Table 3 - uploaded by Ryo Kinoshita
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Objectives:
There has been a growing concern over Zika virus (ZIKV) infection, particularly since a probable link between ZIKV infection during pregnancy and microcephaly in the baby was identified. The present study aimed to estimate a theoretical risk of microcephaly during pregnancy with ZIKV infection in Northeastern Brazil in 2015.
Methods:...
Citations
... The infection with ZIKV during pregnancy causes birth defect of the brain known as microcephaly and other associated complications, including miscarriage, stillbirth and preterm birth. Increased cases of neurologic complications such as Guillain-Barré syndrome, neuropathy and myelitis have been reported in areas affected by ZIKV [1,3,4] . ...
In this paper, we formulate and analyse a nonlinear optimal control problem for a Zika virus (ZIKV) infection model with sexual transmission route. An existing deterministic 11-dimensional autonomous system of differential equations is extended to include five time-dependent control functions, namely personal protection, condom use, vaccination, treatment and spraying of insecticide. The necessary conditions for the existence of optimal control quintuple are shown, and we determine the control strategies to minimize the spread dynamics of the ZIKV in the population at the minimum cost of control implementation. The derived optimality system is solved numerically to demonstrate the effectiveness of the different combinations of the five optimal controls in curtailing the transmission and spread of the disease. More importantly, we conduct a cost-effectiveness analysis on the combinations of at least four optimal controls to ascertain the most cost-effective strategy that can be used to hamper the ZIKV spread in the population.
... A similar phenomenon was observed for the Zika virus (ZIKV) epidemic. After the identification of the probable association between ZIKV infection during pregnancy and microcephaly in 2016 (29)(30)(31), public concern over ZIKV quickly increased in Brazil, where a substantial number of microcephaly cases initially were reported. ...
Japan experienced 2 large rubella epidemics in 2004 and 2012-2014. Because of suboptimal immunization levels, the country has been experiencing a third major outbreak during 2018-2020. We conducted time series analyses to evaluate the effect of the 2012-2014 nationwide rubella epidemic on prefecture-level natality in Japan. We identified a statistically significant decline in fertility rates associated with rubella epidemic activity and increased Google searches for the term "rubella." We noted that the timing of fertility declines in 2014 occurred 9-13 months after peak rubella incidence months in 2013 in 4 prefectures with the highest rubella incidence. Public health interventions should focus on enhancing vaccination campaigns against rubella, not only to protect pregnant women from infection but also to mitigate declines in population size and birth rates.
... A striking wave of microcephaly cases with a 23-week delay to the first ZIKV wave was identified and discussed in [26]. The delay arises because ZIKV infections in the first trimester of pregnancy are most likely to induce microcephaly [21,27,28,29]). ...
... By assuming the GBS-ZIKV risk ratio is constant, we attempted to fit an epidemic model and infer this ratio based on the GBS cases time series. Because of the co-circulation of both dengue fever and ZIKV during the two waves, misdiagnoses of ZIKV could occur [29,27,26], especially given both diseases have similar symptoms. Nevertheless, no GBS induced DENV was reported in the 2015 and 2016 years. ...
Background
Between January 2015 and August 2016, two epidemic waves of Zika virus (ZIKV) disease swept the Northeastern (NE) region of Brazil. As a result, two waves of Guillain-Barré Syndrome (GBS) were observed concurrently. The mandatory reporting of ZIKV disease began region-wide in February 2016, and it is believed that ZIKV cases were significantly under-reported before that. The changing reporting rate has made it difficult to estimate the ZIKV infection attack rate, and studies in the literature vary widely from 17% to > 50%. The same applies to other key epidemiological parameters. In contrast, the diagnosis and reporting of GBS cases were reasonably reliable given the severity and easy recognition of the disease symptoms. In this paper, we aim to estimate the real number of ZIKV cases (i.e., the infection attack rate) and their dynamics in time, by scaling up from GBS surveillance data in NE Brazil.
Methodology
A mathematical compartmental model is constructed that makes it possible to infer the true epidemic dynamics of ZIKV cases based on surveillance data of excess GBS cases. The model includes the possibility that asymptomatic ZIKV cases are infectious. The model is fitted to the GBS surveillance data and the key epidemiological parameters are inferred by using a plug-and-play likelihood-based estimation. We make use of regional weather data to determine possible climate-driven impacts on the reproductive number , and to infer the true ZIKV epidemic dynamics.
