Emergence of Epidemic Zika Virus Transmission and Congenital Zika Syndrome: Are Recently Evolved Traits to Blame?

ABSTRACT The mechanisms responsible for the dramatic emergence of Zika virus (ZIKV), accompanied by congenital Zika syndrome and Guillain-Barré syndrome (GBS), remain unclear. However, two hypotheses are prominent: (i) evolution for enhanced urban transmission via adaptation to mosquito vectors, or for enhanced human infection to increase amplification, or (ii) the stochastic introduction of ZIKV into large, naive human populations in regions with abundant Aedes aegypti populations, leading to enough rare, severe infection outcomes for their first recognition. Advances in animal models for human infection combined with improvements in serodiagnostics, better surveillance, and reverse genetic approaches should provide more conclusive evidence of whether mosquito transmission or human pathogenesis changed coincidentally with emergence in the South Pacific and the Americas. Ultimately, understanding the mechanisms of epidemic ZIKV emergence, and its associated syndromes, is critical to predict future risks as well as to target surveillance and control measures in key locations.

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International travelers and genomics uncover a ‘hidden’ Zika outbreak

10.1101/496901 ◽

2018 ◽

Cited By ~ 1

Author(s):

Nathan D. Grubaugh ◽

Sharada Saraf ◽

Karthik Gangavarapu ◽

Alexander Watts ◽

Amanda L. Tan ◽

...

Keyword(s):

Zika Virus ◽

Public Health Surveillance ◽

Mosquito Control ◽

Herd Immunity ◽

Virus Transmission ◽

The United States ◽

Control Measures ◽

Local Case ◽

Peak Transmission ◽

And Control

AbstractThe ongoing Zika epidemic in the Americas has challenged public health surveillance, response, and control systems. Even as the epidemic appears to be near its end in the Americas, it is unclear whether substantial Zika virus transmission may still be ongoing. This issue is exacerbated by large discrepancies in local case reporting and significant delays in detecting outbreaks due to surveillance gaps. To uncover locations with lingering outbreaks in the Americas, we investigated travel-associated Zika cases diagnosed in the United States and Europe to identify signatures of transmission dynamics that were not captured by local reporting. We found that a large and unreported Zika outbreak occurred in Cuba during 2017, a year after peak transmission in neighboring countries, with cases still appearing in 2018. By sequencing Zika virus from infected travelers, we show that the 2017 outbreak in Cuba was sparked by long-lived lineages of Zika virus introduced from multiple places in the Americas a year prior. Our data suggest that while aggressive mosquito control in Cuba may initially have been effective at mitigating Zika virus transmission, in the absence of vaccines, herd immunity, or strong international coordination, such control measures may need to be maintained to be effective. Our study highlights how Zika virus may still be ‘silently’ spreading in the Americas and provides a framework for more accurately understanding outbreak dynamics.

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Vectors, Hosts, and Control Measures for Zika Virus in the Americas

EcoHealth ◽

10.1007/s10393-017-1277-2 ◽

2017 ◽

Vol 14 (4) ◽

pp. 821-839 ◽

Cited By ~ 3

Author(s):

Sarah J. Thompson ◽

John M. Pearce ◽

Andrew M. Ramey

Keyword(s):

Zika Virus ◽

Control Measures ◽

And Control

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Times to Key Events in the Course of Zika Infection and their Implications for Surveillance: A Systematic Review and Pooled Analysis

10.1101/041913 ◽

2016 ◽

Cited By ~ 9

Author(s):

Justin Lessler ◽

Cassandra T. Ott ◽

Andrea C. Carcelen ◽

Jacob M. Konikoff ◽

Joe Williamson ◽

...

Keyword(s):

