Zika Virus Diagnosis Research Articles

Advances in Epidemiology, Biology and Laboratory Diagnosis of Zika Virus

Zika virus (ZIKV) was spread to both eastward and westward from Uganda where the virus was identified approximately in 1947 by a group of arbovirus researchers. In 2015, ZIKV reached Americas with major outbreaks in Brazil. Most countries with mosquito transmitted ZIKV infection are located in tropical and subtropical areas, where ZIKV is endemic with other flaviviruses, including JEV, dengue and yellow fever virus. Approximately 40 countries in Central and South Americas and territories in South Pacific Islands and South East Asia show autochthonous ZIKV endemics. American lineage of ZIKV is known significantly to be mutated in susceptibility to host and in pathogenicity from Asian and Asian lineages approximately since 2014. Early and specific identification of ZIKV infection is very important for the effective management of patients. First of all, optimal collection of specimens for the laboratory diagnosis is required for both nucleic acid testing (NAT) and serological tests. Specimens for NAT tests and serological tests should be determined by the available laboratory resources, work-flow in each laboratory and the geographic areas of specimen collected in addition to days after showing symptoms. Testing strategy for specific differentiation among flaviviruses will vary depending on the prevalence of viruses known to be circulating in the area where the patients were exposed. NAT will be employed for the patients presenting with onset of symptoms less than 7 days. Advanced diagnostic technologies should be continuously developed for the increase of specificity and sensitivity of ZIKV diagnosis.

Serodiagnosis of Zika virus (ZIKV) infections by a novel NS1-based ELISA devoid of cross-reactivity with dengue virus antibodies: a multicohort study of assay performance, 2015 to 2016

Serological diagnosis of Zika virus (ZIKV) infections is challenging due to high cross-reactivity between flaviviruses. We evaluated the diagnostic performance of a novel anti-ZIKV ELISA based on recombinant ZIKV non-structural protein 1 (NS1). Assay sensitivity was examined using sera from 27 patients with reverse transcription (RT)-PCR-confirmed and 85 with suspected ZIKV infection. Specificity was analysed using sera from 1,015 healthy individuals. Samples from 252 patients with dengue virus (n = 93), West Nile virus (n = 34), Japanese encephalitis virus (n = 25), chikungunya virus (n = 19) or Plasmodium spp. (n = 69) infections and from 12 yellow fever-vaccinated individuals were also examined. In confirmed ZIKV specimens collected ≥ 6 days after symptom onset, ELISA sensitivity was 58.8% (95% confidence interval (CI): 36.0–78.4) for IgM, 88.2% (95% CI: 64.4–98.0) for IgG, and 100% (95% CI: 78.4–100) for IgM/IgG, at 99.8% (95% CI: 99.2–100) specificity. Cross-reactivity with high-level dengue virus antibodies was not detected. Among patients with potentially cross-reactive antibodies anti-ZIKV positive rates were 0.8% (95% CI: 0–3.0) and 0.4% (95% CI: 0–2.4) for IgM and IgG, respectively. Providing high specificity and low cross-reactivity, the NS1-based ELISA has the potential to aid in counselling patients, pregnant women and travellers after returning from ZIKV-endemic areas.

Simple and Highly Sensitive Molecular Diagnosis of Zika Virus by Lateral Flow Assays

We have developed a simple, user-friendly, and highly sensitive Zika virus (ZIKV) detection method by incorporating optimized reverse transcription loop-mediated isothermal amplification (RT-LAMP) and a lateral flow assay (LFA). The optimized RT-LAMP reaction was carried out using Bst 3.0 polymerase, which has robust and fast isothermal amplification performance even in the presence of high concentrations of inhibitors; this permitted the amplification of ZIKV RNA in pure water and human whole blood. In addition, the strong reverse transcription activity of Bst 3.0 polymerase enabled specific ZIKV RNA amplification without extra addition of reverse transcriptase. The RT-LAMP condition was optimized by adjusting the Mg2+ and dNTP mix concentration to extirpate nontarget amplification, which is caused by nonspecific primer dimers amplification. After 30 min of RT-LAMP reaction, the resultant amplicons were simply and rapidly analyzed by the LFA test in less than 5 min. The optimized RT-LAMP combined with the LFA allowed specific ZIKV RNA detection down to the single copy level within 35 min.

