Zika Virus Risk Research Articles

Surveillance of congenital Zika syndrome in England and Wales: methods and results of laboratory, obstetric and paediatric surveillance.

The spread of the Zika virus (ZIKV) in the Americas led to large outbreaks across the region and most of the Southern hemisphere. Of greatest concern were complications following acute infection during pregnancy. At the beginning of the outbreak, the risk to unborn babies and their clinical presentation was unclear. This report describes the methods and results of the UK surveillance response to assess the risk of ZIKV to children born to returning travellers. Established surveillance systems operating within the UK - the paediatric and obstetric surveillance units for rare diseases, and national laboratory monitoring - enabled rapid assessment of this emerging public health threat. A combined total of 11 women experiencing adverse pregnancy outcomes after possible ZIKV exposure were reported by the three surveillance systems; five miscarriages, two intrauterine deaths and four children with clinical presentations potentially associated with ZIKV infection. Sixteen women were diagnosed with ZIKV during pregnancy in the UK. Amongst the offspring of these women, there was unequivocal laboratory evidence of infection in only one child. In the UK, the number and risk of congenital ZIKV infection for travellers returning from ZIKV-affected countries is very small.

The Effects of Zika Virus Risk Coverage on Familiarity, Knowledge and Behavior in the U.S. – A Time Series Analysis Combining Content Analysis and a Nationally Representative Survey

ABSTRACTThis study assessed the effects of the February through September 2016 American news media’s coverage of Zika Virus (ZIKV) risk on the U.S. public’s familiarity, knowledge and behavior in the form of interpersonal discussions. A content analysis (N = 2,782 pieces) revealed that the Rio Olympic Games elicited a spike in coverage of Zika. We also found that newsworthy and easy- to- depict aspects of the disease, specifically its transmission by mosquitoes and its relation to microcephaly were covered more extensively than its sexual transmission and transmissibility from an infected person who is asymptomatic. Nevertheless, survey data over the same period of time (N = 37,180 respondents) revealed that the general amount of coverage, rather than the specifics about Zika transmission and its consequences, influenced the public’s familiarity, knowledge, and behavior.

Quantifying the risk of local Zika virus transmission in the contiguous US during the 2015\u20132016 ZIKV epidemic

BackgroundLocal mosquito-borne Zika virus (ZIKV) transmission has been reported in two counties in the contiguous United States (US), prompting the issuance of travel, prevention, and testing guidance across the contiguous US. Large uncertainty, however, surrounds the quantification of the actual risk of ZIKV introduction and autochthonous transmission across different areas of the US.MethodsWe present a framework for the projection of ZIKV autochthonous transmission in the contiguous US during the 2015–2016 epidemic using a data-driven stochastic and spatial epidemic model accounting for seasonal, environmental, and detailed population data. The model generates an ensemble of travel-related case counts and simulates their potential to have triggered local transmission at the individual level in the 2015–2016 ZIKV epidemic.ResultsWe estimate the risk of ZIKV introduction and local transmission at the county level and at the 0.025° × 0.025° cell level across the contiguous US. We provide a risk measure based on the probability of observing local transmission in a specific location during a ZIKV epidemic modeled after the epidemic observed during the years 2015–2016. The high spatial and temporal resolution of the model allows us to generate statistical estimates of the number of ZIKV introductions leading to local transmission in each location. We find that the risk was spatially heterogeneously distributed and concentrated in a few specific areas that account for less than 1% of the contiguous US population. Locations in Texas and Florida that have actually experienced local ZIKV transmission were among the places at highest risk according to our results. We also provide an analysis of the key determinants for local transmission and identify the key introduction routes and their contributions to ZIKV transmission in the contiguous US.ConclusionsThis framework provides quantitative risk estimates, fully captures the stochasticity of ZIKV introduction events, and is not biased by the under-ascertainment of cases due to asymptomatic cases. It provides general information on key risk determinants and data with potential uses in defining public health recommendations and guidance about ZIKV risk in the US.