Systematic Review ◽

Blood Supply ◽

Zika Virus ◽

Blood Donation ◽

Case Reports ◽

Fold Increase ◽

Pooled Analysis ◽

Control Measures ◽

History Of ◽

And Control

Background Evidence suggests that Zika virus has driven a 10-fold increase in babies born with microcephaly in Brazil, prompting the WHO to declare a Public Health Emergency of International Concern. However, little is known about the natural history of infection. These data are critical for implementation of surveillance and control measures such as protecting the blood supply. Methods We conducted a systematic review and pooled analysis to estimate the distribution of times from Zika infection to symptom onset, seroconversion, and viral clearance, and analyzed their implications for surveillance and blood supply safety. Results Based on 25 case reports, we estimate the median incubation period of Zika virus infection is 5.9 days (95% CI: 4.4-7.6), and that 95% of cases will develop symptoms by 11.1 days post-infection (95% CI: 7.6-18.0). On average seroconversion occurs 9.0 days (95% CI, 7.0-11.6) after infection, and virus is detectable in blood for 9.9 days (95% CI: 6.8-21.4). In 5% of cases detectable virus persists for over 18.9 days (95% CI: 12.6-79.5). The baseline (no screening) risk of a blood donation being infected with Zika increases by approximately 1 in 10,000 for every 1 per 100,000 person-days increase in Zika incidence. Symptom based screening reduces this by 7% (RR 0.93, 93% CI 0.86-0.99), and antibody screening by 29% (RR 0.71, 95% CI: 0.28-0.88). Conclusions Symptom or antibody-based surveillance can do little to reduce the risk of Zika contaminated blood donations. High incidence areas may consider PCR testing to identify lots safe for use in pregnant women.

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Screening of Highly Expressed Mycobacterial Genes Identifies Rv3615c as a Useful Differential Diagnostic Antigen for the Mycobacterium tuberculosis Complex

Infection and Immunity ◽

10.1128/iai.00150-08 ◽

2008 ◽

Vol 76 (9) ◽

pp. 3932-3939 ◽

Cited By ~ 69

Author(s):

Ben Sidders ◽

Chris Pirson ◽

Philip J. Hogarth ◽

R. Glyn Hewinson ◽

Neil G. Stoker ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Significant Proportion ◽

Growth Conditions ◽

Control Measures ◽

Human Populations ◽

Infected Cattle ◽

Ifn Γ ◽

Mycobacterial Antigens ◽

And Control ◽

Differential Antigens

ABSTRACT Tuberculous infections caused by mycobacteria, especially tuberculosis of humans and cattle, are important both clinically and economically. Human populations can be vaccinated with Mycobacterium bovis bacille Calmette-Guérin (BCG), and control measures for cattle involving vaccination are now being actively considered. However, diagnostic tests based on tuberculin cannot distinguish between genuine infection and vaccination with BCG. Therefore, identification of differential diagnostic antigens capable of making this distinction is required, and until now sequence-based approaches have been predominant. Here we explored the link between antigenicity and mRNA expression level, as well as the possibility that we may be able to detect differential antigens by analyzing quantified global transcriptional profiles. We generated a list of 14 candidate antigens that are highly expressed in Mycobacterium tuberculosis and M. bovis under a variety of growth conditions. These candidates were screened in M. bovis-infected and naïve cattle for the ability to stimulate a gamma interferon (IFN-γ) response. We identified one antigen, Rv3615c, which stimulated IFN-γ responses in a significant proportion of M. bovis-infected cattle (11 of 30 cattle [37%] [P < 0.01]) but not in naïve or BCG-vaccinated animals. Importantly, the same antigen stimulated IFN-γ responses in a significant proportion of infected cattle that did not respond to the well-characterized mycobacterial antigens ESAT-6 and CFP-10. Therefore, use of the Rv3615c epitope in combination with previously described differential tests based on ESAT-6 and CFP-10 has the potential to significantly increase diagnostic sensitivity without reducing specificity in BCG-vaccinated populations.

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The effect of human mobility and control measures on the COVID-19 epidemic in China

10.1101/2020.03.02.20026708 ◽

2020 ◽

Cited By ~ 7

Author(s):

Moritz U.G. Kraemer ◽

Chia-Hung Yang ◽

Bernardo Gutierrez ◽

Chieh-Hsi Wu ◽

Brennan Klein ◽

...

Keyword(s):

Human Mobility ◽

Control Measures ◽

Human Populations ◽

Travel History ◽

Mobility Data ◽

Travel Restrictions ◽

State Interventions ◽

And Control ◽

The Impact

AbstractThe ongoing COVID-19 outbreak has expanded rapidly throughout China. Major behavioral, clinical, and state interventions are underway currently to mitigate the epidemic and prevent the persistence of the virus in human populations in China and worldwide. It remains unclear how these unprecedented interventions, including travel restrictions, have affected COVID-19 spread in China. We use real-time mobility data from Wuhan and detailed case data including travel history to elucidate the role of case importation on transmission in cities across China and ascertain the impact of control measures. Early on, the spatial distribution of COVID-19 cases in China was well explained by human mobility data. Following the implementation of control measures, this correlation dropped and growth rates became negative in most locations, although shifts in the demographics of reported cases are still indicative of local chains of transmission outside Wuhan. This study shows that the drastic control measures implemented in China have substantially mitigated the spread of COVID-19.

