Prevention and Control Strategies to Counter ZIKA Epidemic

Public Health Strategies in the Face of Crisis: A Comprehensive Review of the Zika Outbreak in India

This review provides a comprehensive analysis of the public health strategies employed during the Zika outbreak in India, focusing on the identification, surveillance, and containment efforts. The multifaceted approach, including vector control measures, healthcare infrastructure enhancement, and public communication strategies, played a pivotal role in mitigating the impact of the virus. Government policies and international collaborations emerged as influential factors, underscoring the significance of a coordinated response to infectious disease crises. The study emphasizes the importance of ongoing vigilance and preparedness in public health systems, acknowledging the dynamic nature of emerging infectious diseases. The Zika outbreak in India serves as a valuable case study, offering insights into the strengths and weaknesses of crisis management responses. As the global community faces ongoing health challenges, the lessons learned from this review contribute to refining strategies, improving coordination, and fostering a proactive and resilient approach to safeguarding public health.

Dengue, West Nile, and Zika Viruses: Potential Novel Antiviral Biologics Drugs Currently at Discovery and Preclinical Development Stages

Dengue, West Nile and Zika viruses are vector-borne flaviviruses responsible for numerous disease outbreaks in both Hemispheres. Despite relatively low mortality, infection may lead to potentially severe situations such as (depending on the virus): hypovolemic shock, encephalitis, acute flaccid paralysis, Guillain-Barré syndrome, congenital malformations (e.g., microcephaly) and, in some situations, death. Moreover, outbreaks also have major socioeconomic repercussions, especially in already vulnerable societies. Thus far, only generic symptoms relief is possible, as there are no specific treatments available yet. Dengvaxia was the world's first dengue vaccine. However, it is not fully effective. Prophylactic approaches against West Nile and Zika viruses are even more limited. Therefore, therapeutic strategies are required and will be discussed hereafter. We will first briefly present these viruses' epidemiology, life cycle and structure. Then, we introduce the clinical presentation, diagnosis approaches and available vaccines. Finally, we list and discuss promising compounds at discovery and preclinical development stages already deposited at the GlobalData database and divided into three main types, according to therapeutic molecule: antibody-based, peptide-based molecules and, other compounds. To conclude, we discuss and compare promising developments, useful for future therapies against these three flaviviruses of major concern to human health.

Borderline microscopic organism and lockdown impacted across the borders-global shakers

Viruses are the potential cause of several diseases including novel corona virus-19, flu, small pox, chicken pox, acquired immunodeficiency syndrome, severe acute respiratory syndrome etc. The objectives of this review article are to summarize the reasons behind the epidemics caused by several emerging viruses and bacteria, how to control the infection and preventive strategies. We have explained the causes of epidemics along with their preventive measures, the impact of lockdown on the health of people and the economy of a country. Several reports have revealed the transmission of infection during epidemic from the contact of an infected person to the public that can be prevented by implementing the lockdown by the government of a country. Though lockdown has been considered as one of the significant parameters to control the diseases, however, it has some negative consequences on the health of people as they can be more prone to other ailments like obesity, diabetes, cardiac problems etc. and drastic decline in the economy of a country. Therefore, the transmission of diseases can be prevented by warning the people about the severity of diseases, avoiding their public transportation, keeping themselves isolated, strictly following the guidelines of lockdown and encouraging regular exercise.

Cardiovascular Complications in Major 21st Century Viral Epidemics and Pandemics: an Insight into COVID-19

There have many major history-defining epidemics and pandemics in the 21st century. It is well known that acute infections can cause cardiovascular (CV) complications, especially in those with underlying cardiac disease. The variation in rates and types of CVD complications in major 21st century epidemics and pandemics varies greatly. The coronavirus disease 2019 (COVID-19) pandemic has caused the turmoil of the century and has COVID-19 has resulted in substantial human and economic loss. The novelty of COVID-19 and emerging CV effects is a new entity. In this review, we discuss the major epidemics and pandemics of the 21st century and associated CVD complications.

