Zika Virus Transmission Research Articles

The Factors Associated with Prevention and Control Practices against Zika Virus Infection among Pregnant Women in Malaysia, a Dengue-Endemic Country.

The aim of this study was to analyze the prevention and control practices against Zika virus (ZIKV) infection among pregnant women in Malaysia. A cross-sectional study was conducted among pregnant women who received antenatal care. Only 7.8% reported that they abstained from sex or used barrier methods during sexual intercourse to prevent ZIKV transmission. The odds of abstaining from sex or using barrier methods were significantly higher among the Chinese ethnic group than the Malay ethnic group (odds ratio [OR] = 4.569; 95% confidence interval [CI]: 2.696-7.743). A total ZIKV knowledge score of 12-24 was also significantly associated with higher odds of abstaining from sex or using barrier methods than a score of 0-11 (OR = 2.819; 95% CI: 1.682-4.725). In total, 38.6% of women had a higher mean total score for all the current mosquito control practices than they did before hearing of ZIKV. Participants living in bungalows or village houses (OR = 2.006; 95% CI: 1.023-3.936) and low-rise houses (OR = 1.566; 95% CI: 1.109-2.212) were more likely to have a higher mean total score of current mosquito control practices than the practices before hearing of ZIKV compared to those in high-rise houses. The lack of ZIKV knowledge and control practices provides insight for the pre-emptive and prompt development of health education systems for pregnant women during antenatal care visits.

Status of Vector Control Capabilities and Capacities in Florida and Texas, and its Potential Public Health Consequences.

It has been reported that roughly 80% of vector control organizations throughout the southern USA lack critical capabilities to properly address potential vector populations and vector-borne diseases within their jurisdictions. This study further investigated current vector control capabilities and capacity within the states of Florida and Texas. It was reported that only 26% of jurisdictions in Florida and 14% in Texas reported that they were "fully capable." Both states are among the top 4 states relative to the number of human cases of mosquito-borne diseases, and both states have had local transmission of Zika virus. Respondents from Florida indicated that 88% of jurisdictions have vector control capabilities to some degree, with 65% of those reporting they had sufficient capabilities. Respondents from Texas indicated that 89% of jurisdictions have vector control capabilities to some degree, with 67% of those reporting they had sufficient capabilities. As the prioritization of resource commitment for vector control capabilities varies throughout the USA, it is imperative that each state evaluates their specific needs and current capabilities and capacity to best ensure the public health needs of their constituents.

Caputo fractional order derivative model of Zika virus transmission dynamics

The Zika Virus (ZIKV) is a highly contagious disease, and several outbreaks have occurred since it emerged. It is transmitted from one to another human via a mosquito Aedes aegypti. There is no vaccine or established medicine available for ZIKV to date. There is an urgent need to enhance an understanding of the progression mechanism of the disease when drugs or vaccines are not available. Mathematical modeling is a tool that might be helpful to understand the progression dynamics of ZIKV which can enable us to make control strategies for invading the progression dynamics of disease. SEIR-SEI is a famous compartmental deterministic modeling based on integer-order derivative calculus. Nowadays, conversion from integer to fractional order-based derivative modeling is in trend, and it is a very effective and high degree of accuracy. In this paper, we proposed a Caputo fractional-order based susceptible-exposed-infected-recovered (SEIR) structure for hosts and a susceptible-exposed-infected (SEI) structure for mosquitoes for transmission dynamics of ZIKV. For this purpose, we modified the classical compartmental model used in the study of progression dynamics of the Zika fever outbreak in El-Salvador during 2015-16. The modified model involves nonlinear differential equations of fractional (non-integer) order which has an advantage over the classical model due to its memory effect property. Our study includes eight regions across the globe where the Zika outbreak has occurred during the year 2013-2016 including six major archipelagos of French Polynesia, i.e., Tahiti, Sous-le-vent, Moorea, Tuamotu, Marquises, and Australes. The other two regions included Costa Rica and Colombia. The outbreak in selected regions was studied first using a classical model and then compared by a fractional-order model. The data of outbreaks are best fitted with the fractional-order model which enables us to estimate the best parameters values for the outbreaks. Using this modeling, the epidemic threshold parameter $R_0$ was computed which is more accurate than the classical one. Hence, the fractional-order model for ZIKV transmission dynamics is much better prediction, analysis, and disease parameters estimation than the classical model. This modeling enhances the knowledge in the field of fractional order and understanding the ZIKV transmission accurately.