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Cluster containment strategy: addressing Zika virus outbreak in Rajasthan, India

BMJ Global Health ◽

10.1136/bmjgh-2018-001383 ◽

2019 ◽

Vol 4 (5) ◽

pp. e001383 ◽

Cited By ~ 2

Author(s):

Ruchi Singh ◽

Veenu Gupta ◽

Bharti Malhotra ◽

Sujeet Singh ◽

P Ravindran ◽

...

Keyword(s):

Zika Virus ◽

Virus Disease ◽

Virus Transmission ◽

Geographic Area ◽

Control Measures ◽

Surveillance Strategy ◽

North West ◽

High Prevalence ◽

Containment Strategy ◽

The Government

India is at risk of Zika virus transmission due to high prevalence of its vector Aedes aegypti. Rajasthan, a state in the north-west region of India, has also high prevalence of Aedes mosquito. First laboratory confirmed case of Zika virus disease in Rajasthan was reported on 21 September 2018 in Jaipur. The Government of Rajasthan quickly implemented a containment strategy to contain the outbreak and prevent further spread of this disease. Strategy included active human and mosquito surveillance, laboratory testing and sequencing of the virus, integrated vector control measures, intersectoral coordination, risk communication and social mobilisation, all in a predefined geographic area around the epicentre. Timely action with appropriate coordination at all levels with multiple stakeholders contained the outbreak successfully. In all, 159 confirmed cases were reported from in and around the 3 km containment zone in Shastri Nagar area of Jaipur City and routine surveillance. Following this, a specially developed laboratory-based surveillance strategy was put in place to ensure that the disease does not spread beyond the containment zone. No fresh case was reported subsequently within or beyond the containment zone.

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Zika Virus: A Basic Overview of an Emerging Arboviral Infection in the Western Hemisphere

Disaster Medicine and Public Health Preparedness ◽

10.1017/dmp.2016.43 ◽

2016 ◽

Vol 10 (5) ◽

pp. 707-712 ◽

Cited By ~ 12

Author(s):

Kelly G. Vest

Keyword(s):

Public Health ◽

Virus Infection ◽

Zika Virus ◽

Western Hemisphere ◽

Control Measures ◽

Historical Background ◽

World Health ◽

Zika Virus Infection ◽

Health Organization ◽

And Control

AbstractSince February 2015, Zika virus has spread throughout the Western Hemisphere, starting in Brazil. As of March 2016, autochthonous transmission has been reported in at least 31 countries or territories. For countries in the Americas, the spread of Zika virus, a previously unfamiliar disease, follows similar emerging infection introductions of West Nile virus and Chikungunya virus and their spread throughout the American continents and the Caribbean nations. The Pan American Health Organization and the World Health Organization have issued alerts and a Public Health Emergency of International Concern announcement related to the recent cluster of microcephaly cases and other neurological disorders in Brazil that are temporally associated with Zika virus, which highlights the possible adverse impact of viral infection. This article provides an overview of the Zika virus infection and presents the historical background of the virus, a description of the pathogen, the epidemiology and clinical spectrum of Zika virus infection, diagnosis and treatment approaches, and prevention and control measures. Understanding what is known about the virus and its clinical presentation will assist in prevention, detection, and response measures to reduce and control the spread of the virus throughout the Western Hemisphere. (Disaster Med Public Health Preparedness. 2016;page 1 of 6)

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Global RNAseq of ocular cells reveals gene dysregulation in both asymptomatic and with Congenital Zika Syndrome infants exposed prenatally to Zika virus

10.1101/2020.10.20.20214403 ◽

2020 ◽

Author(s):

Livia Rosa-Fernandes ◽

Amina Bedrat ◽

Maria Luiza B. dos Santos ◽

Ana Pinto ◽

E Lucena ◽

...

Keyword(s):

Gene Expression ◽

Zika Virus ◽

Clinical Signs ◽

Neuronal Cell ◽

Embryonic Cells ◽

Zikv Infection ◽

Gene Dysregulation ◽

Congenital Zika Syndrome ◽

Invasive Method ◽

And Control

AbstractIn 2015, Brazil reported an outbreak identified as Zika virus (ZIKV) infection associated with congenital abnormalities. To date, a total of 86 countries and territories have described evidence of Zika infection and recently the appearance of the African ZIKV lineage in Brazil highlights the risk of a new epidemic. The spectrum of ZIKV infection-induced alterations at both cellular and molecular levels is not completely elucidated. Here, we present for the first time the gene expression responses associated with prenatal ZIKV infection from ocular cells. We applied a recently developed non-invasive method (impression cytology) which use eye cells as a model for ZIKV studies. The ocular profiling revealed significant differences between exposed and control groups, as well as a different pattern in ocular transcripts from Congenital Zika Syndrome (CZS) compared to ZIKV-exposed but asymptomatic infants. Our data showed pathways related to mismatch repair, cancer, and PI3K/AKT/mTOR signaling and genes probably causative or protective in the modulation of ZIKV infection. Ocular cells revealed the effects of ZIKV infection on primordial neuronal cell genes, evidenced by changes in genes associated with embryonic cells. The changes in gene expression support an association with the gestational period of the infection and provide evidence for the resulting clinical and ophthalmological pathologies. Additionally, the findings of cell death- and cancer-associated deregulated genes raise concerns about the early onset of other potential pathologies including the need for tumor surveillance. Our results thus provide direct evidence that infants exposed prenatally to the Zika virus, not only with CZS but also without clinical signs (asymptomatic) express cellular and molecular changes with potential clinical implications.