Perceptions of Zika Virus Risk during 2016 Outbreak, Miami-Dade County, Florida, USA

We conducted a survey on Zika virus perceptions and behaviors during the 2016 outbreak in Miami-Dade County, Florida, USA. Among women, Zika knowledge was associated with having a bachelor’s degree. Among men, knowledge was associated with knowing someone at risk. Interventions during future outbreaks could be targeted by sex and education level.

Mapping the transmission risk of Zika virus using machine learning models

Zika virus, which has been linked to severe congenital abnormalities, is exacerbating global public health problems with its rapid transnational expansion fueled by increased global travel and trade. Suitability mapping of the transmission risk of Zika virus is essential for drafting public health plans and disease control strategies, which are especially important in areas where medical resources are relatively scarce. Predicting the risk of Zika virus outbreak has been studied in recent years, but the published literature rarely includes multiple model comparisons or predictive uncertainty analysis. Here, three relatively popular machine learning models including backward propagation neural network (BPNN), gradient boosting machine (GBM) and random forest (RF) were adopted to map the probability of Zika epidemic outbreak at the global level, pairing high-dimensional multidisciplinary covariate layers with comprehensive location data on recorded Zika virus infection in humans. The results show that the predicted high-risk areas for Zika transmission are concentrated in four regions: Southeastern North America, Eastern South America, Central Africa and Eastern Asia. To evaluate the performance of machine learning models, the 50 modeling processes were conducted based on a training dataset. The BPNN model obtained the highest predictive accuracy with a 10-fold cross-validation area under the curve (AUC) of 0.966 [95% confidence interval (CI) 0.965-0.967], followed by the GBM model (10-fold cross-validation AUC = 0.964[0.963-0.965]) and the RF model (10-fold cross-validation AUC = 0.963[0.962-0.964]). Based on training samples, compared with the BPNN-based model, we find that significant differences (p = 0.0258* and p = 0.0001***, respectively) are observed for prediction accuracies achieved by the GBM and RF models. Importantly, the prediction uncertainty introduced by the selection of absence data was quantified and could provide more accurate fundamental and scientific information for further study on disease transmission prediction and risk assessment.

Zika Virus Prevention: U.S. Travelers' Knowledge, Risk Perceptions, and Behavioral Intentions-A National Survey.

.Limited data exist about U.S. travelers’ knowledge, risk perceptions, and behaviors related to the Zika virus (ZIKV). Using an internet research panel, in March 2017, we surveyed 1,202 Americans in the continental United States and Puerto Rico who planned to travel to a ZIKV-affected country, state, or U.S. territory in 2017. We compared levels of knowledge and perceived risk of ZIKV, and intentions to practice ZIKV prevention behaviors across respondents from three regions: Puerto Rico, at-risk states, and other states. More than 80% of respondents correctly understood that a person could acquire ZIKV through a bite from an infected mosquito, and over 64% of respondents knew that a pregnant woman could pass the virus to her fetus. Less than half of the respondents from at-risk states and other states knew that ZIKV could be transmitted sexually, as compared with three-quarters of respondents from Puerto Rico. Compared with respondents from at-risk and other states, respondents from Puerto Rico were the most knowledgeable for almost all types of knowledge assessed. Knowledge about post-travel precautions was low across all three regions. Differences in perceived risk and intentions to practice specific prevention behaviors also varied among regions. Significant gaps exist in U.S. travelers’ knowledge about how to prevent ZIKV transmission both during and after travel. Input and collaboration from the travel industry, health care providers, and the media are needed to help educate travelers about how to prevent ZIKV infection and transmission.

United States Travelers' Concern about Zika Infection and Willingness to Receive a Hypothetical Zika Vaccine.

