The rise of Zika infection and microcephaly: what can we learn from a public health emergency?

Temporal variations in international air travel: implications for modelling the spread of infectious diseases

BACKGROUND

The international flight network creates multiple routes by which pathogens can quickly spread across the globe. In the early stages of infectious disease outbreaks, analyses using flight passenger data to identify countries at risk of importing the pathogen are common and can help inform disease control efforts. A challenge faced in this modelling is that the latest aviation statistics (referred to as contemporary data) are typically not immediately available. Therefore, flight patterns from a previous year are often used (referred to as historical data). We explored the suitability of historical data for predicting the spatial spread of emerging epidemics.

METHODS

We analysed monthly flight passenger data from the International Air Transport Association to assess how baseline air travel patterns were affected by outbreaks of Middle East respiratory syndrome (MERS), Zika and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) over the past decade. We then used a stochastic discrete time susceptible-exposed-infected-recovered (SEIR) metapopulation model to simulate the global spread of different pathogens, comparing how epidemic dynamics differed in simulations based on historical and contemporary data.

RESULTS

We observed local, short-term disruptions to air travel from South Korea and Brazil for the MERS and Zika outbreaks we studied, whereas global and longer-term flight disruptions occurred during the SARS-CoV-2 pandemic. For outbreak events that were accompanied by local, small and short-term changes in air travel, epidemic models using historical flight data gave similar projections of the timing and locations of disease spread as when using contemporary flight data. However, historical data were less reliable to model the spread of an atypical outbreak such as SARS-CoV-2, in which there were durable and extensive levels of global travel disruption.

CONCLUSION

The use of historical flight data as a proxy in epidemic models is an acceptable practice, except in rare, large epidemics that lead to substantial disruptions to international travel.

A legal mapping of 48 WHO member states' inclusion of public health emergency of international concern, pandemic, and health emergency terminology within national emergency legislation in responding to health emergencies

WHO has determined a public health emergency of international concern (PHEIC) seven times, and beyond this nomenclature declared COVID-19 to be a pandemic. Under the International Health Regulations (IHR), and through their operationalisation in the joint external evaluation (JEE), governments are urged to create suitable legislation to be able to enact a response to a public health emergency. Whether the pandemic declaration had a greater effect than a PHEIC in encouraging goverments to act, however, remains conjecture, as there is no systemic analysis of what each term means in practice and whether either has meaningful legal implications at the national level. We undertook a legal scoping review to assess the utilisation of PHEIC and pandemic language within national legislation in 28 WHO member states. Data were collected from national websites, JEE reviews, COVID Analysis and Mapping of Policies Tool, Natlex, and Oxford Compendium of National Legal Responses to COVID-19. We found that only 16% of countries have any reference to the PHEIC in national legislation and 37·5% of countries reference the term pandemic. This finding paints a weakened picture of the IHR and PHEIC mechanisms. Having such legalese enshrined in legislation might enhance the interaction between WHO determining a PHEIC or declaring a pandemic and resulting action to mitigate transnational spread of disease and enhance health security. Given the ongoing negotiations at WHO in relation to the amendments to the IHR and creation of the pandemic accord, both of which deal with this declaratory power of the PHEIC and pandemic language, negotiators should understand the possible implications of any changes to these proclamations at the national level and for global health security.

Insights into the structure, functional perspective, and pathogenesis of ZIKV: an updated review

Zika virus (ZIKV) poses a serious threat to the entire world. The rapid spread of ZIKV and recent outbreaks since 2007 have caused worldwide concern about the virus. Diagnosis is complicated because of the cross-reactivity of the virus with other viral antibodies. Currently, the virus is diagnosed by molecular techniques such as RT-PCR and IgM-linked enzyme immunoassays (MAC-ELISA). Recently, outbreaks and epidemics have been caused by ZIKV, and severe clinical symptoms and congenital malformations have also been associated with the virus. Although most ZIKV infections present with a subclinical or moderate flu-like course of illness, severe symptoms such as Guillain-Barre syndrome in adults and microcephaly in children of infected mothers have also been reported. Because there is no reliable cure for ZIKV and no vaccine is available, the public health response has focused primarily on preventing infection, particularly in pregnant women. A comprehensive approach is urgently needed to combat this infection and stop its spread and imminent threat. In view of this, this review aims to present the current structural and functional viewpoints, structure, etiology, clinical prognosis, and measures to prevent this transmission based on the literature and current knowledge. Moreover, we provide thorough description of the current understanding about ZIKV interaction with receptors, and a comparative examination of its similarities and differences with other viruses.

Zika virus knowledge and vaccine acceptance among undergraduate students in Guayaquil, Ecuador

Purpose

Zika virus (ZIKV) was declared a Public Health Emergency of International Concern (PHEIC) in 2016. Concerns surrounding the effects of ZIKV persist today and several vaccine candidates are currently in various stages of development worldwide. There is limited research on ZIKV vaccine acceptability worldwide, and little research specific to Latin American countries. This research aims to identify the general beliefs and acceptance of a potential ZIKV vaccine in the undergraduate population at Escuela Superior Politécnica del Litoral (ESPOL) in Guayaquil, Ecuador.