Zika Virus: Pathology From the Pandemic.

-As the number of Zika virus (ZIKV) infections continues to grow, so, too, does the spectrum of recognized clinical disease, in both adult and congenital infections. Defining the tissue pathology associated with the various disease manifestations provides insight into pathogenesis and diagnosis, and potentially future prevention and treatment, of ZIKV infections. -To summarize the syndromes and pathology associated with ZIKV infection, the implications of pathologic findings in the pathogenesis of ZIKV disease, and the use of pathology specimens for diagnosis of ZIKV infection. -The major sources of information for this review were published articles obtained from PubMed and pathologic findings from cases submitted to the Infectious Diseases Pathology Branch at the Centers for Disease Control and Prevention. -Pathologic findings associated with ZIKV infection are characteristic but not specific. In congenital Zika syndrome, tissue pathology is due to direct viral infection of neural structures, whereas in Guillain-Barré syndrome, pathology is likely due to a postviral, aberrant host-directed immune response. Both fetal and placental pathology specimens are useful for ZIKV diagnosis by molecular and immunohistochemical assays; however, the implications of ZIKV detection in placentas from second- and third-trimester normal live births are unclear, as the potential postnatal effects of late gestational exposure remain to be seen.

Zika virus infection: epidemiology, clinical manifestations and diagnosis.

Zika virus (ZIKV) is an arbovirus previously believed to cause only a mild and self-limiting illness. Recently, it has emerged as a new public health threat that caused a large outbreak in French Polynesia in 2013-2014 and since 2015 an explosive outbreak in Brazil, with an increase in severe congenital malformations (microcephaly) and neurological complications, mainly Guillain-Barré syndrome (GBS). Since then, it has spread through the Americas. On 1 February 2016, the WHO declared the ZIKV epidemic in Brazil a Public Health Emergency of International Concern. We reviewed the epidemiology of ZIKV infection, clinical presentations and diagnosis. We highlighted the clinical features and nonvector borne transmission of the virus. Association between ZIKV infection and severe foetal outcomes, including microcephaly and other birth defects; increased rate of GBS and other neurological complications due to the ongoing ZIKV outbreak; increased evidence to date of ZIKV being the only arbovirus linked to sexual transmission; the challenge of ZIKV diagnosis; and the need for a specific point-of care test in epidemic scenarios. The findings illustrate the emergence of a viral disease with the identification of new associated disorders, new modes of transmission, including maternal-foetal and sexual transmission.

P.1.a.011 - Schizophrenia and contributory genetic combinations in Armenians

The nucleic acid-based polymerase chain reaction (PCR) assay is commonly applied to detect infection with Zika virus (ZIKV). However, the time- and labor-intensive sample pretreatment required to remove inhibitors that cause false-negative results in clinical samples is impractical for use in resource-limited areas. The aim was to develop a direct reverse-transcription quantitative PCR (dirRT-qPCR) assay for ZIKV diagnosis directly from clinical samples.The combination of inhibitor-tolerant polymerases, polymerase enhancers, and dirRT-qPCR conditions was optimized for various clinical samples including blood and serum. Sensitivity was evaluated with standard DNA spiked in simulated samples. Specificity was evaluated using clinical specimens of other infections such as dengue virus and chikungunya virus.High specificity and sensitivity were achieved, and the limit of detection (LOD) of the assay was 9.5 × 101 ZIKV RNA copies/reaction. The on-site clinical diagnosis of ZIKV required a 5 μl sample and the diagnosis could be completed within 2 h.This robust dirRT-qPCR assay shows a high potential for point-of-care diagnosis, and the primer–probe combinations can also be extended for other viral detection. It realizes the goal of large-scale on-site screening for viral infections and could be used for early diagnosis and the prevention and control of viral outbreaks.

Origin of the Zika virus revealed: a historical journey across the world.