.The ongoing Zika pandemic has affected many countries that are common travel destinations. We assessed the willingness to receive a prophylactic Zika virus (ZIKV) vaccine, currently under development, among travelers to areas with reported autochthonous ZIKV transmission. We surveyed United States (U.S.) residents aged 18–44 years who had ever heard of ZIKV and planned to travel to Florida and/or Texas (N = 420) or a U.S. territory or foreign country (N = 415) in 2017, using a nationally representative internet panel. Travelers to Florida and/or Texas reported less concern about ZIKV infection than travelers to other destinations (27% versus 36%, P = 0.01). Female sex, Hispanic ethnicity, discussing ZIKV with medical professionals, ZIKV risk perception, and self-efficacy for ZIKV prevention predicted concern about ZIKV infection in both groups. Travelers to Florida and/or Texas (43%) and other destinations (44%) were equally willing to receive a ZIKV vaccine. Hispanic ethnicity, discussing ZIKV with medical professionals, and concern about ZIKV infection predicted vaccine willingness in both groups. Likelihood of using existing ZIKV prevention methods, confidence in the U.S. government to prevent ZIKV spread, self-efficacy for ZIKV prevention, and knowledge about ZIKV symptoms further predicted vaccine willingness in travelers to other destinations. In multivariable analyses, only concern about ZIKV infection was associated with vaccine willingness in both groups (prevalence ratio [95% confidence interval]: Florida and/or Texas: 1.34 [1.06, 1.69]; other: 1.82 [1.44, 2.29]). Targeted communications can educate travelers, particularly travelers who are pregnant or may become pregnant, about ZIKV risk to generate ZIKV vaccine demand.

Zika virus RNA polymerase chain reaction on the utility channel of a commercial nucleic acid testing system.

Several countries have implemented safety strategies to reduce the risk of Zika virus (ZIKV) transmission through blood transfusion. These strategies have included nucleic acid amplification testing (NAT) of blood donations. In this study, a new real-time polymerase chain reaction (PCR) assay including internal control for the detection of ZIKV on the cobas omni Utility Channel (UC) on the cobas 6800 system is presented. PCR conditions and primer/probe concentrations were optimized on the LightCycler 480 instrument. Optimized conditions were transferred to the cobas omni UC on the cobas 6800 system. Subsequently, the limit of detection (LOD) in plasma and urine, genotype inclusivity, specificity, cross-reactivity, and clinical sensitivity were determined. The 95% LOD of the ZIKV PCR assay on the cobas 6800 system was 23.0 IU/mL (95% confidence interval [CI], 16.5-37.5) in plasma and 24.5 IU/mL (95% CI, 13.4-92.9) in urine. The assay detected African and Asian lineages of ZIKV. The specificity was 100%. The clinical concordance between the newly developed ZIKV PCR assay and the investigational Roche cobas Zika NAT test was 83% (24/29). We developed a sensitive ZIKV PCR assay on the cobas omni UC on the cobas 6800 system. The assay can be used for large-scale screening of blood donations for ZIKV or for testing of blood donors returning from areas with ZIKV to avoid temporal deferral. This study also demonstrates that the cobas omni UC on the cobas 6800 system can be used for in-house-developed PCR assays.

Quantifying Zika: Advancing the Epidemiology of Zika With Quantitative Models.

When Zika virus (ZIKV) emerged in the Americas, little was known about its biology, pathogenesis, and transmission potential, and the scope of the epidemic was largely hidden, owing to generally mild infections and no established surveillance systems. Surges in congenital defects and Guillain-Barré syndrome alerted the world to the danger of ZIKV. In the context of limited data, quantitative models were critical in reducing uncertainties and guiding the global ZIKV response. Here, we review some of the models used to assess the risk of ZIKV-associated severe outcomes, the potential speed and size of ZIKV epidemics, and the geographic distribution of ZIKV risk. These models provide important insights and highlight significant unresolved questions related to ZIKV and other emerging pathogens.

A survey-based study of Zika virus communication preferences among pregnant women in Georgia, United States

