scholarly journals Zika virus infection, associated microcephaly, and low yellow fever vaccination coverage in Brazil: is there any causal link?

2016 ◽  
Vol 10 (06) ◽  
pp. 563-566 ◽  
Author(s):  
Luciano Pamplona De Góes Cavalcanti ◽  
Pedro Luiz Tauil ◽  
Carlos Henrique Alencar ◽  
Wanderson Oliveira ◽  
Mauro Martins Teixeira ◽  
...  
Keyword(s):  
High Risk ◽  
Virus Infection ◽  
Yellow Fever ◽  
Vaccination Coverage ◽  
Zika Virus ◽  
Causal Link ◽  
Yellow Fever Vaccine ◽  
Vaccination Rates ◽  
Zika Virus Infection ◽  
Yellow Fever Vaccination

Introduction: Since the end of 2014, Zika virus (ZIKV) infection has been rapidly spreading in Brazil. Methodology: To analyze the possible association of yellow fever vaccine with a protective effect against ZIKV-related microcephaly, the following spatial analyses were performed, using Brazilian municipalities as units: i) yellow fever vaccination coverage in Brazilian municipalities in individuals aged 15-49; ii) reported cases of microcephaly by municipality; and iii) confirmed cases of microcephaly related to ZIKV, by municipality. SaTScan software was used to identify clusters of municipalities for high risk of microcephaly. Results: There were seven significant high risk clusters of confirmed microcephaly cases, with four of them located in the Northeast where yellow fever vaccination rates were the lowest. The clusters harbored only 2.9% of the total population of Brazil, but 15.2% of confirmed cases of microcephaly. Conclusion: We hypothesize that pregnant women in regions with high yellow fever vaccination coverage may pose their offspring to lower risk for development of microcephaly. There is an urgent need for systematic studies to confirm the possible link between low yellow fever vaccination coverage, Zika virus infection and microcephaly.

scholarly journals Yellow Fever Vaccine Protects Resistant and Susceptible Mice Against Zika Virus Infection

2019 ◽  
Author(s):  
Ana C. Vicente Santos ◽  
Francisca H. Guedes-da-Silva ◽  
Carlos H. Dumard ◽  
Vivian N. S. Ferreira ◽  
Igor P. S. da Costa ◽  
...  
Keyword(s):  
Viral Load ◽  
Virus Infection ◽  
Yellow Fever ◽  
Zika Virus ◽  
Large Scale ◽  
Yellow Fever Virus ◽  
Yellow Fever Vaccine ◽  
Effective Vaccine ◽  
Type I ◽  
Zika Virus Infection

AbstractZika virus (ZIKV) emerged as an important infectious disease agent in Brazil in 2016. Infection usually leads to mild symptoms but severe congenital neurological disorders and Guillain-Barré syndrome have been reported following ZIKV exposure. The development of an effective vaccine against Zika virus is a public health priority, encouraging the preclinical and clinical studies of different vaccine strategies. Here, we describe the protective effect of an already licensed attenuated yellow fever vaccine (17DD) on type-I interferon receptor knockout mice (A129) and immunocompetent (BALB/c) mice infected with ZIKV. Yellow fever virus vaccination results in robust protection against ZIKV, with decreased mortality in the A129 mice, a reduction in the cerebral viral load in all mice, and weight loss prevention in the BALB/c mice. Despite the limitation of yellow fever (17DD) vaccine to elicit antibody production and neutralizing activity against ZIKV, we found that YF immunization prevented the development of neurological impairment induced by intracerebral virus inoculation in adult. Although we used two vaccine doses in our protocol, a single dose was protective, reducing the cerebral viral load. Different Zika virus vaccine models have been tested; however, our work shows that an efficient and certified vaccine, available for use for several decades, effectively protects mice against Zika virus infection. These findings open the possibility for using an available and inexpensive vaccine to a large-scale immunization in the event of a Zika virus outbreak.