Zika virus (ZIKV) is an arbovirus within the Flaviviridae family, the recent spread of which has promoted public concern. This study outlines the clinical features, potential for teratogenicity, diagnosis, and treatment of ZIKV infection. Zika virus is transmitted through the bite of an infected Stegomyia (= Aedes) mosquito, blood transfusion, sexual intercourse, and perinatal routes. Infection has been characterized as mildly symptomatic. Symptoms include mild fever, headache, arthralgia, myalgia, non-purulent conjunctivitis, and a pruritic maculopapular rash. It is rarely life-threatening, but both Guillain-Barré syndrome and fetal microcephaly have been reported. ZIKV belongs to the same family as bovine viral diarrhea virus, which causes hydrocephalus and microcephaly in newborn calves, and hepatitis C virus, which can be vertically transmitted in human pregnancies, and hence there remains concern for potential similarities. Diagnostic methods include polymerase chain reaction performed in blood samples during infection, and in urine and saliva. Pregnant women undergo antibody testing for immunoglobulin M. Treatment involves supportive care, and acetaminophen and antihistamines to control symptoms. Although there was no evidence of the circulation of ZIKV in the Western hemisphere prior to 2014, the global spread of Stegomyia aegypti and increases in urban populations and international travel have fostered its evolution. Adherence to current guidelines for the prevention of ZIKV transmission is especially relevant in regions experiencing ongoing outbreaks. Concern for microcephaly in newborns warrants further investigation into the potential long-term effects of ZIKV infection, especially in relation to reproductive health and mother-fetus transmission.

Zika Virus: From Obscurity to Potentially Devastating International Threat.

In the fall of 2015, an epidemic of microcephaly in newborn infants was reported in Brazil. Zika virus (ZIKV),5 a previously obscure arthropod-borne flavivirus in Africa transmitted by the Aedes aegypti mosquito, was identified as the suspected etiology. As pictures of severely affected infants began to appear in the news, the virus spread to additional countries in the Western hemisphere, and alarm grew. Travel alerts were issued and in some areas women were advised to defer pregnancy. Within a few months, the link of ZIKV infection to microcephaly was confirmed, and new information began and continues to emerge at a rapid pace. ZIKV is unique for an arbovirus, not only for its devastating outcomes in the fetus, but also for its potential for sexual transmission. Furthermore, it has become apparent that obtaining a rapid and accurate ZIKV diagnosis can be challenging. The public health, medical, and research communities are working with great focus and urgency to better understand transmission, pathogenesis, and outcome, to accurately diagnose, and to ultimately prevent human infections. Three experts currently involved in the response to ZIKV have taken the time to share their knowledge and their insights on what we have learned to date, even as the epidemic continues to unfold. ZIKV was first discovered in primates in the Zika Forest of Uganda in 1947. What changed to facilitate the recent explosive spread in humans? Laura Kramer: Intercontinental air travel, globalization, and urbanization facilitate spread of viruses and vectors to distant places. Furthermore, global warming and climate change are redefining the geographical distributions of mosquito vectors. In 2007, ZIKV spread from Africa and Southeast Asia to cause the first large outbreak in humans on the Pacific island of Yap, in the Federated States of Micronesia. Before this event, no outbreaks and only 14 cases of …

Advantage of urine based molecular diagnosis of Zika virus.

Zika virus (ZIKV) infection is an emerging global health concern, and diagnostic recommendations are currently developing based on new information. Several case or small sample size studies using both urine and blood samples suggest that ZIKV RNA can be detected at higher levels and for a longer time after onset of infection in urine compared to blood. We recommend that urine and serum collection for molecular testing be a standard part of evaluating patients for ZIKV infection, and that urine is a good alternative testing sample when blood collection is problematic.

Zika virus disease: a current review of the literature.

The massive pandemic of Zika virus (ZIKV) infection is spreading through South America, Central America, the Caribbean, and possibly the USA. It is the most recent of four surprising appearances of imperative arthropod-borne viral illnesses in the Western Hemisphere over the preceding 20years. The objective of this narrative review is to summarize the existing knowledge about the epidemiology, transmission, clinical manifestations, complications, replication, pathogenesis, diagnosis, and treatment and prevention of ZIKV infection. We used electronic databases to identify relevant published data regarding ZIKV in BOOLEAN and MeSH searches. This review concludes that the ZIKV predominantly circulates in arboreal mosquitoes (e.g., Aedes africanus) and wild primates. It rarely causes severe infection in humans, even in extremely enzootic regions. Currently, we do not have any efficacious drugs against ZIKV infection. However, there are virus-specific therapeutic targets, which may lead to the development of targeted anti-ZIKV drugs.