BackgroundBecause of the particularly severe perinatal outcomes associated with antenatal Zika virus infection, it is important for prenatal care providers to communicate Zika virus risks and strategies for prevention to their patients. Although face-to-face communication is ideal, clinic visits may not allow for in-depth discussion of all concerns. While previous studies have shown prenatal providers to be pregnant women’s most trusted sources of health information, there is little knowledge on what secondary communication modalities pregnant women prefer for receiving information from their providers about an evolving public health emergency.MethodsA cross-sectional, descriptive anonymous 27-item survey was distributed to pregnant women at four clinics around Atlanta, Georgia from May 5th to June 20th, 2016. The survey assessed women’s interest in and communication preferences about prenatal topics, including Zika virus. Descriptive statistics were calculated and chi-square tests were used to evaluate associations between the primary outcomes and patient characteristics.ResultsFour-hundred and eight women completed the survey. The most popular resource for obtaining Zika virus information was the Centers for Disease Control and Prevention (CDC) website (73.0%). While their prenatal provider’s own website for Zika information ranked 5th among sources currently accessed for Zika information, it ranked third behind educational brochures and emails for ways in which women wanted to receive information. The characteristics of Zika virus information deemed most important were: evidence-based (87.5%), endorsed by the CDC (74.1%), and endorsed by their own provider (67.9%).ConclusionIn any public health emergency affecting pregnant women, women are going to seek advice from their obstetric providers. Because providers may lack sufficient time to discuss concerns with every patient, they may consider providing patient education in other ways. For the women included in this study, educational brochures, emails and providers’ own practice websites were preferred. Providers should consider taking greater advantage of these modalities to supplement in-person exchanges, particularly during a public health emergency.

Perceptions of Zika virus risk in Germany in 2016.

Risks associated with Zika virus (ZIKV) transmission in the Americas have been discussed widely in the media as several European athletes declined to participate in the 2016 Summer Olympic Games. Since risk perceptions of individuals in unaffected areas are unknown, we assessed the risk perceptions of ZIKV and related behaviour in Lower Saxony, Germany, with a specific focus on pregnant women and their partners. In May 2016, we surveyed 1,037 participants aged 15-69 years of an online panel (addressing hygiene and preventive behaviour regarding infections) in Lower Saxony with respect to their risk perceptions related to ZIKV. We additionally included 26 expectant parents who were recruited at antenatal preparation courses in Braunschweig and Hannover between May and July 2016. Six hundred fifty-five (69.1%) of the panel participants had ever heard about ZIKV. About 8% of the study participants reported to be concerned about ZIKV. Pregnant women had the highest odds of reporting concern about ZIKV (OR: 6.24; 95% CI: 2.94-13.26, reference: non-pregnant women). The vast majority of participants (79%) would travel to the Olympics if they won a free trip; this proportion was lower in currently pregnant women (46%). Risk perceptions towards ZIKV were considerably lower than those towards Ebola during the 2014 epidemic. This study showed that fear of contracting ZIKV is not a major deterrent for travelling to high-risk areas. Pregnant women are appropriately concerned about the risk of ZIKV. Studies modelling the further spread of ZIKV need to account for these results.

Inactivation of Zika virus in platelet components using amotosalen and ultraviolet A illumination.

Concerned over the risk of Zika virus (ZIKV) transfusion transmission, public health agencies recommended the implementation of mitigation strategies for its prevention. Those strategies included the use of pathogen inactivation for the treatment of plasma and platelets. The efficacy of amotosalen/ultraviolet A to inactivate ZIKV in plasma had been previously demonstrated, and the efficacy of inactivation in platelets with the same technology was assumed. These studies quantify ZIKV inactivation in platelet components using amotosalen/ultraviolet A. Platelet components were spiked with ZIKV, and ZIKV infectious titers and RNA loads were measured by cell culture-based assays and real-time polymerase chain reaction in spiked platelet components before and after photochemical treatment using amotosalen/ultraviolet A. The mean ZIKV infectivity titers and RNA loads in platelet components before inactivation were either 4.9 log10 plaque forming units per milliliter, or 4.4 log10 50% tissue culture infective dose per milliliter and 7.5 log10 genome equivalents per milliliter, respectively. No infectivity was detected immediately after amotosalen/ultraviolet A treatment. No replicative virus remained after treatment, as demonstrated by multiple passages on Vero cell cultures; and ZIKV RNA was not detected from the first passage after inactivation. Additional experiments in this study demonstrated efficient inactivation to the limit of detection in platelets manufactured in 65% platelet additive solution, 35% plasma, or 100% plasma. As previously demonstrated for plasma, robust levels of ZIKV inactivation were achieved in platelet components. With inactivation of higher levels of ZIKV than those reported in asymptomatic, RNA-reactive blood donors, the pathogen-inactivation system using amotosalen/ultraviolet A offers the potential to mitigate the risk of ZIKV transmission by plasma and platelet transfusion.

