, DENV and CHIKV using PCR.

RESULTS

Of the 433 patients analyzed, 168 (38.8%) were laboratory-confirmed for arboviruses: 96 were positive for ZIKV, 67 were positive for DENV (56 for DENV-2, 9 for DENV-1, and 2 for DENV-4), four were positive for co-infection with ZIKV/DENV-2, and one was positive for CHIKV. The most common signs or symptoms in the patients with laboratory-confirmed ZIKV were rash (100%), arthralgia (77.1%), fever (74.0%), myalgia (74.0%) and non-purulent conjunctivitis (69.8%). In patients with laboratory-confirmed DENV infections, the most frequently observed symptoms were rash (100%), fever (79.1%), myalgia (74.6%), headache (73.1%) and arthralgia (70.1%). The measure of association between clinical manifestations and laboratory manifestations among patients with ZIKV and DENV detected a statistically significant difference only in abdominal pain (p=0.04), leukopenia (p=0.003), and thrombocytopenia (p=0.01).

CONCLUSION

Our data suggests that clinical and epidemiological criteria alone are not a good tool for ZIKV and DENV differentiation, and that laboratory diagnosis should be mandatory.

Zika Virus Infection

In less than 2 years since entry into the Americas, we have witnessed the emergent spread of Zika virus into large subsets of immunologically naïve human populations and then encountered the devastating effects of microcephaly and brain anomalies that can arise from in utero infection with the virus. Diagnostic evaluation and management of affected infants continues to evolve as our understanding of Zika virus rapidly advances. The development of a safe and effective vaccine holds the potential to attenuate the spread of infection and limit the impact of congenital infection.

Zika Virus Infection of the Human Glomerular Cells: Implications for Viral Reservoirs and Renal Pathogenesis

Background

Zika virus (ZIKV) infection in the human renal compartment has not been reported. Several clinical reports have describe high-level persistent viral shedding in the urine of infected patients, but the associated mechanisms have not been explored until now. The current study examined cellular components of the glomerulus of the human kidney for ZIKV infectivity.

Methods

I infected primary human podocytes, renal glomerular endothelial cells (GECs), and mesangial cells with ZIKV. Viral infectivity was analyzed by means of microscopy, immunofluorescence, real-time reverse-transcription polymerase chain reaction (RT-PCR), and quantitative RT-PCR (qRT-PCR), and the proinflammatory cytokines interleukin 1β, interferon β, and RANTES (regulated on activation of normal T cells expressed and secreted) were assessed using qRT-PCR.

Results

I show that glomerular podocytes, renal GECs, and mesangial cells are permissive for ZIKV infection. ZIKV infectivity was confirmed in all 3 cell types by means of immunofluorescence staining, RT-PCR, and qRT-PCR, and qRT-PCR analysis revealed increased transcriptional induction of interleukin 1β, interferon β, and RANTES in ZIKV-infected podocytes at 72 hours, compared with renal GECs and mesangial cells.

Conclusions

The findings of this study support the notion that the glomerulus may serve as an amplification reservoir for ZIKV in the renal compartment. The impact of ZIKV infection in the human renal compartment is unknown and will require further study.

Ocular effects of Zika virus-a review

Zika virus was considered an innocent pathogen while restricted to the African and Asian population; however, after reaching the Americas in March 2015, it became a global threat. Despite usually causing mild or no symptoms in infected adults, Zika virus displays a different behavior toward fetuses. When infected during gestation, fetuses have their immature neural cells killed by the virus and consequently have devastating findings at birth. In the past year the drastic effects of Zika virus infection in newborns include neurological, ophthalmological, audiological, and skeletal abnormalities. These findings represent a new entity called congenital Zika syndrome. We summarize the ocular findings of congenital Zika Syndrome, as well as the current understanding of the illness, systemic manifestations, laboratory investigation, differential diagnosis, prophylaxis, and treatment for this disorder.

Development of standard methods for Zika virus propagation, titration, and purification

The emergence of Zika virus (ZIKV) infection has stimulated several research groups to study and collaborate to understand virus biology and pathogenesis. These efforts may assist with the development of antiviral drugs, vaccines and diagnostic tests, as well as to promote advancements in public health policies. Here, we aim to develop standard protocols for propagation, titration, and purification of ZIKV strains, by systematically testing different cell types, kinetics, multiplicity of infection and centrifugation protocols. ZIKV produces a productive infection in human, non-human primate, and rodents-derived cell lines, with different efficacies. The highest yield of ZIKV-AFR and ZIKV-BR infectious progeny was obtained at 7days post infection in C6/36 cells (7×10⁷ and 2×10⁸ PFU/ml, respectively). However, high titers of ZIKV-AFR could be obtained at earlier time points in Vero cells (2.5×10⁷PFU/ml at 72hpi), whereas ZIKV-BR titers reached 10⁸ PFU/ml at 4dpi in C6/36 cells. High yield of purified virus was obtained by purification through a discontinuous sucrose gradient. This optimized procedure will certainly contribute to future studies of virus structure and vaccine development. Beyond the achievement of efficient virus propagation, the normalization of these protocols will also allow different laboratories around the world to better compare and discuss data regarding different features of ZIKV biology and disease, contributing to more efficient collaborations and progression in ZIKV research.