P004 Retrospective analysis of deceased donor samples for ZIKA virus infection in high-risk population, a three-year study

2017 ◽  
Vol 78 ◽  
pp. 54
Author(s):  
Jennifer McCue ◽  
Yvette Hernandez Rodriguez ◽  
Sally de Echegaray Fores ◽  
Ozzarah Ferrer ◽  
Alexander Pinon-Ramos ◽  
...  
Keyword(s):  
High Risk ◽  
Virus Infection ◽  
Retrospective Analysis ◽  
Zika Virus ◽  
Deceased Donor ◽  
High Risk Population ◽  
Risk Population ◽  
Zika Virus Infection

scholarly journals Prior heterologous flavivirus exposure results in reduced pathogenesis in a mouse model of Zika virus infection

2021 ◽  
Author(s):  
Mariah Hassert ◽  
Tara L. Steffen ◽  
Stephen Scroggins ◽  
Abigail K. Coleman ◽  
Enbal Shacham ◽  
...  
Keyword(s):  
Weight Loss ◽  
Virus Infection ◽  
Disease Severity ◽  
Yellow Fever ◽  
Zika Virus ◽  
Neurological Disease ◽  
Virus Disease ◽  
Zika Virus Infection ◽  
Viral Burden ◽  
Flavivirus Infection

The 2015/16 Zika virus epidemic in South and Central America left the scientific community urgently trying to understand the factors that contribute to Zika virus pathogenesis. Because multiple other flaviviruses are endemic in areas where Zika virus emerged, it is hypothesized that a key to understanding Zika virus disease severity, is to study Zika virus infection in the context of prior flavivirus exposure. Human and animal studies have highlighted the idea that having been previously exposed to a different flavivirus may modulate the immune response to Zika virus. However, it is still unclear how prior flavivirus exposure impacts Zika viral burden and disease. In this murine study, we longitudinally examine multiple factors involved in Zika disease, linking viral burden with increased neurological disease severity, weight loss, and inflammation. We show that prior heterologous flavivirus exposure with dengue virus type 2 or 3, or the vaccine strain of yellow fever, provides protection from mortality in a lethal Zika challenge. However, reduction in viral burden and Zika disease varies depending on the infecting primary flavivirus; with primary Zika infection being most protective from Zika challenge, followed by dengue 2, with yellow fever, and dengue 3 protecting against mortality but showing a more severe disease. This study demonstrates the variation in protective effects of prior flavivirus exposure on Zika virus pathogenesis, and identifies distinct relationships between primary flavivirus infection and the potential for Zika virus disease. IMPORTANCE: The emergence and re-emergence of various vector-borne diseases in recent years highlights the need to understand the mechanisms of protection for each pathogen. In this study, we investigated the impact of prior exposure to Zika, dengue serotypes 2 or 3 or the vaccine strain of yellow fever on pathogenesis and disease outcomes in a mouse model of Zika virus infection. We found that prior exposure to a heterologous flavivirus was protective from mortality, and to varying degrees, prior flavivirus exposure was protective against neurological disease, weight loss, and severe viral burden during a lethal Zika challenge. Using a longitudinal and cross-sectional study design, we were able to link multiple disease parameters including viral burden with neurological disease severity, weight loss, and inflammatory response in the context of flavivirus infection. This study demonstrates a measurable but varied impact of prior flavivirus exposure in modulating flavivirus pathophysiology. Given the cyclic nature of most flavivirus outbreaks, this work will contribute to the forecasting of disease severity for future outbreaks.

The Resurgence of Yellow Fever in Oyo State, Nigeria: What’s the Missing Link?

2021 ◽  
Author(s):  
Bassey Enya Bassey ◽  
Fiona Braka ◽  
Rosemary Onyibe ◽  
Olufunmilola Olawumi Kolude ◽  
Marcus Oluwadare ◽  
...  
Keyword(s):  
High Risk ◽  
Yellow Fever ◽  
Vaccination Coverage ◽  
The State ◽  
World Health ◽  
Yellow Fever Vaccine ◽  
Hemorrhagic Disease ◽  
African Countries ◽  
District Health ◽  
Cross Sectional