Interferon Lambda Signals in Maternal Tissues to Exert Protective and Pathogenic Effects in a Gestational Stage-Dependent Manner.

ABSTRACTInterferon lambda (IFN-λ) (type III IFN) is constitutively secreted from human placental cells in culture and reduces Zika virus (ZIKV) transplacental transmission in mice. However, the roles of IFN-λ during healthy pregnancy and in restricting congenital infection remain unclear. Here, we used mice lacking the IFN-λ receptor (Ifnlr1−/−) to generate pregnancies lacking either maternal or fetal IFN-λ responsiveness and found that the antiviral effect of IFN-λ resulted from signaling exclusively in maternal tissues. This protective effect depended on gestational stage, as infection earlier in pregnancy (E7 rather than E9) resulted in enhanced transplacental transmission of ZIKV. In Ifnar1−/− dams, which sustain robust ZIKV infection, maternal IFN-λ signaling caused fetal resorption and intrauterine growth restriction. Pregnancy pathology elicited by poly(I·C) treatment also was mediated by maternal IFN-λ signaling, specifically in maternal leukocytes, and also occurred in a gestational stage-dependent manner. These findings identify an unexpected effect of IFN-λ signaling, specifically in maternal (rather than placental or fetal) tissues, which is distinct from the pathogenic effects of IFN-αβ (type I IFN) during pregnancy. These results highlight the complexity of immune signaling at the maternal-fetal interface, where disparate outcomes can result from signaling at different gestational stages.

Fuzzy Epidemic Model for the Transmission of Zika Virus

Zika fever is a mosquito-borne infectious disease. The virus gets rid of the body eventually and it is not permanent. In February 2016, the Zika virus was declared a public health emergency by the World Health Organization. In this paper, we have constructed an SEIR-SEI model along with fuzzy parameters. The population is considered heterogeneous. The transmission rate and the recovery rate play a crucial role in the transmission of the Zika virus, which is uncertain and thus they are taken as fuzzy numbers and their corresponding membership function is considered as fuzzy parameters. Further, we study the equilibrium point, classical reproduction number, and the fuzzy basic reproduction number. The fuzzy basic reproduction number with the different virus loads is shown in this paper. The main objective of this paper is, by computing the reproduction value, we control the spread of the Zika virus in the future.

Early infection of Zika virus in the male reproductive system of AG129 mice: molecular and immunohistochemical evaluation.

Sexual transmission of Zika virus (ZIKV), an important arbovirus, and the virus persistence in semen raise several questions about how and where it circulates in the male reproductive system (MRS). Several studies reported detection of the virus in testes, epididymis, and prostate at 5days post-infection (dpi) or more in animal models. In the present study, we investigated the interactions of ZIKV with mouse MRS using the AG129 strain, a ZIKV permissive immunodeficient mouse strain, at two dpi. Viral RNA was detected in blood, testes, epididymis, and prostatic complexes (prostate and seminal vesicles). Immunohistochemical (IHC) analyses, based on the envelope protein, showed an early infection in organs of MRS since ZIKV positive antigens were detected in cells within or surrounding blood vessels, Sertoli, and germ cells in testes and epithelial cells in epididymis and prostate. Positive antigens for NS5 protein, the virus RNA-dependent RNA polymerase, were also detected by IHC in these organs and circulating leukocytes, suggesting that the virus replicates in these sites as early as 2days post-infection. Analysis of the early stages of ZIKV infection in MRS may improve the current knowledge about this issue and contribute to the development of therapies directed to the infection at this site.