Zika virus infection in pregnant women and their children: A review

Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) transmitted primarily by Aedes mosquitoes. ZIKV can be transmitted to humans by non-vector borne mechanisms such as sexual intercourse, maternal-foetal transmission or blood transfusion. In 2015, ZIKV emerged in the Americas, and spread to 87 countries and territories with autochthonous transmission, distributed across four of the six WHO regions. Most ZIKV infections in pregnancy are asymptomatic, but mother to child transmission of the virus can occur in 20 to 30% of cases and cause severe foetal and child defects. Children exposed to ZIKV while in utero might develop a pattern of structural anomalies and functional disabilities secondary to central nervous system damage, known as congenital Zika syndrome, and whose most common clinical feature is microcephaly. Normocephalic children born to mothers with ZIKV infection in pregnancy, and with no observable Zika-associated birth defects, may also present with later neurodevelopmental delay or post-natal microcephaly. Screening and detection of ZIKV infection in pregnancy is essential, because most women with ZIKV infection are asymptomatic and clinical manifestations are non-specific. However, the diagnosis of ZIKV infection poses multiple challenges due to limited resources and scarce laboratory capabilities in most affected areas, the narrow window of time that the virus persists in the bloodstream, the large proportion of asymptomatic infections, and the cross-reactivity with other flaviviruses such as Dengue virus (DENV). Molecular methods (RT-PCR) are the most reliable tool to confirm ZIKV infection, as serodiagnosis requires confirmation with neutralization tests in case of inconclusive or positive serology results. Prenatal ultrasound assessment is essential for monitoring foetal development and early detection of possible severe anomalies. A mid- and long-term follow-up of children exposed to ZIKV while in utero is necessary to promptly detect clinical manifestations of possible neurological impairment. Tweetable abstract: Zika virus infection during pregnancy is a cause of pregnancy loss and disability in children. Protection against mosquito bites, access to sexual and reproductive health services, prompt screening and detection of ZIKV infection in pregnancy, and prenatal ultrasound monitoring are key control strategies whilst a vaccine is not available.

Dengue and human health: A global scenario of its occurrence, diagnosis and therapeutics

Dengue is one of the highest and rapidly spreading vector-borne viral diseases with high mortality rates. The infection causes acute febrile illness, a major public health concern in the tropics and subtropics globally. The disease is caused by an RNA virus that belongs to the Flaviviridae family. The virus is transferred to humans by the mosquito vector called Aedvrves aegypti, which is the cause of new prevalent sicknesses worldwide. These vector-borne viral diseases spread very fast and pose public health and economic challenges that deemed various prevention and control techniques. The Flavivirus genus consists of five different types of viruses starting from DENV-1 to DENV-5. Thus, the present review focuses on the origin of the virus, how the Dengue virus can be detected, infection, the morphology of the virus, its classifications as proposed by ICTV, the replication and genome of the dengue virus, translation, receptor binding, and some vaccine trial volunteers. In addition, it highlights the current challenges and limitations of effective dengue treatment.

Knowledge of Zika Virus Transmission and Its Prevention among High-Risk Pregnant Women in Brazil

Recent outbreaks of Zika virus (ZIKV) infection highlight the urgent need to evaluate the efficacy of current public health measures to educate susceptible groups about how to prevent infection, modes of viral transmission, and consequences of infection. We performed a cross-sectional study in the city of Jundiaí, São-Paulo, from March 2016 to August 2017. In 315 high-risk pregnant women we evaluated the rate of ZIKV infection, knowledge of pathways of ZIKV transmission, and the use of protective measures. Data were analyzed and correlated with sociodemographic variables. The rate of ZIKV infection was 10.8%. ZIKV transmission by mosquitoes was the best-known means of virus acquisition, while transmission of ZIKV by sexual intercourse as well as mother–fetus transmission was known by less than half of the women. The use of insect repellent, reported by 53% of participants, was correlated with higher education and personal directives from health professionals. Condom use was reported by 19.5% of subjects. Improved strategies to increase awareness of ZIKV infection and its consequences, designed to appeal to specific, targeted populations, are clearly necessary to more accurately prevent the spread of this infection and diminish adverse consequences in the pregnant population.