Abstract Background:Yellow Fever is an acute viral hemorrhagic disease endemic in tropical Africa and Latin America and transmitted through infected mosquitoes. The renewed onset of yellow fever outbreaks in Nigeria followed a global trend of reports and from other African countries marking the emergence of yellow fever as a brand-new re-emerging global threat in 2016 with giant outbreaks of yellow fever reports in Angola and the Democratic Republic of Congo. Nigeria has been battling successive yellow fever resurgence since September 2017. Yellow Fever disease has no cure, but control is through vaccination and vector control. Eliminating Yellow fever Epidemic (EYE) strategy to improve high risk countries’ prevention, preparedness, detection, management and response to yellow fever outbreaks was developed by WHO in 2017 and launched in Nigeria in April 2018. Yet, poor vaccination coverage continues to be a cause for concern.Materials and Methods:We conducted a retrospective cross-sectional study that examines the resurgence of Yellow fever cases and outbreaks from 2013-2020 in Oyo State, Nigeria. The Yellow Fever data for both surveillance and immunization were the focus of the review. Surveillance data were retrieved from the State’s database reported by all 33 LGAs, maintained by the State and supported by the World Health Organization at the Zonal and State levels. The immunization data were retrieved from District Health Information Software (DHIS_2). The proportion of LGAs reporting at least one case of suspected yellow fever with blood specimen, and the number of suspected cases reported for each year within the period under review was measured. We also assessed the trend of confirmed cases, and the incidence per 100,000 population. Also, suspected cases of yellow fever were categorized into four age groups and their vaccination status assessed. The State’s annual administrative vaccination coverage for yellow fever vaccine was compared with the number of confirmed cases for each year.Results:The proportion of LGAs reporting at least a case of suspected yellow fever, with blood sample collected, ranged from 6.1% to 84.9% between 2014 and 2020 while a total of 9 confirmed (8 cases) and probable (1 case) cases of yellow fever were recorded. However, there were no confirmed cases from the year 2013 to 2016, including 2018 but upward trend of incidence of the disease per 100,000 population from 0% in 2013 through 2018, to 3.5% in 2019 and then to 5.6% in 2020 was observed. 93 of 240 (39%) suspected yellow fever cases reported during the given period were observed to have received yellow fever vaccine Conclusion: In conclusion, the resurgence of yellow fever cases in the State reiterate the State being high risk for yellow fever transmission and underline the need for viable interventions such as environmental hygiene to rid the environment of the disease vector’s ecological niche and improving vaccination coverage to provide population immunity.

scholarly journals Febre amarela: cobertura vacinal na região metropolitana de Belo Horizonte

2019 ◽  
Vol 4 (6) ◽  
pp. 26
Author(s):  
Juliana Araújo do Espírito Santo ◽  
Keli Bahia Felicíssimo Zocratto
Keyword(s):  
Yellow Fever ◽  
Vaccination Coverage ◽  
Vaccine Coverage ◽  
Secondary Data ◽  
The Elderly ◽  
Descriptive Study ◽  
Yellow Fever Vaccine ◽  
National Immunization ◽  
Belo Horizonte ◽  
Yellow Fever Vaccination

Descrever a cobertura vacinal de febre amarela nos últimos cinco anos (2013 a 2017) nos municípios de Belo Horizonte, Nova Lima e Ribeirão das Neves.  Estudo descritivo onde foram utilizados dados secundários coletados em sites oficiais relativos ao período de 2013 a 2017 para os municípios de Belo Horizonte, Nova Lima e Ribeirão das Neves. No período analisado, foram aplicadas 1.687.937 doses da vacina contra febre amarela, sendo que a cobertura vacinal em Belo Horizonte caiu de 80% para 0,09% no ano de 2014. Observou-se maior concentração de doses aplicadas na faixa etária de 15 a 59 anos. Em idosos as doses aplicadas aumentaram de 1.888 para 68.570 no ano de 2017. Ressalta-se que a vacinação aumentou consideravelmente após o início da epidemia em 2016. Considerando os anos analisados, os três municípios mantiveram a cobertura vacinal próxima da meta determinada pelo Programa Nacional de Imunização.Descritores: Febre Amarela, Vacinação, Epidemia.Yellow fever: vaccine coverage in the metropolitan area of Belo HorizonteAbstract: To describe the vaccination coverage of yellow fever in the last five years (2013 to 2017) in the municipalities of Belo Horizonte, Nova Lima and Ribeirão das Neves. A descriptive study using secondary data collected from official sites for the period from 2013 to 2017 for the municipalities of Belo Horizonte, Nova Lima and Ribeirão das Neves. In the analyzed period, 1,687,937 doses of the yellow fever vaccine were applied, and vaccination coverage in Belo Horizonte fell from 80% to 0.09% in 2014. There was a higher concentration of doses applied in the range from 15 to 59 years. In the elderly, the doses increased from 1,888 to 68,570 in the year 2017. It should be emphasized that vaccination increased considerably after the onset of the epidemic in 2016. Considering the years analyzed, the three municipalities-maintained vaccination coverage close to the goal determined by the National Immunization Program.Descriptors: Yellow Fever, Vaccination, Epidemic.Fiebre Amarilla: cobertura vacunal en la región metropolitana de Belo HorizonteResumen: Describir la cobertura vacunal de fiebre amarilla en los últimos cinco años (2013 a 2017) en los municipios de Belo Horizonte, Nova Lima y Ribeirão das Neves. Estudio descriptivo donde se utilizaron datos secundarios recogidos en sitios oficiales relativos al período de 2013 a 2017 para los municipios de Belo Horizonte, Nova Lima y Ribeirão das Neves. En el período analizado, se aplicaron 1.687.937 dosis de la vacuna contra la fiebre amarilla, siendo que la cobertura vacunal en Belo Horizonte bajó del 80% al 0,09% en el año 2014. Se observó una mayor concentración de dosis aplicadas en el rango de 15 a 59 años. En los ancianos las dosis aplicadas aumentaron de 1.888 a 68.570 en el año 2017. Se resalta que la vacunación aumentó considerablemente después del inicio de la epidemia en 2016. Considerando los años analizados, los tres municipios mantuvieron la cobertura vacunal próxima a la meta determinada por el Programa Nacional de Inmunización.Descriptores: Fiebre Amarilla, Vacunación, Epidemia. 