Excretion of Cell-Free and Cell-Associated Zika Virus into Breast Milk of Infected Dams and Identification of Antiviral Factors.

Zika virus (ZIKV) is a mosquito-borne RNA virus belonging to the Flavivirus genus of the Flaviviridae family. During the 60 years following its discovery in 1947, ZIKV caused little concern for public health as the associated infection was reported as mostly asymptomatic or inducing mild symptoms. However, since 2013, severe neurological symptoms have been associated with ZIKV infection, compelling the World Health Organization to declare a Public Health Emergency of International Concern. Among those symptoms, neurological birth defects may affect children born to mothers infected during pregnancy. Additionally, during the past 8 years, ZIKV transmission through breastfeeding has repeatedly been suggested in epidemiological studies and demonstrated on a mouse model by our team. To better understand the biological factors controlling ZIKV transmission through breastfeeding, we investigated the nature of the viral entities excreted in the breast milk of infected dams and evaluated viral transmission to breastfed pups. We show that both cell-free and cell-associated virus is excreted into breast milk and that ZIKV is efficiently transmitted to the breastfed pups. Additionally, we studied murine breast milk cell types, and identified a majority of mammary luminal cells. Finally, we investigated the effect on ZIKV infectivity of several breast milk components that are antiviral against different viruses such as lactoferrin (LF) and lactalbumin (LA), or free fatty acids (FFA). We showed no effect of LF and LA, whereas FFA inactivated the virus. These results bring new insight concerning the mechanisms of ZIKV transmission during breastfeeding and identify biological factors modulating it. These elements should be considered in risk assessment of ZIKV mother-to-child transmission.

Transplacental Zika virus transmission in ex vivo perfused human placentas.

A Zika virus (ZIKV) infection during pregnancy can result in severe birth defects such as microcephaly. To date, it is incompletely understood how ZIKV can cross the human placenta. Furthermore, results from studies in pregnant mice and non-human primates are conflicting regarding the role of cross-reactive dengue virus (DENV) antibodies on transplacental ZIKV transmission. Elucidating how ZIKV can cross the placenta and which risk factors contribute to this is important for risk assessment and for potential intervention strategies for transplacental ZIKV transmission. In this study we use an ex vivo human placental perfusion model to study transplacental ZIKV transmission and the effect that cross-reactive DENV antibodies have on this transmission. By using this model, we demonstrate that DENV antibodies significantly increase ZIKV uptake in perfused human placentas and that this increased uptake is neonatal Fc-receptor-dependent. Furthermore, we show that cross-reactive DENV antibodies enhance ZIKV infection in term human placental explants and in primary fetal macrophages but not in primary trophoblasts. Our data supports the hypothesis that presence of cross-reactive DENV antibodies could be an important risk factor for transplacental ZIKV transmission. Furthermore, we demonstrate that the ex vivo placental perfusion model is a relevant and animal friendly model to study transplacental pathogen transmission.

Backward bifurcation and optimal control in a co-infection model for SARS-CoV-2 and ZIKV

In co-infection models for two diseases, it is mostly claimed that, the dynamical behavior of the sub-models usually predict or drive the behavior of the complete models. However, under a certain assumption such as, allowing incident co-infection with both diseases, we have a different observation. In this paper, a new mathematical model for SARS-CoV-2 and Zika co-dynamics is presented which incorporates incident co-infection by susceptible individuals. It is worth mentioning that the assumption is missing in many existing co-infection models. We shall discuss the impact of this assumption on the dynamics of a co-infection model. The model also captures sexual transmission of Zika virus. The positivity and boundedness of solution of the proposed model are studied, in addition to the local asymptotic stability analysis. The model is shown to exhibit backward bifurcation caused by the disease-induced death rates and parameters associated with susceptibility to a second infection by those singly infected. Using Lyapunov functions, the disease free and endemic equilibria are shown to be globally asymptotically stable for R01, respectively. To manage the co-circulation of both infections effectively, under an endemic setting, time dependent controls in the form of SARS-CoV-2, Zika and co-infection prevention strategies are incorporated into the model. The simulations show that SARS-CoV-2 prevention could greatly reduce the burden of co-infections with Zika. Furthermore, it is also shown that prevention controls for Zika can significantly decrease the burden of co-infections with SARS-CoV-2.