Detection of Zika virus by SYBR green one-step real-time RT-PCR

The ongoing Zika virus (ZIKV) outbreak has rapidly spread to new areas of Americas, which were the first transmissions outside its traditional endemic areas in Africa and Asia. Due to the link with newborn defects and neurological disorder, numerous infected cases throughout the world and various mosquito vectors, the virus has been considered to be an international public health emergency. In the present study, we developed a SYBR Green based one-step real-time RT-PCR assay for rapid detection of ZIKV. Our results revealed that the real-time assay is highly specific and sensitive in detection of ZIKV in cell samples. Importantly, the replication of ZIKV at different time points in infected cells could be rapidly monitored by the real-time RT-PCR assay. Specifically, the real-time RT-PCR showed acceptable performance in measurement of infectious ZIKV RNA. This assay could detect ZIKV at a titer as low as 1PFU/mL. The real-time RT-PCR assay could be a useful tool for further virology surveillance and diagnosis of ZIKV.

Isolation of Infective Zika Virus from Urine and Saliva of Patients in Brazil.

BackgroundZika virus (ZIKV) is an emergent threat provoking a worldwide explosive outbreak. Since January 2015, 41 countries reported autochthonous cases. In Brazil, an increase in Guillain-Barré syndrome and microcephaly cases was linked to ZIKV infections. A recent report describing low experimental transmission efficiency of its main putative vector, Ae. aegypti, in conjunction with apparent sexual transmission notifications, prompted the investigation of other potential sources of viral dissemination. Urine and saliva have been previously established as useful tools in ZIKV diagnosis. Here, we described the presence and isolation of infectious ZIKV particles from saliva and urine of acute phase patients in the Rio de Janeiro state, Brazil.Methodology/Principal FindingsNine urine and five saliva samples from nine patients from Rio de Janeiro presenting rash and other typical Zika acute phase symptoms were inoculated in Vero cell culture and submitted to specific ZIKV RNA detection and quantification through, respectively, NAT-Zika, RT-PCR and RT-qPCR. Two ZIKV isolates were achieved, one from urine and one from saliva specimens. ZIKV nucleic acid was identified by all methods in four patients. Whenever both urine and saliva samples were available from the same patient, urine viral loads were higher, corroborating the general sense that it is a better source for ZIKV molecular diagnostic. In spite of this, from the two isolated strains, each from one patient, only one derived from urine, suggesting that other factors, like the acidic nature of this fluid, might interfere with virion infectivity. The complete genome of both ZIKV isolates was obtained. Phylogenetic analysis revealed similarity with strains previously isolated during the South America outbreak.Conclusions/SignificanceThe detection of infectious ZIKV particles in urine and saliva of patients during the acute phase may represent a critical factor in the spread of virus. The epidemiological relevance of this finding, regarding the contribution of alternative non-vectorial ZIKV transmission routes, needs further investigation.

First International Workshop on Zika Virus Held by Oswaldo Cruz Foundation FIOCRUZ in Northeast Brazil March 2016 - A Meeting Report.

First International Workshop on Zika Virus Held by Oswaldo Cruz Foundation FIOCRUZ in Northeast Brazil March 2016 - A Meeting Report.

Zika Virus Infection: Current Concerns and Perspectives.

The Zika virus outbreaks highlight the growing importance need for a reliable, specific and rapid diagnostic device to detect Zika virus, as it is often recognized as a mild disease without being identified. Many Zika virus infection cases have been misdiagnosed or underreported because of the non-specific clinical presentation. The aim of this review was to provide a critical and comprehensive overview of the published peer-reviewed evidence related to clinical presentations, various diagnostic methods and modes of transmission of Zika virus infection, as well as potential therapeutic targets to combat microcephaly. Zika virus is mainly transmitted through bites from Aedes aegypti mosquito. It can also be transmitted through blood, perinatally and sexually. Pregnant women are advised to postpone or avoid travelling to areas where active Zika virus transmission is reported, as this infection is directly linked to foetal microcephaly. Due to the high prevalence of Guillain-Barre syndrome and microcephaly in the endemic area, it is vital to confirm the diagnosis of Zika virus. Zika virus infection had been declared as a public health emergency and of international concern by the World Health Organisation. Governments and agencies should play an important role in terms of investing time and resources to fundamentally understand this infection so that a vaccine can be developed besides raising awareness.