Methods

Between January and November 2019, 429 undergraduate students at ESPOL responded anonymously to a ZIKV vaccine survey. Frequencies, percentages, simple correspondence analysis, and bivariate inferential analyses were conducted using Kendall's tau-b test. Tests explored associations between likelihood of receiving a ZIKV vaccine and demographic, ZIKV information seeking, ZIKV psychosocial variables, and ZIKV information source variables.

Results

Among the eligible participants, 241 (56.2%) were willing to receive a ZIKV vaccine if one was made commercially available. Most students were male (61.5%), age 20-25 (63.3%), and of mixed (Mestizo) race (95.3%). Results provided insight into student's knowledge on ZIKV, revealed television as the most common information source, and found most students were willing to receive a ZIKV vaccine were one to become available. Bivariate results revealed most respondents reported feeling neutral or likely to receive a ZIKV vaccine regardless of their agreeability with ZIKV information seeking behavior and psychosocial variables.

Conclusions

This study provides insight into ZIKV knowledge among ESPOL university students and reveals most respondents obtained ZIKV related information from television. The most common reason for not wanting to receive a hypothetical ZIKV vaccine was vaccine hesitancy. Likelihood of receiving a ZIKV vaccine was associated with several information seeking behavior and psychosocial variables. Public health campaigns should focus on comprehensive ZIKV education efforts in this population.

The Zika virus: an opportunity to revisit reproductive health needs and disparities

First isolated in 1947, the Zika virus was initially connected only to limited or sporadic human infections. In late 2015, the temporal clustering of a Zika outbreak and microcephaly in newborn babies from northeastern Brazil, and the identification of a causal link between the two, led to the characterization of the congenital Zika syndrome. In the wake of the epidemic, several countries from Latin America advised women to postpone pregnancies for periods ranging from six months to two years. These recommendations initiated critical conversations about the challenges of implementing them in societies with limited access to contraception, widespread socioeconomic inequalities, and high rates of unplanned and adolescent pregnancies. The messaging targeted exclusively women, despite a high prevalence of imbalances in the relationship power, and addressed all women as a group, failing to recognize that the decision to postpone pregnancies will impact different women in different ways, depending on their age at the time. Finally, in several countries affected by the Zika epidemic, due to restrictive reproductive policies, legally terminating a pregnancy is no longer an option even at the earliest time when brain malformations as part of the congenital Zika syndrome can be detected by ultrasonography. The virus continued to circulate after 2016 in several countries. Climate change models predict an expansion of the geographical area where local Zika transmission may occur, indicating that the interface between the virus, teratogenesis, and reproductive rights is a topic of considerable interest for medicine, social sciences, and public health for years to come.

Scientometric Analysis of Public Health Emergencies: 1994-2020

The purpose of this paper is to summarize the research hotspots and frontiers in the field of public health emergencies (PHE) between 1994–2020 through the scientometric analysis method. In total, 2247 literature works retrieved from the Web of Science core database were analyzed by CiteSpace software, and the results were displayed in knowledge mapping. The overall characteristics analysis showed that the number of publications and authors in the field of PHE kept an upward trend during the past decades, and the United States was in the leading position, followed by China and England. Switzerland has the highest central value and plays an important intermediary role in promoting the integration and exchange of international PHE research achievements. The keyword co-occurrence analysis indicated that COVID-19 was the most high-frequency keyword in this field, and there had been no new keywords for a long time until the outbreak of COVID-19 in 2019. The burst detection analysis showed that the top five burst keywords in terms of burst intensity were zika virus, Ebola, United States, emergency preparedness and microcephaly. The results indicated that the research theme of PHE is closely related to the major infectious diseases in a specific period. It will continue to develop with more attention paid to public health. The conclusions can provide help and reference for the PHE potential researchers.

Contemporary Understanding of Ebola and Zika Virus in Pregnancy

Understanding the pathophysiology, management, and prevention of emerging infectious diseases among pregnant women is imperative to achieve a successful response from the medical community. Ebola and Zika viruses represent infections with profound public health implications. In particular, Ebola virus is associated with high case fatality and pregnancy and neonatal loss rates, while Zika virus has been associated with multiple congenital anomalies; these features present critical clinical dilemmas for management of pregnant and reproductive aged women. The objective of this article is to summarize key background information and best practices for management of Ebola and Zika virus in pregnancy.