Zika virus vertical transmission in interferon receptor1-antagonized Rag1\u2212/\u2212 mice results in postnatal brain abnormalities and clinical disease

The mechanisms by which vertically transmitted Zika virus (ZIKV) causes postnatal brain development abnormalities and congenital disease remain poorly understood. Here, we optimized the established anti-IFNAR1 treated, Rag1−/− (AIR) mouse model of ZIKV infection to examine the consequence of vertical transmission on neonate survival and postnatal brain development. We found that modulating the infectious dose and the frequency of anti-IFNAR1 treatment of pregnant mice (termed AIRlow mice) prolonged neonatal survival allowing for pathogenesis studies of brain tissues at critical postnatal time points. Postnatal AIRlow mice all had chronic ZIKV infection in the brain that was associated with decreased cortical thickness and cerebellar volume, increased gliosis, and higher levels of cell death in many brain areas including cortex, hippocampus and cerebellum when compared to controls. Interestingly, despite active infection and brain abnormalities, the neurodevelopmental program remained active in AIRlow mice as indicated by elevated mRNA expression of critical neurodevelopmental genes in the brain and enlargement of neural-progenitor rich regions of the cerebellum at a developmental time point analogous to birth in humans. Nevertheless, around the developmental time point when the brain is fully populated by neurons, AIRlow mice developed neurologic disease associated with persistent ZIKV infection in the brain, gliosis, and increased cell death. Together, these data show that vertically transmitted ZIKV infection in the brain of postnatal AIRlow mice strongly influences brain development resulting in structural abnormalities and cell death in multiple regions of the brain.

Fertility decision-making during the Zika virus epidemic in Brazil: Where is the decision?

BackgroundIn 2016, a Public Health Emergency of International Concern (PHEIC) was declared in response to the rise of microcephaly cases among newborns in Northeastern Brazil. A common reactionary measure by public health authorities was to recommend women postpone pregnancy to avoid the possible perinatal transmission of Zika virus (ZIKV). MethodsThe purpose of this study was to assess how women in Fortaleza, Brazil conceptualize pregnancy; experience facilitators and barriers to pregnancy avoidance; perceive the authorities’ recommendation to postpone pregnancy due to the ZIKV outbreak; and recall their experiences during the ZIKV epidemic. Qualitative methods, specifically a Rapid Anthropological Assessment (RAA), were utilized in this study. Data collection included semi-structured interviews, triangulated with observations and informal interviews with community members. ResultsThe sample included 35 women (18–39 years old) who exclusively utilized the national public health care system. Findings indicated that all participants perceived the ZIKV pregnancy-postponement recommendation to be counter-cultural to Brazilian social norms. Overall women’s self-perceived agency to prevent pregnancy was low due to social expectations and lack of trust for contraceptives. ZIKV prevention was not seen as a reason to utilize contraceptives. Interestingly, only women who self-perceived as more affluent were willing to attempt pregnancy prevention for educational, occupational, or financial opportunity. ConclusionPregnancy postponement as a response to a ZIKV epidemic ignores gaps in reproductive agency and defies social norms, making it unrealistic and counter-cultural. Future ZIKV health recommendations must be culturally aligned with the population, and address barriers and motivators for family planning.