Ocular Findings in Infants With Microcephaly Associated With Presumed Zika Virus Congenital Infection in Salvador, Brazil

The Zika virus (ZIKV) has rapidly reached epidemic proportions, especially in northeastern Brazil, and has rapidly spread to other parts of the Americas. A recent increase in the prevalence of microcephaly in newborn infants and vision-threatening findings in these infants is likely associated with the rapid spread of ZIKV. To evaluate the ocular findings in infants with microcephaly associated with presumed intrauterine ZIKV infection in Salvador, Bahia, Brazil. Case series at a tertiary hospital. Twenty-nine infants with microcephaly (defined by a cephalic circumference of ≤32 cm) with a presumed diagnosis of congenital ZIKV were recruited through an active search and referrals from other hospitals and health unities. The study was conducted between December 1 and December 21, 2015. All infants and mothers underwent systemic and ophthalmic examinations from December 1 through December 21, 2015, in the Roberto Santos General Hospital, Salvador, Brazil. Anterior segment and retinal, choroidal, and optic nerve abnormalities were documented using a wide-field digital imaging system. The differential diagnosis included toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, syphilis, and human immunodeficiency virus, which were ruled out through serologic and clinical examinations. Ocular abnormalities associated with ZIKV. Twenty-three of 29 mothers (79.3%) reported suspected ZIKV infection signs and symptoms during pregnancy, 18 in the first trimester, 4 in the second trimester, and 1 in the third trimester. Of the 29 infants (58 eyes) examined (18 [62.1%] female), ocular abnormalities were present in 17 eyes (29.3%) of 10 children (34.5%). Bilateral findings were found in 7 of 10 patients presenting with ocular lesions, the most common of which were focal pigment mottling of the retina and chorioretinal atrophy in 11 of the 17 eyes with abnormalities (64.7%), followed by optic nerve abnormalities in 8 eyes (47.1%), bilateral iris coloboma in 1 patient (2 eyes [11.8%]), and lens subluxation in 1 eye (5.9%). Congenital infection due to presumed ZIKV exposure is associated with vision-threatening findings, which include bilateral macular and perimacular lesions as well as optic nerve abnormalities in most cases.

Zika Virus: A Roar After Years of Whispering.