Findings and conclusions
The GBS surveillance data can be used to study ZIKV epidemics and may be appropriate when ZIKV reporting rates are not well understood. The overall infection attack rate (IAR) of ZIKV is estimated to be 24.1% (95% confidence interval: 17.1%—29.3%) of the population. By examining various asymptomatic scenarios, the IAR is likely to be lower than 33% over the two ZIKV waves. The risk rate from symptomatic ZIKV infection to develop GBS was estimated as ρ = 0.0061% (95% CI: 0.0050%—0.0086%) which is significantly less than current estimates. We found a positive association between local temperature and the basic reproduction number, . Our analysis revealed that asymptomatic infections affect the estimation of ZIKV epidemics and need to also be carefully considered in related modelling studies. According to the estimated effective reproduction number and population wide susceptibility, we comment that a ZIKV outbreak would be unlikely in NE Brazil in the near future.
... In a 2016 press briefing, the WHO predicted that 3 to 4 million Zika cases were expected in the Americas, 2 and an early article in the New England Journal of Medicine described the disease as "explosive" (Fauci and Morens, 2016). Early estimates of the risk of congenital malformation from Zika infection during pregnancy were thought to be 14% or higher, frequently compared to congenital rubella syndrome ( Nishiura et al., 2016). Entomological maps depicted moderate-to-high abundance of Aedes aegypti throughout US cities (including New York, Philadelphia and Washington, DC), suggesting that the summer of 2016 would bring with it a new mosquito-borne disease (Monaghan et al., 2016). ...
The emergence of Zika virus in 2015 challenged conventional ideas of mosquito-borne diseases, tested the resilience of health systems and embedded itself within local sociocultural worlds, with major implications for environmental, sexual, reproductive and paediatric health. This book explores this complex viral epidemic and situates it within its broader social, epidemiological and historical context in Latin America and the Caribbean. The chapters include a diverse set of case studies from scholars and health practitioners working across the region, from Brazil, Venezuela, Ecuador, Mexico, Colombia, the United States and Haiti. The book explores how mosquito-borne disease epidemics (not only Zika but also Chikungunya, Dengue and malaria) intersect with social change and health gov-ernance. By doing so, the authors reflect on the ways in which situated knowledge and social science approaches can contribute to more effective health policy and practice for mosquito-borne disease threats in a changing world.
... In a 2016 press briefing, the WHO predicted that 3 to 4 million Zika cases were expected in the Americas, 2 and an early article in the New England Journal of Medicine described the disease as "explosive" (Fauci and Morens, 2016). Early estimates of the risk of congenital malformation from Zika infection during pregnancy were thought to be 14% or higher, frequently compared to congenital rubella syndrome (Nishiura et al., 2016). Entomological maps depicted moderate-to-high abundance of Aedes aegypti throughout US cities (including New York, Philadelphia and Washington, DC), suggesting that the summer of 2016 would bring with it a new mosquito-borne disease (Monaghan et al., 2016). ...
... In a 2016 press briefing, the WHO predicted that 3 to 4 million Zika cases were expected in the Americas, 2 and an early article in the New England Journal of Medicine described the disease as "explosive" (Fauci and Morens, 2016). Early estimates of the risk of congenital malformation from Zika infection during pregnancy were thought to be 14% or higher, frequently compared to congenital rubella syndrome (Nishiura et al., 2016). Entomological maps depicted moderate-to-high abundance of Aedes aegypti throughout US cities (including New York, Philadelphia and Washington, DC), suggesting that the summer of 2016 would bring with it a new mosquito-borne disease (Monaghan et al., 2016). ...
... woman is pregnant it should be taken more care for examine whether ZIKA infected or not. Because ZVD during pregnant affect the infants with a disease called microcephaly i.e. a child born with small head, not only this and also congenital Zika syndrome [5]. The ZVD makes pregnancy period a complicated time, where miscarriages and preterm birth also occur. ...
Zika virus a mosquito borne flavivirus disease, which is spreading hastily across all over the world. Nearly 95 countries are infected with Zika, Aedes aegypti Mosquitoes is the source of spreading the virus. Microcephaly, myelitis, Guillain-Barre Syndrome and neuropathy are the causes of ZVD. Miscarriages and preterm birth also possible also occur during the time of infection. To overcome an early prediction system is used for detecting the virus using symptoms. The zika dataset is stored in cloud and in our proposed work a Multilayer Perceptron Neural Network classifier used for predicting the Zika virus. The classifier produces accuracy level of 97% the highest accuracy level. Based on the symptoms ZVD is predicted at earlier stage, if they found as infected RNA test will be taken for the concerned person.