On the origin and timing of Zika virus introduction in Brazil.

The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June-July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12-22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.

Emerging infectious disease agents and blood safety in Australia: spotlight on Zika virus.

Emerging infectious diseases (EIDs) are infectious diseases whose incidence has increased in humans in the past 20 years or could increase in the near future. EID agents may represent a threat to blood safety if they infect humans, cause a clinically significant illness, include an asymptomatic blood phase in the course of infection, and are transmissible by transfusion. EID agents are typically not well characterised, but there is a consensus that we can expect ongoing outbreaks. Strategies to manage the risk to blood safety from EIDs include ongoing surveillance, regular risk assessments, modelling transfusion transmission risk, and deferral of donors with a recent travel history to outbreak areas. The 2015-16 Zika virus (ZIKV) outbreak in the Americas is the largest reported ZIKV outbreak to date, and it highlights the unpredictable nature of EID outbreaks and how quickly they can become a major public health problem. This ZIKV outbreak has provided evidence of a causal link between the virus and microcephaly in newborns. In assessing the potential risk of ZIKV to blood safety in Australia, it should be noted that a relatively small number of imported ZIKV infections have been reported in Australia, there have been no reported cases of local ZIKV transmission, and the geographical distribution of the potential ZIKV mosquito vector in Australia (Aedes aegypti) is limited to northern Queensland. Moreover, reported transfusion-transmitted ZIKV cases worldwide are rare. At present, ZIKV represents a low risk to blood safety in Australia.

Cost projections for implementation of safety interventions to prevent transfusion-transmitted Zika virus infection in the United States.

In August 2016, the Food and Drug Administration advised US blood centers to screen all whole blood and apheresis donations for Zika virus (ZIKV) with an individual-donor nucleic acid test (ID-NAT) or to use approved pathogen reduction technology (PRT). The cost of implementing this guidance nationally has not been assessed. Scenarios were constructed to characterize approaches to ZIKV screening, including universal ID-NAT, risk-based seasonal allowance of minipool (MP) NAT by state, and universal MP-NAT. Data from the 2015 National Blood Collection and Utilization Survey (NBCUS) were used to characterize the number of donations nationally and by state. For each scenario, the estimated cost per donor ($3-$9 for MP-NAT, $7-$13 for ID-NAT) was multiplied by the estimated number of relevant donations from the NBCUS. Cost of PRT was calculated by multiplying the cost per unit ($50-$125) by the number of units approved for PRT. Prediction intervals for costs were generated using Monte Carlo simulation methods. Screening all donations in the 50 states and DC for ZIKV by ID-NAT would cost $137 million (95% confidence interval [CI], $109-$167) annually. Allowing seasonal MP-NAT in states with lower ZIKV risk could reduce NAT screening costs by 18% to 25%. Application of PRT to all platelet (PLT) and plasma units would cost $213 million (95% CI, $156-$304). Universal ID-NAT screening for ZIKV will cost US blood centers more than $100 million annually. The high cost of PRT for apheresis PLTs and plasma could be mitigated if, once validated, testing for transfusion transmissible pathogens could be eliminated.

Emerging Infectious Diseases and Blood Safety: Modeling the Transfusion-Transmission Risk.

While the transfusion-transmission (TT) risk associated with the major transfusion-relevant viruses such as HIV is now very low, during the last 20 years there has been a growing awareness of the threat to blood safety from emerging infectious diseases, a number of which are known to be, or are potentially, transfusion transmissible. Two published models for estimating the transfusion-transmission risk from EIDs, referred to as the Biggerstaff-Petersen model and the European Upfront Risk Assessment Tool (EUFRAT), respectively, have been applied to several EIDs in outbreak situations. We describe and compare the methodological principles of both models, highlighting their similarities and differences. We also discuss the appropriateness of comparing results from the two models. Quantitating the TT risk of EIDs can inform decisions about risk mitigation strategies and their cost-effectiveness. Finally, we present a qualitative risk assessment for Zika virus (ZIKV), an EID agent that has caused several outbreaks since 2007. In the latest and largest ever outbreak, several probable cases of transfusion-transmission ZIKV have been reported, indicating that it is transfusion-transmissible and therefore a risk to blood safety. We discuss why quantitative modeling the TT risk of ZIKV is currently problematic.