Zika virus: an emerging challenge to public health worldwide

Zika virus (ZIKV) is a mosquito-borne virus that was first isolated from Zika forest, Uganda, in 1947. Since its inception, major and minor outbreaks have been documented from several parts of world. Aedes spp. mosquitoes are the primary vectors of ZIKV, but the virus can also be transmitted through sexual practices, materno-fetal transmission, and blood transfusion. The clinical presentations of symptomatic ZIKV infections are similar to dengue and chikungunya, including fever, headache, arthralgia, retro-orbital pain, conjunctivitis, and rash. ZIKV often causes mild illness in the majority of cases, but in some instances, it is linked with congenital microcephaly and autoimmune disorders like Guillain-Barré syndrome. The recent Indian ZIKV outbreak suggests that the virus is circulating in the South East Asian region and may cause new outbreaks in future. At present, no specific vaccines or antivirals are available to treat ZIKV, so management and control of ZIKV infections rely mostly on preventive measures.

Zika Virus and Neurologic Disease

Zika virus (ZIKV) is an arthropod-borne virus that belongs to the Flaviviridae family. Although most cases are mild or go undetected, rare severe neurologic effects, including congenital ZIKV syndrome (CZS) and Guillain-Barré syndrome, have been identified. The serious neurologic complications associated with ZIKV prompted the declaration of the public health emergency of international concern by the World Health Organization. Overall, transmission occurred throughout South and Central America as well as the Caribbean, affecting 48 countries and territories from March 2015 to March 2017. Long-term management of CZS requires a comprehensive combination of supportive services throughout early development.

Support for vector control strategies in the United States during the Zika outbreak in 2016: The role of risk perception, knowledge, and confidence in government

Limiting the spread and impact of Zika was a major global priority in 2016, which required a variety of vector control measures. The success of vector control campaigns is varied and often dependent on public or political will. This paper examines the change over time in the United States population's support for vector control and the factors that predicted support for three vector control strategies (i.e., indoor spraying, outdoor spraying, and use of larvacide tablets) during the 2016 Zika outbreak in the United States. Data is from a nationally representative random digit dial sample conducted at three time points in 2016. Bivariate and multivariate regression analyses were used, treating data as a pooled cross-sectional sample. Results show public support for vector control strategies depends on both perceived risk for disease and knowledge of disease characteristics, as well is confidence in government to prevent the threat. Support varied based on vector control method: indoor spraying, aerial spraying, and use of larvacide tables. Results can aide public health officials in implementing effective vector control campaigns depending on the vector control strategy of choice. Results have implications for ways to design effective prevention campaigns in future emerging infectious disease threats.

Differences Between Florida and the Rest of the United States in Response to Local Transmission of the Zika Virus: Implications for Future Communication Campaigns

For those at risk for Zika virus infection, prevention requires an approach that includes individual, interpersonal, and community-level support for behavior change. In August 2016, the announcement of local Zika transmission in Florida provided an opportunity to determine whether Zika-related knowledge, attitudes, and behaviors might be affected differentially in Florida compared to the rest of the nation. From August 8-October 3, 2016, we conducted nationally representative weekly surveys (N = 12,236), oversampling Florida residents, measuring Zika virus news exposure, knowledge about transmission and prevention of the infection, and attitudes and behaviors toward prevention. We tested two classes of models: those focused on individual Zika risk perceptions (e.g., protection motivation theory) and one focused on community action beyond those directly at risk (social consensus model). Analyses assessed differences between Florida and the rest of the nation by survey week. Consistent with both models, Floridians demonstrated significantly higher levels of perceived susceptibility and knowledge, more positive attitudes toward Zika virus prevention, and higher likelihood of engaging in protective behavior than non-Floridians. Consistent with theories of individual risk perception, response was greater among respondents who saw themselves at risk of infection. However, consistent with the SCM, irrespective of personal risk, response was greater among Floridians. Nevertheless, more than half of the public took no direct action to prevent the spread of Zika. Communities at increased risk for a novel infection such as Zika may quickly acquire Zika-related knowledge, attitudes, and behavior, but large-scale community-wide response might be difficult without further community-level public education.