Vertical Zika Virus Transmission at the Maternal-Fetal Interface

Zika virus (ZIKV) is spread by mosquito bites or via sexual or vertical transmission. ZIKV-infected adults are generally asymptomatic, but can display mild symptoms including fever, joint pain, rash and conjunctivitis. However, during pregnancy, vertical ZIKV transmission can cause placental dysfunction and elicit severe fetal defects, including microcephaly, retinopathy, fetal growth restriction and/or stillbirth. Since no FDA-approved vaccine or anti-viral agents are currently available, ZIKV infection poses a global maternal-fetal health challenge. The maternal-fetal interface consists of maternal decidual and immune cells as well as fetal-derived trophoblasts. Compared to other cell types at the maternal-fetal interface, syncytiotrophoblasts, which form the outer layer of floating villi, are less-permissive to ZIKV, thereby preventing ZIKV transmission to the underlying cytotrophoblasts and/or other cells such as Hofbauer cells or fetal endothelium in the villi. However, anchoring villi are tightly attached to the decidua and their cytotrophoblastic cell columns are ZIKV-permissive, suggesting this location as the most likely site of ZIKV vertical transmission. Thus, at the maternal-fetal interface, maternal decidual cells likely serve as a reservoir of ZIKV persistence since they: 1) overexpress viral entry molecules compared to trophoblasts; 2) are highly permissive to ZIKV infection in a gestational age-dependent manner (more easily infected earlier in gestation); 3) augment ZIKV infection of weakly permissive primary cytotrophoblast cultures; and 4) display local maternal-immune tolerance, which prolongs ZIKV survival to facilitate fetal transmission. This review focuses on molecular mechanisms underlying ZIKV infection of cells at the human maternal-fetal interface, thus highlighting how decidual cells enhance propagation of ZIKV in extravillous cytotrophoblasts and why development of agents that eliminate ZIKV persistence in reproductive tissues before pregnancy is crucial to prevent perinatal ZIKV transmission.

Traveling wave solutions for Zika transmission model with nonlocal diffusion

The problem of traveling wave solutions (TWS) for a nonlocal diffusive Zika transmission model with bilinear incidence was studied. More specifically, the system admits a nontrivial TWS if the threshold ℜ > 1 and c>c⁎, where c⁎ is the critical wave speed; the system admits no nontrivial TWS for ℜ > 1 and 0<c<c⁎ or ℜ ≤ 1. The proofs are based on sub- and super-solution methods, Schauder's fixed point theorem and Laplace transformation. We also explain the influence of model parameters on the transmission of Zika virus. Compared with the previous studies on nonlocal diffusive epidemic models, a major difficulty is the boundedness of TWS arising from the bilinear incidence. The main result helps us to provide some new perspectives for the TWS of the nonlocal diffusion epidemic model with multiple infectious compartments.

Aedes aegypti Shows Increased Susceptibility to Zika Virus via Both In Vitro and In Vivo Models of Type II Diabetes.

Chronic conditions like type II diabetes (T2DM) have long been known to exacerbate many infectious diseases. For many arboviruses, including Zika virus (ZIKV), severe outcomes, morbidity and mortality usually only occur in patients with such pre-existing conditions. However, the effects of T2DM and other pre-existing conditions on human blood (e.g., hypo/hyperinsulinemia, hyperglycemia and hyperlipidemia) that may impact infectivity of arboviruses for vectors is largely unexplored. We investigated whether the susceptibility of Aedes aegypti mosquitoes was affected when the mosquitoes fed on “diabetic” bloodmeals, such as bloodmeals composed of artificially glycosylated erythrocytes or those from viremic, diabetic mice (LEPRDB/DB). Increasing glycosylation of erythrocytes from hemoglobin A1c (HgbA1c) values of 5.5–5.9 to 6.2 increased the infection rate of a Galveston, Texas strain of Ae. aegypti to ZIKV strain PRVABC59 at a bloodmeal titer of 4.14 log10 FFU/mL from 0.0 to 40.9 and 42.9%, respectively. ZIKV was present in the blood of viremic LEPRDB/DB mice at similar levels as isogenic control C57BL/6J mice (3.3 log10 FFU/mL and 3.6 log10 FFU/mL, respectively. When mice sustained a higher ZIKV viremia of 4.6 log10 FFU/mL, LEPRDB/DB mice infected 36.3% of mosquitoes while control C57BL/6J mice with a viremia of 4.2 log10 FFU/mL infected only 4.1%. Additionally, when highly susceptible Ae. aegypti Rockefeller mosquitoes fed on homozygous LEPRDB/DB, heterozygous LEPRWT/DB, and control C57BL/6J mice with viremias of ≈ 4 log10 FFU/mL, 54%, 15%, and 33% were infected, respectively. In total, these data suggest that the prevalence of T2DM in a population may have a significant impact on ZIKV transmission and indicates the need for further investigation of the impacts of pre-existing metabolic conditions on arbovirus transmission.