scholarly journals Heterologous flavivirus exposure provides varying degrees of cross-protection from Zika virus in a mouse model of infection

2020 ◽  
Author(s):  
Mariah Hassert ◽  
Stephen Scroggins ◽  
Abigail K. Coleman ◽  
Enbal Shacham ◽  
James D. Brien ◽  
...  
Keyword(s):  
Weight Loss ◽  
Virus Infection ◽  
Mouse Model ◽  
Disease Severity ◽  
Yellow Fever ◽  
Zika Virus ◽  
Neurological Disease ◽  
Zika Virus Infection ◽  
Viral Burden ◽  
Over Time

ABSTRACTThe 2015/16 Zika virus epidemic in South and Central America left the scientific community urgently trying to understand the disease and the factors which modulate Zika virus pathogenesis. Multiple other flaviviruses are endemic in areas where Zika virus emerged in 2015/16. Therefore, it is hypothesized that a key to understanding how Zika virus infection and disease progresses, is to study Zika virus infection in the context of prior flavivirus exposure. Humans and animal studies have highlighted the idea that having been previously exposed to a heterologous flavivirus may modulate the immune response to Zika virus. However, it is still unclear 1) how this impacts viral burden and pathology, and 2) the factors which correlate with the multiple metrics of disease. In this murine study, we longitudinally examine multiple factors involved in Zika disease, linking viral burden over time with increased neurological disease severity and weight loss. We show that prior heterologous flavivirus exposure with dengue virus type 2 or 3, or the vaccine strain of yellow fever, provides protection from mortality in a lethal Zika challenge. Reduction in viral burden and Zika disease in the context of prior flavivirus exposure varies depending on the infecting primary virus; with primary Zika infection being most protective from Zika challenge, followed by dengue 2, yellow fever, and dengue 3. This study demonstrates a protective effect of prior heterologous flavivirus exposure on Zika virus pathogenesis, and defines the relationship between prior flavivirus exposure and the potential for Zika virus disease.IMPORTANCEThe emergence and re-emergence of various vector-borne diseases in recent years highlights the need to understand the mechanisms of protection for each pathogen. In this study, we investigated the impact of prior exposure to Zika, dengue serotypes 2, 3, and the vaccine strain of yellow fever on pathogenesis and disease outcomes in a mouse model of Zika virus infection. We found that prior exposure to a heterologous flavivirus was protective from mortality, neurological disease, weight loss, and severe viral burden during a lethal Zika challenge. Using a longitudinal study design, we were able to link multiple disease parameters including viral burden over time with neurological disease severity and weight loss in the context of heterologous infection. This study demonstrates a role for heterologous flavivirus exposure in modulating flavivirus pathophysiology. Given the cyclic nature of most flavivirus outbreaks, this work will contribute to the forecasting of disease severity for future outbreaks.