Global spatial assessment of Aedes aegypti and Culex quinquefasciatus: a scenario of Zika virus exposure

Zika virus (ZIKV) is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. Recent scientific evidence on Culex quinquefasciatus has suggested its potential as a vector for ZIKV, which may change the current risk zones. We aimed to quantify the world population potentially exposed to ZIKV in a spatially explicit way, considering the primary vector (A. aegypti) and the potential vector (C. quinquefasciatus). Our model combined species distribution modelling of mosquito species with spatially explicit human population data to estimate ZIKV exposure risk. We estimated the potential global distribution of C. quinquefasciatus and estimated its potential interaction zones with A. aegypti. Then we evaluated the risk zones for ZIKV considering both vectors. Finally, we quantified and compared the people under risk associated with each vector by risk level, country and continent. We found that C. quinquefasciatus had a more temperate distribution until 42° in both hemispheres, while the risk involving A. aegypti is concentrated mainly in tropical latitudes until 35° in both hemispheres. Globally, 4.2 billion people are under risk associated with ZIKV. Around 2.6 billon people are under very high risk associated with C. quinquefasciatus and 1 billion people associated with A. aegypti. Several countries could be exposed to ZIKV, which emphasises the need to clarify the competence of C. quinquefasciatus as a potential vector as soon as possible. The models presented here represent a tool for risk management, public health planning, mosquito control and preventive actions, especially to focus efforts on the most affected areas.

Knowledge, Attitudes, and Practices about Zika among a University Community Located in an Endemic Zone in Mexico

To assess the knowledge, attitudes, and practices about the Zika virus in both students and workers at the University of Veracruz, an online survey was conducted. The participants were divided into two groups: one according to sex, the other according to whether they were workers or students. Their answers were classified into knowledge, attitudes, and practices and they were rated as low, medium, and high. The results showed that knowledge about Zika prevailing among the university population is considered as medium in 79.4% of the study population. Most respondents know that the mosquito spreads the Zika virus (98.8%) and the clinical characteristics, while sexual transmission by the virus is little known (36.85%). Both the univariate analysis (OR (CI5) 0.227 (0.070⁻0.735), p = 0.013] and multivariate analysis (OR (CI95) 0.234 (0.071⁻778), p = 0.018] showed that belonging to the health sciences area is related to having a greater knowledge about Zika. Despite the existing knowledge, a low level of prevention practices prevails in the whole community (55%). A medium level of knowledge about Zika prevailed, while proper implementation of preventive measures for Zika is low, despite the fact that the state of Veracruz-the place where the University is located-is an endemic area.

An Update on Sexual Transmission of Zika Virus

Zika virus (ZIKV) is a single-stranded RNA virus belonging to the arthropod-borne flaviviruses (arboviruses) which are mainly transmitted by blood-sucking mosquitoes of the genus Aedes. ZIKV infection has been known to be rather asymptomatic or presented as febrile self-limited disease; however, during the last decade the manifestation of ZIKV infection has been associated with a variety of neuroimmunological disorders including Guillain–Barré syndrome, microcephaly and other central nervous system abnormalities. More recently, there is accumulating evidence about sexual transmission of ZIKV, a trait that has never been observed in any other mosquito-borne flavivirus before. This article reviews the latest information regarding the latter and emerging role of ZIKV, focusing on the consequences of ZIKV infection on the male reproductive system and the epidemiology of human-to-human sexual transmission.

Prevention and Control Strategies to Counter Zika Virus, a Special Focus on Intervention Approaches against Vector Mosquitoes-Current Updates

Zika virus (ZIKV) is the most recent intruder that acquired the status of global threat creating panic and frightening situation to public owing to its rapid spread, attaining higher virulence and causing complex clinical manifestations including microcephaly in newborns and Guillain Barré Syndrome. Alike other flaviviruses, the principal mode of ZIKV transmission is by mosquitoes. Advances in research have provided reliable diagnostics for detecting ZIKV infection, while several drug/therapeutic targets and vaccine candidates have been identified recently. Despite these progresses, currently there is neither any effective drug nor any vaccine available against ZIKV. Under such circumstances and to tackle the problem at large, control measures of which mosquito population control need to be strengthened following appropriate mechanical, chemical, biological and genetic control measures. Apart from this, several other known modes of ZIKV transmission which have gained importance in recent past such as intrauterine, sexual intercourse, and blood-borne spread need to be checked and kept under control by adopting appropriate precautions and utmost care during sexual intercourse, blood transfusion and organ transplantation. The virus inactivation by pasteurization, detergents, chemicals, and filtration can effectively reduce viral load in plasma-derived medicinal products. Added to this, strengthening of the surveillance and monitoring of ZIKV as well as avoiding travel to Zika infected areas would aid in keeping viral infection under check. Here, we discuss the salient advances in the prevention and control strategies to combat ZIKV with a focus on highlighting various intervention approaches against the vector mosquitoes of this viral pathogen along with presenting an overview regarding human intervention measures to counter other modes of ZIKV transmission and spread. Additionally, owing to the success of vaccines for a number of infections globally, a separate section dealing with advances in ZIKV vaccines and transmission blocking vaccines has also been included.