A Retrospective Overview of Zika Virus Evolution in the Midwest of Brazil.

ABSTRACTSince the introduction of the Zika virus (ZIKV) into Brazil in 2015, its transmission dynamics have been intensively studied in many parts of the country, although much is still unknown about its circulation in the midwestern states. Here, using nanopore technology, we obtained 23 novel partial and near-complete ZIKV genomes from the state of Goiás, located in the Midwest of Brazil. Genomic, phylogenetic, and epidemiological approaches were used to retrospectively explore the spatiotemporal evolution of the ZIKV-Asian genotype in this region. As a likely consequence of a gradual accumulation of herd immunity, epidemiological data revealed a decline in the number of reported cases over 2018 to 2021. Phylogenetic reconstructions revealed that multiple independent introductions of the Asian lineage have occurred in Goiás over time and revealed a complex transmission dynamic between epidemic seasons. Together, our results highlight the utility of genomic, epidemiological, and evolutionary methods to understand mosquito-borne epidemics.IMPORTANCE Despite the considerable morbidity and mortality of arboviral infections in Brazil, such as Zika, chikungunya, dengue fever, and yellow fever, our understanding of these outbreaks is hampered by the limited availability of genomic data to track and control the epidemic. In this study, we provide a retrospective reconstruction of the Zika virus transmission dynamics in the state of Goiás by analyzing genomic data from areas in Midwest Brazil not covered by other previous studies. Our study provides an understanding of how ZIKV initiates transmission in this region and reveals a complex transmission dynamic between epidemic seasons. Together, our results highlight the utility of genomic, epidemiological, and evolutionary methods to understand mosquito-borne epidemics, revealing how this toolkit can be used to help policymakers prioritize areas to be targeted, especially in the context of finite public health resources.

Experimental evidence for a high rate of maternal-fetal transmission of dengue virus in the presence of antibodies in immunocompromised mice

SummaryBackgroundCongenital disorders associated with prenatal vertical transmission of Zika virus (ZIKV) is well established since the 2016 outbreak in the Americas. However, despite clinical reports of similar mode of transmission for other flaviviruses such as dengue virus (DENV), the phenomenon has not been experimentally explored.MethodsPregnant AG129 mice were infected with DENV1 in the presence or absence of enhancing antibodies at different gestational time points. ZIKV was used for comparison. We quantified viral load in fetus and placentas and performed comprehensive gene expression profiling in the maternal (decidua) and fetal portion of placenta separately.FindingsWe demonstrate in a laboratory experimental setting that DENV can be transmitted vertically in a gestation stage-dependent manner similar to ZIKV, and this incidence drastically increases in the presence of enhancing antibodies. Interestingly, a high rate of DENV fetal infection occurs even though the placental viral load is significantly lower than that found in ZIKV-infected dams. Comprehensive gene expression profiling revealed DENV infection modulates a variety of inflammation-associated genes comparable to ZIKV in decidua and fetal placenta in early pregnancy.InterpretationOur findings suggest that the virus-induced modulation of host gene expression may facilitate DENV to cross the placental barrier in spite of lower viral burden compared to ZIKV. This mouse model may serve to identify the host determinants required for the vertical transmission of flaviviruses and develop appropriate countermeasures.FundingNational Medical Research Council/Open Fund Individual Research Grant MOH-000524 (SW), MOH-000086 and OFIRG20nov-0017 (SGV).