... The majority of papers in the literature estimate this probability to be in this range. However Nishiura et al. [25] estimated a higher risk of up to 100% using data from Brazil. Their estimates depend on the unknown fraction of Zika virus infections among seronegative dengue-like illness cases. ...
In this paper we have adapted a delayed dengue model to Zika. By assuming that the epidemic starts by a single infected individual entering a disease-free population at some initial time t0 we have used the least squares parameter estimation technique in R to estimate the initial time t0 using observed Zika data from Brazil as well as the transmission probabilities of Zika in Brazil between humans and mosquitoes and vice-versa. Different values of Aedes aegypti (A. aegypti) biting rate are used throughout the paper. We have estimated the value of the basic reproduction number for Zika in Brazil and calculated the expected number of cases of microcephaly in newborns as a result of women infected with Zika during pregnancy. We started off with a non-age-structured model then introduced age-structure into the model. However in reality seasonality, in particular temperature and rainfall, have a great impact on the population size of A. aegypti. Hence we repeat both the non-age-structured and age-structured analyses introducing seasonality into the A. aegypti birth function to model the effect of these environmental factors.
... Among these, Miyakawa et al. (2014) calculated the incidence of CRS per 100,000 live births in Vietnam using seroprevalence data. In a similar manner, congenital Zika syndrome with the risk of microcephaly (França et al., 2016) was modeled using the integral equation method (Keegan et al., 2017;Nishiura et al., 2016). In the present study, g t was assumed to follow a gamma distribution with mean m and standard deviation s. ...
Objectives: A rubella epidemic has been ongoing in Japan since August 2018. In the present study, we aimed to predict the likely size of a congenital rubella syndrome (CRS) epidemic during 2018–19. Methods: The expected number of CRS cases was estimated using an integral equation based on age-specific incidence of rubella among adult women, the time delay from gestational age of infection to diagnosis of CRS, and distribution of the mothers’ age at delivery. We used epidemic data during 2012–14 to parameterize the model and applied this in the prediction for 2018–19. Results: In analyzing the 2012–14 epidemic data, the mean delay from the mother's infection to diagnosis was estimated at 24.2 weeks (95% confidence interval (CI): 20.7, 28.1). Applying the parameterized model, together with the more than 480 rubella cases in women in 2018 as well as delayed mother's age at delivery in 2017, we determined that the expected number of CRS cases would be 9.7 (95% CI: 6.5, 12.5) cases. As the epidemic is ongoing, the cumulative number of CRS cases could potentially reach 96.8 (95% CI: 65.3, 125.5) cases, if rubella cases in adult women rose to 10 times the number by week 49 in 2018. Conclusions: CRS is expected to occur an average of 24 weeks following the mother's infection with rubella virus. Accounting for an increase to 650 cases in women by week 5 in 2019, the expected number of CRS cases during 2018–19 has already exceeded 13 cases, as of week 5 in 2019.
... However, the striking and unusually dangerous epidemiology of ZIKV and its unique interactions with humans suggest the presence of a modified underlying molecular makeup of this formidable virus. It has now been firmly established that there is a causal relationship between prenatal ZIKV infection and microcephaly, along with other extensive neurological and brain anomalies (Li et al., 2016a(Li et al., , 2017bMelo et al., 2016;Nishiura et al., 2016). It is likely that the Toll-like receptor 3 (TLR3) is linked to ZIKV neuropathology as TLR3 was upregulated in human ZIKV-infected organoids and mouse neurospheres. ...
The Zika virus (ZIKV) global epidemic prompted the World Health Organization to declare it a 2016 Public Health Emergency of International Concern. The overwhelming experience over the past several years teaches us that ZIKV and the associated neurological complications represent a long-term world-wide challenge to public health. Although the number of ZIKV cases in the Western Hemisphere has dropped since 2016, the need for basic research and anti-ZIKV drug development remains strong. Re-emerging viruses like ZIKV are an ever-present threat in the 21st century where fast transcontinental travel lends itself to viral epidemics. Here, we first present the origin story for ZIKV and review the rapid progress researchers have made toward understanding of the ZIKV pathology and in the design, re-purposing, and testing–particularly in vivo–drug candidates for ZIKV prophylaxis and therapy ZIKV. Quite remarkably, a short, but intensive, drug-repurposing effort has already resulted in several readily available FDA-approved drugs that are capable of effectively combating the virus in infected adult mouse models and, most importantly, in both preventing maternal-fetal transmission and severe microcephaly in newborns in pregnant mouse models.