Advances in Diagnosis, Surveillance, and Monitoring of Zika Virus: An Update

Zika virus (ZIKV) is associated with numerous human health-related disorders, including fetal microcephaly, neurological signs, and autoimmune disorders such as Guillain-Barré syndrome (GBS). Perceiving the ZIKA associated losses, in 2016, the World Health Organization (WHO) declared it as a global public health emergency. In consequence, an upsurge in the research on ZIKV was seen around the globe, with significant attainments over developing several effective diagnostics, drugs, therapies, and vaccines countering this life-threatening virus at an early step. State-of-art tools developed led the researchers to explore virus at the molecular level, and in-depth epidemiological investigations to understand the reason for increased pathogenicity and different clinical manifestations. These days, ZIKV infection is diagnosed based on clinical manifestations, along with serological and molecular detection tools. As, isolation of ZIKV is a tedious task; molecular assays such as reverse transcription-polymerase chain reaction (RT-PCR), real-time qRT-PCR, loop-mediated isothermal amplification (LAMP), lateral flow assays (LFAs), biosensors, nucleic acid sequence-based amplification (NASBA) tests, strand invasion-based amplification tests and immune assays like enzyme-linked immunosorbent assay (ELISA) are in-use to ascertain the ZIKV infection or Zika fever. Herein, this review highlights the recent advances in the diagnosis, surveillance, and monitoring of ZIKV. These new insights gained from the recent advances can aid in the rapid and definitive detection of this virus and/or Zika fever. The summarized information will aid the strategies to design and adopt effective prevention and control strategies to counter this viral pathogen of great public health concern.

Discovery of a non-nucleoside RNA polymerase inhibitor for blocking Zika virus replication through in silico screening

Zika virus (ZIKV), an emerging arbovirus, has become a major human health concern globally due to its association with congenital abnormalities and neurological diseases. Licensed vaccines or antivirals against ZIKV are currently unavailable. Here, by employing a structure-based approach targeting the ZIKV RNA-dependent RNA polymerase (RdRp), we conducted in silico screening of a library of 100,000 small molecules and tested the top ten lead compounds for their ability to inhibit the virus replication in cell-based in vitro assays. One compound, 3-chloro-N-[({4-[4-(2-thienylcarbonyl)-1-piperazinyl]phenyl}amino)carbonothioyl]-1-benzothiophene-2-carboxamide (TPB), potently inhibited ZIKV replication at sub-micromolar concentrations. Molecular docking analysis suggests that TPB binds to the catalytic active site of the RdRp and therefore likely blocks the viral RNA synthesis by an allosteric effect. The IC₅₀ and the CC₅₀ of TPB in Vero cells were 94 nM and 19.4 μM, respectively, yielding a high selective index of 206. In in vivo studies using immunocompetent mice, TPB reduced ZIKV viremia significantly, indicating TPB as a potential drug candidate for ZIKV infections.

U.S. pregnant women's knowledge and attitudes about behavioral strategies and vaccines to prevent Zika acquisition

INTRODUCTION

Zika virus infection during pregnancy can cause significant infant morbidity. Little is known about pregnant women's attitudes regarding behavioral strategies and hypothetical vaccination to prevent Zika infections and sequelae.