Downregulation of transcriptional activity, increased inflammation, and damage in the placenta following in utero Zika virus infection is associated with adverse pregnancy outcomes.

Zika virus (ZIKV) infection during pregnancy causes serious adverse outcomes to the developing fetus, including fetal loss and birth defects known as congenital Zika syndrome (CZS). The mechanism by which ZIKV infection causes these adverse outcomes and specifically, the interplay between the maternal immune response and ZIKV replication has yet to be fully elucidated. Using an immunocompetent mouse model of transplacental ZIKV transmission and adverse pregnancy outcomes, we have previously shown that Asian lineage ZIKV disrupts placental morphology and induces elevated secretion of IL-1β. In the current manuscript, we characterized placental damage and inflammation during in utero African lineage ZIKV infection. Within 48 hours after ZIKV infection at embryonic day 10, viral RNA was detected in placentas and fetuses from ZIKA infected dams, which corresponded with placental damage and reduced fetal viability as compared with mock infected dams. Dams infected with ZIKV had reduced proportions of trophoblasts and endothelial cells and disrupted placental morphology compared to mock infected dams. While placental IL-1β was increased in the placenta, but not the spleen, within 3 hours post infection, this was not caused by activation of the NLRP3 inflammasome. Using bulk mRNAseq from placentas of ZIKV and mock infected dams, ZIKV infection caused profound downregulation of the transcriptional activity of genes that may underly tissue morphology, neurological development, metabolism, cell signaling and inflammation, illustrating that in utero ZIKV infections causes disruption of pathways associated with CZS in our model.

The tiger mosquito in Lebanon two decades after its introduction: A growing health concern.

The tiger mosquito was introduced to the Eastern region of the Mediterranean basin more than twenty years ago. In Lebanon, it was first observed in 2002 in a limited number of locations mainly from the coastal area of the country. In the absence of national entomological control program, this invasive mosquito became an established species and is now considered in many localities, a source of nuisance because of its human biting behavior. Several entomological surveys were conducted to monitor the geographic spread and the seasonal dynamics of Aedes albopictus by collecting adult stages and by monitoring oviposition activity. Moreover, its susceptibility to the common groups of insecticides was assessed using WHO standard bioassays. Previous vector competence studies revealed that local strains were able to transmit Chikungunya and Dengue viruses. Due to the increased risk of Zika virus introduction in the country, we determined the competence of local populations to transmit this virus. Mapping results showed that Ae. albopictus is mainly spread in the relatively humid western versant of the Mount Lebanon chain reaching 1000m altitude, while it is absent from arid and semi-arid inland areas. Besides, this mosquito is active during 32 weeks from spring till the end of autumn. Local strains of the tiger mosquito are susceptible to pyrethroids and carbamates but resistant to organophosphates and organochlorines. They showed ability to transmit Zika virus; however, only 9% of females were capable to excrete the virus in their saliva at day 28 post infection. Current and previous observations highlight the need to establish a surveillance system in order to control this mosquito and monitor the potential introduction of related diseases.

Clinical Features and Neurodevelopmental Outcomes for Infants with Perinatal Vertical Transmission of Zika Virus, Colombia.

Transplacental transmission of Zika virus has been reported during all trimesters of pregnancy and might lead to central nervous system anomalies, including microcephaly. We report 3 cases of perinatal Zika infection identified during the epidemic in Colombia and provide detailed descriptions of clinical features, diagnosis, and neurodevelopmental outcome at 18 months of age (corrected).

Clinical Features and Neurodevelopmental Outcomes for Infants with Perinatal Vertical Transmission of Zika Virus, Colombia

Clinical Features and Neurodevelopmental Outcomes for Infants with Perinatal Vertical Transmission of Zika Virus, Colombia