Congenital Zika Virus Infection Paradigm: What is in the Wardrobe? A Narrative Review

2019 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Mariam M. Mirambo ◽  
Lucas Matemba ◽  
Mtebe Majigo ◽  
Stephen E. Mshana
Keyword(s):  
Virus Infection ◽  
Neural Tube ◽  
Zika Virus ◽  
English Language ◽  
Case Reports ◽  
Case Series ◽  
Epidemiological Studies ◽  
Ocular Manifestations ◽  
Zika Virus Infection ◽  
N 93

Background: Zika virus infection during pregnancy has been recently associated with congenital microcephaly and other severe neural tube defects. However, the magnitude of confirmed cases and the scope of these anomalies have not been extensively documented. This review focuses on the magnitude of laboratory-confirmed congenital Zika virus cases among probable cases and describing the patterns of congenital anomalies allegedly caused by the Zika virus, information which will inform further research in this area. Methods: We conducted a literature search for English-language articles about congenital Zika virus infection using online electronic databases (PubMed/MEDLINE, POPLINE, Embase, Google Scholar, and Web of Knowledge). The search terms used were, “zika”, “pregnancy”, [year], “microcephaly”, “infants”, “children”, “neonates”, “foetuses”, “neural tube defect”, and “CNS manifestations” in different combinations. All articles reporting cases or case series between January 2015 and December 2016 were included. Data were entered into a Microsoft Excel database and analysed to obtain proportions of the confirmed cases and patterns of anomalies. Results: A total of 24 articles (11 case series, 9 case reports, and 4 others) were found to be eligible and included in this review. These articles reported 919 cases, with or without microcephaly, presumed to have congenital Zika virus infection. Of these cases, 884 (96.2%) had microcephaly. Of the 884 cases of microcephaly, 783 (88.6%) were tested for Zika virus infection, and 216 (27.6%; 95% confidence interval, 24.5% to 30.8%) were confirmed to be Zika virus-positive. In addition to microcephaly, other common abnormalities reported – out of 442 cases investigated – were calcifications of brain tissue (n=240, 54.3%), ventriculomegaly (n=93, 20.8%), cerebellar hypoplasia (n=52, 11.7%), and ocular manifestations (n=46, 10.4%). Conclusion: Based on the available literature, Zika virus infection during pregnancy might lead to a wide array of outcomes other than microcephaly. There is a need for more epidemiological studies in Zika-endemic areas, particularly in Africa, to ascertain the role of Zika virus in causing congenital neurological defects.

Congenital Zika Virus Infection Paradigm: What is in the Wardrobe? A Narrative Review

2019 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Mariam M. Mirambo ◽  
Lucas Matemba ◽  
Mtebe Majigo ◽  
Stephen E. Mshana
Keyword(s):  
Virus Infection ◽  
Neural Tube ◽  
Zika Virus ◽  
English Language ◽  
Case Reports ◽  
Case Series ◽  
Epidemiological Studies ◽  
Ocular Manifestations ◽  
Zika Virus Infection ◽  
N 93

Background: Zika virus infection during pregnancy has been recently associated with congenital microcephaly and other severe neural tube defects. However, the magnitude of confirmed cases and the scope of these anomalies have not been extensively documented. This review focuses on the magnitude of laboratory-confirmed congenital Zika virus cases among probable cases and describing the patterns of congenital anomalies allegedly caused by the Zika virus, information which will inform further research in this area. Methods: We conducted a literature search for English-language articles about congenital Zika virus infection using online electronic databases (PubMed/MEDLINE, POPLINE, Embase, Google Scholar, and Web of Knowledge). The search terms used were, “zika”, “pregnancy”, [year], “microcephaly”, “infants”, “children”, “neonates”, “foetuses”, “neural tube defect”, and “CNS manifestations” in different combinations. All articles reporting cases or case series between January 2015 and December 2016 were included. Data were entered into a Microsoft Excel database and analysed to obtain proportions of the confirmed cases and patterns of anomalies. Results: A total of 24 articles (11 case series, 9 case reports, and 4 others) were found to be eligible and included in this review. These articles reported 919 cases, with or without microcephaly, presumed to have congenital Zika virus infection. Of these cases, 884 (96.2%) had microcephaly. Of the 884 cases of microcephaly, 783 (88.6%) were tested for Zika virus infection, and 216 (27.6%; 95% confidence interval, 24.5% to 30.8%) were confirmed to be Zika virus-positive. In addition to microcephaly, other common abnormalities reported – out of 442 cases investigated – were calcifications of brain tissue (n=240, 54.3%), ventriculomegaly (n=93, 20.8%), cerebellar hypoplasia (n=52, 11.7%), and ocular manifestations (n=46, 10.4%). Conclusion: Based on the available literature, Zika virus infection during pregnancy might lead to a wide array of outcomes other than microcephaly. There is a need for more epidemiological studies in Zika-endemic areas, particularly in Africa, to ascertain the role of Zika virus in causing congenital neurological defects.

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