Assessing real-time Zika risk in the United States

BackgroundConfirmed local transmission of Zika Virus (ZIKV) in Texas and Florida have heightened the need for early and accurate indicators of self-sustaining transmission in high risk areas across the southern United States. Given ZIKV’s low reporting rates and the geographic variability in suitable conditions, a cluster of reported cases may reflect diverse scenarios, ranging from independent introductions to a self-sustaining local epidemic.MethodsWe present a quantitative framework for real-time ZIKV risk assessment that captures uncertainty in case reporting, importations, and vector-human transmission dynamics.ResultsWe assessed county-level risk throughout Texas, as of summer 2016, and found that importation risk was concentrated in large metropolitan regions, while sustained ZIKV transmission risk is concentrated in the southeastern counties including the Houston metropolitan region and the Texas-Mexico border (where the sole autochthonous cases have occurred in 2016). We found that counties most likely to detect cases are not necessarily the most likely to experience epidemics, and used our framework to identify triggers to signal the start of an epidemic based on a policymakers propensity for risk.ConclusionsThis framework can inform the strategic timing and spatial allocation of public health resources to combat ZIKV throughout the US, and highlights the need to develop methods to obtain reliable estimates of key epidemiological parameters.

Spatial quantification of the world population potentially exposed to Zika virus.

Zika virus is an emerging Flaviviridae virus, which has spread rapidly in the last few years. It has raised concern because it has been associated with fetus microcephaly when pregnant women are infected. The main vector is the mosquito Aedes aegypti , distributed in tropical areas. Niche modelling techniques were used to estimate the potential distribution area of A. aegypti. This was overlapped with human population density, determining areas of potential transmission risk worldwide. Afterwards, we quantified the population at risk according to risk level. The vector transmission risk is distributed mainly in Asia and Oceania on the shores of the Indian Ocean. In America, the risk concentrates in the Atlantic coast of South America and in the Caribbean Sea shores in Central and North America. In Africa, the major risk is concentrated in the Pacific and Atlantic coasts of Central and South Africa. The world population under high and very high risk levels includes 2.261 billion people. These results illustrate Zika virus risk at the global level and provide maps to target the prevention and control measures especially in areas with higher risk, in countries with less sanitation and poorer resources. Many countries without previous vector reports could become active transmission zones in the future, so vector surveillance should be implemented or reinforced in these areas.

Application of the analytic hierarchy approach to the risk assessment of Zika virus disease transmission in Guangdong Province, China

BackgroundAn international spread of Zika virus (ZIKV) infection has attracted global attention in 2015. The infection also affected Guangdong province, which is located in southern China. Multiple factors, including frequent communication with South America and Southeast Asia, suitable climate (sub-tropical) for the habitat of Aedes species, may increase the risk of ZIKV disease transmission in this region.MethodsAn analytic hierarchy process (AHP) method was used to develop a semi-quantitative ZIKV risk assessment model. After selecting indicators, we invited experts in related professions to identify the index weight and based on that a hierarchical structure was generated. Then a series of pairwise comparisons were used to determine the relative importance of the criteria. Finally, the optimal model was established to estimate the spatial and seasonal transmission risk of ZIKV.ResultsA total of 15 factors that potentially influenced the risk of ZIKV transmission were identified. The factor that received the largest weight was epidemic of ZIKV in Guangdong province (combined weight [CW] =0.37), followed by the mosquito density (CW = 0.18) and the epidemic of DENV in Guangdong province (CW = 0.14). The distribution of 123 districts/counties’ RIs of ZIKV in Guangdong through different seasons were presented, respectively.ConclusionsHigher risk was observed within Pearl River Delta including Guangzhou, Shenzhen and Jiangmen, and the risk is greater in summer and autumn compared to spring and winter.

Strengthening reproductive and sexual health services to minimize the risk of Zika virus associated complications in newborn

Strengthening reproductive and sexual health services to minimize the risk of Zika virus associated complications in newborn