The Role of Urban Morphology Design on Enhancing Physical Activity and Public Health

Along with environmental pollution, urban planning has been connected to public health. The research indicates that the quality of built environments plays an important role in reducing mental disorders and overall health. The structure and shape of the city are considered as one of the factors influencing happiness and health in urban communities and the type of the daily activities of citizens. The aim of this study was to promote physical activity in the main structure of the city via urban design in a way that the main form and morphology of the city can encourage citizens to move around and have physical activity within the city. Functional, physical, cultural-social, and perceptual-visual features are regarded as the most important and effective criteria in increasing physical activities in urban spaces, based on literature review. The environmental quality of urban spaces and their role in the physical activities of citizens in urban spaces were assessed by using the questionnaire tool and analytical network process (ANP) of structural equation modeling. Further, the space syntax method was utilized to evaluate the role of the spatial integration of urban spaces on improving physical activities. Based on the results, consideration of functional diversity, spatial flexibility and integration, security, and the aesthetic and visual quality of urban spaces plays an important role in improving the physical health of citizens in urban spaces. Further, more physical activities, including motivation for walking and the sense of public health and happiness, were observed in the streets having higher linkage and space syntax indexes with their surrounding texture.

University Students' Knowledge, Attitudes, and Sources of Information About Zika Virus

Colleges and universities are valuable partners for community health education outreach targeted to young adults. After the outbreak of Zika virus infection in the Americas was declared to be a Public Health Emergency of International Concern on February 1, 2016, postsecondary institutions played an important role in educating at-risk communities about health promotion and disease prevention strategies. In April 2016, we recruited 613 undergraduate students from a large public university to complete a survey about their Zika-related knowledge, attitudes, and information seeking behaviors. We standardized the results so that the participants' reports would be representative of the age, sex, major (course of study), and other characteristics of the university's student population. Most students knew that Zika virus is spread by mosquitoes (88.1%), but only about half knew that the virus could be transmitted through sexual intercourse (56.8%). Students perceived Zika to be a health risk for pregnant women in Zika-affected countries (83.0%), but did not personally feel at risk (12.1%). Many students (43.8%) reported not knowing where to get accurate information about Zika. Identifying gaps in scientific knowledge, misperceptions about personal susceptibility, and opportunities for behavioral risk reduction is an important foundation for designing community-based health interventions when future emerging infectious disease events occur.

Zika virus infection in Nicaraguan households

Zika virus (ZIKV) infection recently caused major epidemics in the Americas and is linked to congenital birth defects and Guillain-Barré Syndrome. A pilot study of ZIKV infection in Nicaraguan households was conducted from August 31 to October 21, 2016, in Managua, Nicaragua. We enrolled 33 laboratory-confirmed Zika index cases and their household members (109 contacts) and followed them on days 3–4, 6–7, 9–10, and 21, collecting serum/plasma, urine, and saliva specimens along with clinical, demographic, and socio-economic status information. Collected samples were processed by rRT-PCR to determine viral load (VL) and duration of detectable ZIKV RNA in human bodily fluids. At enrollment, 11 (10%) contacts were ZIKV rRT-PCR-positive and 23 (21%) were positive by IgM antibodies; 3 incident cases were detected during the study period. Twenty of 33 (61%) index households had contacts with ZIKV infection, with an average of 1.9 (range 1–6) positive contacts per household, and in 60% of these households, ≥50% of the members were positive for ZIKV infection. Analysis of clinical information allowed us to estimate the symptomatic to asymptomatic (S:A) ratio of 14:23 (1:1.6) among the contacts, finding 62% of the infections to be asymptomatic. The maximum number of days during which ZIKV RNA was detected was 7 days post-symptom onset in saliva and serum/plasma and 22 days in urine. Overall, VL levels in serum/plasma, saliva, and urine specimens were comparable, with means of 5.6, 5.3 and 4.5 log₁₀ copies/ml respectively, with serum attaining the highest VL peak at 8.1 log₁₀ copies/ml. Detecting ZIKV RNA in saliva over a similar time-period and level as in serum/plasma indicates that saliva could potentially serve as a more accessible diagnostic sample. Finding the majority of infections to be asymptomatic emphasizes the importance of silent ZIKV transmission and helps inform public health interventions in the region and globally.

Zika virus (ZIKV) infection has become a major concern due to its association with congenital birth defects and Guillain-Barré Syndrome. We enrolled 33 laboratory-confirmed Zika cases (index cases) and their household members (109 contacts) in Managua, Nicaragua, and followed them for three weeks, collecting serum/plasma, urine and saliva specimens along with clinical, demographic, and socio-economic status information. We found that 61% of the index households had contacts with ZIKV infection, with an average of 1.9 (range 1–6) positive contacts per household, and in 60% of these households, ≥50% of the members were ZIKV-positive. Analysis of clinical information allowed estimating the symptomatic to asymptomatic (S:A) ratio of 14:23 (1:1.6) among the contacts. Finding 62% of the infections to be asymptomatic emphasizes the importance of silent transmission. Evaluating the maximum number of days during which ZIKV RNA was detectable showed that ZIKV was found up to 7 days post-symptom onset in serum/plasma and saliva and 22 days post-symptom onset in urine. Finding ZIKV RNA in saliva over a similar time period and concentration as serum/plasma indicates that saliva could potentially serve as a more accessible diagnostic sample. Overall, these data increase our understanding of ZIKV transmission and help inform public health interventions in the region and globally.