METHODS

Pregnant women across the United States (N = 362) completed an online questionnaire regarding attitudes about Zika, including six behavioral prevention strategies (i.e., abstaining from sex, using condoms, not traveling to an area with Zika, their partner not traveling into an area with Zika, using mosquito repellant, wearing long pants and sleeves) and vaccination.

RESULTS

Most women (91%) were married/living with the baby's father, 65% were non-Hispanic White, and 71% had been pregnant. Seventy-four percent were worried about Zika, while 30% thought they were knowledgeable about Zika. The mean knowledge score was 5.0 out of 8 (SD = 2.09), and the mean behavioral strategies score was 4.9 out of 12 (SD = 3.7) with a range of 0 (none would be hard to do) to 12 (all would be hard to do). In a multivariable model, having had a sexually transmitted infection, living/traveling in an area with Zika, and worrying about Zika were significantly related to reporting behavioral strategies as hard to do. Seventy-two percent would be willing to be vaccinated. In the multivariable model, living/traveling in an area with Zika, believing they knew a lot about Zika, worrying about Zika, and considering Zika vaccine development as important were significantly associated with willingness to get vaccinated.

CONCLUSIONS

Pregnant women were worried about Zika, yet had gaps in their factual knowledge. Most women reported they would get vaccinated if a vaccine was available. Pregnant women who reported themselves as vulnerable (being worried, having lived in or traveled to a Zika area) were more likely to view behavioral strategies as hard to do and to accept vaccination.

Culex quinquefasciatus mosquitoes do not support replication of Zika virus

The rapid spread of Zika virus (ZIKV) in the Americas raised many questions about the role of Culex quinquefasciatus mosquitoes in transmission, in addition to the key role played by the vector Aedes aegypti. Here we analysed the competence of Cx. quinquefasciatus (with or without Wolbachia endosymbionts) for a ZIKV isolate. We also examined the induction of RNA interference pathways after viral challenge and the production of small virus-derived RNAs. We did not observe any infection nor such small virus-derived RNAs, regardless of the presence or absence of Wolbachia. Thus, Cx. quinquefasciatus does not support ZIKV replication and Wolbachia is not involved in producing this phenotype. In short, these mosquitoes are very unlikely to play a role in transmission of ZIKV.

Zika virus: what, where from and where to?

The significance of Zika virus as a clinically significant flavivirus has previously been under-recognised, until extensive outbreaks in Yap in 2007, French Polynesia in 2013 and the Americas since 2015. Although Zika virus infection is commonly asymptomatic or mild, emerging evidence suggests a strong link to microcephaly in babies and Guillain-Barré syndrome in adults. This article reviews the epidemiology, geographic distribution, basic virology, transmission, clinical presentation, potential complications, laboratory diagnosis, treatment and prevention of Zika virus infection. Education on mosquito avoidance measures and vector control efforts currently remain key to reducing risk of transmission, whilst further research is underway to develop antiviral therapies and vaccines.

Perceptions of Community Risk and Travel During Pregnancy in an Area of Zika Transmission

Introduction

Between June 2016 and August 2016, the first cases of the Zika transmission were reported in Miami, FL, US. Since then, travel advisories have been issued by the Centers for Disease Control and Prevention (CDC) to avoid travel to Florida. Women that are of childbearing age or pregnant are the populations most vulnerable to Zika infection because birth defects can occur in infants born to infected mothers. Till date, there are no studies assessing the perception of the community risk of Zika in pregnant women residing in an affected region such as Miami.

Methods

A cross-sectional design was utilized for this study. The survey included questions assessing community risk and travel perceptions. Surveys were distributed in the antenatal clinics at the University of Miami Hospital and the Jackson Memorial Hospital.

Results

A total of 85 women were surveyed between January 27, 2016 and March 3, 2017. Of the surveyed women, 92.6 percent believed Zika is an important issue in their community, 85.9 percent reported a change in behavior because of Zika, 26.9 percent believed they can get Zika at their location, and 13.9 percent considered moving away from Florida because of Zika. 

Conclusion

Despite the majority of women believing Zika is an important issue in their community, only one-fourth believed they could get Zika in Miami. Efforts to educate pregnant women in affected areas about preventive measures against the Zika infection should be undertaken. Further studies comparing the perceptions of community risks and travel behaviors in other affected areas are warranted.