The current extensive emergence and spread of Zika virus throughout South America, Central America, and the Caribbean is unprecedented, extraordinary, and potentially threatening global health.1 In light of the increased incidence of microcephaly and other neurological disorders believed to be linked to Zika virus in South America,2 the World Health Organization (WHO) has declared Zika a public health emergency of international concern on 1 February 2016. Zika virus is a single-stranded RNA virus in the family Flaviviridae and is related to dengue, yellow fever, West Nile, and Japanese encephalitis viruses.3 Zika virus was discovered incidentally in Uganda in 1947 in the course of mosquito and primate surveillance, and it was first described in humans in 1952 in Uganda and Tanzania. Since then, sporadic cases have been reported from Africa and Asia.4 The virus remained confined to a narrow niche in Africa and Asia until 2007 when the first documented outbreak occurred in the Federated States of Micronesia.4 This was followed by further outbreaks in the Pacific Island nations between 20135 and 2014, and now in Central and South America since 2015.6 Zika virus is mainly transmitted by the bite of an infected female Aedes aegypti mosquito.6 Other means of transmission (which require further scrutiny) include maternal-fetal transmission,7 sexual transmission,8 and transmission via blood through transfusion.9 Zika virus disease has been relatively a mild disease presenting with fever, rash, arthralgia, and conjunctivitis. The ongoing pandemic confirms that Zika is predominantly a mild or asymptomatic disease. However, in the last two years, Zika virus has gained attention after increasing concerns with its hypothesized association with Guillain-Barre syndrome in the French Polynesia and with birth defects, mainly microcephaly, in Brazil. During Zika virus epidemic in French Polynesia in 2013, the incidence of Guillain-Barre syndrome increased by twenty folds, raising the assumption of a potential implication of Zika.10 Of greater concern is the explosive Brazilian epidemic of microcephaly. Last month, Brazil reported a twenty-fold annual increase in cases of newborn babies with microcephaly.11 Additionally, ocular findings in few of these babies with microcephaly were described.12 It is crucially important to confirm or dismiss a causal link between Zika infection of pregnant women and the occurrence of microcephaly. However, there is currently no definitive proof of any causal relationship. If proven, Zika will be the first flavivirus to have teratogenic effects. It is challenging for scientists to understand why Zika is now behaving in this current explosive nature with widespread outbreaks and clinically alarming manifestations after over 60 years of quiescence. Mutations resulting in enhanced neurotropism and acquired population immunity in endemic areas are among some of the speculations, which will require a scientific inquest. Diagnosis of Zika virus is based on detection of the viral RNA by polymerase chain reaction (PCR) in serum.13 This test needs to be performed early in the acute phase of the illness to enable detection of viremia. Serum antibody testing can also be used for diagnosis but challenged with cross-reactivity with other arboviruses, mainly dengue virus.13 There is currently no specific antiviral agents that can be used to treat or prevent infection with Zika virus. There are no Zika vaccines in advanced development. Prevention of Zika is therefore directed at aggressive mosquito control, minimizing breeding sites and contact with Aedes mosquitoes.14 Pregnant women are advised to avoid travelling to areas with active Zika virus transmission. In Oman, the vector Aedes aegypti has been identified in limited parts of Dhofar region at a low scale as part of the entomological surveys conducted in the region between 2006 and 2014.15 This is being followed by extensive vector control efforts. In the event of virus introduction to the region, we predict that it is extremely unlikely to result in sustained transmission or outbreaks. This is largely due to very limited vector population and intensive vector control efforts in Oman. Close monitoring and community education on strategies to eliminate mosquitoes breeding sites are essential. Early recognition of imported cases of Zika is critical to prevent the introduction of the virus to Oman. We advocate screening for Zika virus in returned symptomatic travelers from areas with active Zika virus transmission. Additionally, symptomatic pregnant women with clear epidemiological links need be screened for Zika virus. Zika is still a pandemic in evolution, and many vital questions about it remain to be answered. Zika virus is truly a disturbing global threat necessitating prompt and coordinated global actions for stopping it from continue roaring.

Outbreak of Zika Virus

Zika virus (ZIKV) is a vector-borne flavivirus. It was initially identified in Uganda in 1947, and the first human infection was reported in Nigeria in 1953. Since 2015, ZIKV has been spreading rapidly in Brazil and the Americas. Given its general symptoms, ZIKV is considered to be a mild, febrile illness, although it is associated with severe neurologic complications. On February 1, 2016, the World Health Organization (WHO) declared a Public Health Emergency of International Concern (PHEIC). We conducted a review of the literature on the epidemiology and transmission, clinical manifestations, and diagnosis of ZIKV. Additionally, we introduce original literature on the current ZIKV outbreak in this review.

Pathogenesis, diagnostic challenges and treatment of zika virus disease in resource-limited settings.

The association of Zika virus (ZIKV) infection with congenital malformation and neurological sequelae has brought significant global concern. Consequently, the World Health Organization (WHO) declared it "a public health emergency of International concern" on 1 February, 2016. A critical review of its pathogenesis would lead to a better understanding of the clinical features and the neurological complications. This review is based on literature search in PubMed/Medline, Google Scholar and the WHO, http://www.who.int. This include all relevant articles written in English published through June 2018, with subject heading and keywords such as Zika, ZIKV, Zika pathogenesis, diagnosis of Zika, Zika Nigeria, Zika Africa and Zika resource-limited settings. Following ZIKV infection, viraemia ensues targeting primarily the monocytes for both the Asian and African strains. ZIKV infection by an African strain appears to be more pathogenic, in early pregnancy tends to result in spontaneous abortion. Whereas an Asian strain tends to be less pathogenic and more chronic, this allows the pregnancy to continue, ultimately resulting in congenital malformations. There is no routine laboratory diagnosis of ZIKV infection in resource-constrained countries. Serologic tests should be interpreted with caution since there can be cross-reactivity with other flaviviruses, especially in Africa where the burden of infection with flaviviruses is comparatively high. There is a paucity of well-equipped laboratories for comprehensive ZIKV diagnosis. It is imperative to strengthen the health systems, improve health workforce and diagnostic capacity of such settings.