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Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (COVID-19)

10.1101/2020.02.14.20023127 ◽

2020 ◽

Cited By ~ 111

Author(s):

Ruiyun Li ◽

Sen Pei ◽

Bin Chen ◽

Yimeng Song ◽

Tao Zhang ◽

...

Keyword(s):

Virus Transmission ◽

Control Measures ◽

Reproductive Number ◽

Force Of Infection ◽

Mobility Data ◽

Source Of Infection ◽

Travel Restrictions ◽

Novel Coronavirus ◽

And Control ◽

Epidemiological Characteristics

AbstractBackgroundEstimation of the fraction and contagiousness of undocumented novel coronavirus (COVID-19) infections is critical for understanding the overall prevalence and pandemic potential of this disease. Many mild infections are typically not reported and, depending on their contagiousness, may support stealth transmission and the spread of documented infection.MethodsHere we use observations of reported infection and spread within China in conjunction with mobility data, a networked dynamic metapopulation model and Bayesian inference, to infer critical epidemiological characteristics associated with the emerging coronavirus, including the fraction of undocumented infections and their contagiousness.ResultsWe estimate 86% of all infections were undocumented (95% CI: [82%-90%]) prior to the Wuhan travel shutdown (January 23, 2020). Per person, these undocumented infections were 52% as contagious as documented infections ([44%-69%]) and were the source of infection for two-thirds of documented cases. Our estimate of the reproductive number (2.23; [1.77-3.00]) aligns with earlier findings; however, after travel restrictions and control measures were imposed this number falls considerably.ConclusionsA majority of COVID-19 infections were undocumented prior to implementation of control measures on January 23, and these undocumented infections substantially contributed to virus transmission. These findings explain the rapid geographic spread of COVID-19 and indicate containment of this virus will be particularly challenging. Our findings also indicate that heightened awareness of the outbreak, increased use of personal protective measures, and travel restriction have been associated with reductions of the overall force of infection; however, it is unclear whether this reduction will be sufficient to stem the virus spread.

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Using simulation Technology to Analyze the COVID-19 Epidemic in Changsha, Hunan Province, China

10.21203/rs.3.rs-67564/v1 ◽

2020 ◽

Author(s):

Nan Zhou ◽

Guoqun LI ◽

Tong LI ◽

Weitong LI ◽

Mengxiang CHEN ◽

...

Keyword(s):

Virus Transmission ◽

Control Measures ◽

Hunan Province ◽

Contact Rate ◽

Simulation Technology ◽

Simulation Results ◽

Prevention And Control Measures ◽

And Control ◽

The Impact ◽

Infectious Disease Dynamics

Abstract This study mainly uses simulation technology to simulate the COVID-19 epidemic in Changsha, Hunan Province, China, and analyze the impact of different prevention and control measures on the epidemic. we Collect the information of all COVID-19 patients in Changsha from January 21, 2020 to March 14, 2020 and relevant policies during the COVID-19 epidemic in Changsha. Established the SEIAR infectious disease dynamics model under natural conditions, and added isolation measures on this basis. Using Anylogic8.5, the COVID-19 epidemic in Changsha City was simulated under various conditions based on the established model.In this study we find that There were 242 COVID-19 patients in Changsha. including 121 males (50%) and 121 females (50%).Most cases occurred between February 6 and February 16. Through the calculation of the Rt during the epidemic in Changsha, it is found that it is reasonable to resume work on February 8, because the Rt value of Changsha dropped below 1 at this time.The simulation results show that reducing the contact rate of residents and reducing the success rate of virus transmission (wearing masks, disinfection, etc.) can effectively prevent the spread of COVID-19 and significantly reduce the number of peak patients.We believe that the disease is mainly spread by the respiratory tract. Therefore, the simulation results show that whether in the early or mid-stage of the epidemic, quarantining the names of residents or reducing the contact rate of residents is very effective in controlling the COVID-19 epidemic.

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