Zika

26

Feb, 2020

Researching Zika in pregnancy: lessons for global preparedness

 

Authors: Ades AE, Thorne C, Soriano-Arandes A, et al.

Published in: Lancet Infect Dis. 2020 Feb 18

Abstract: Our understanding of congenital infections is based on prospective studies of women infected during pregnancy. The EU has funded three consortia to study Zika virus, each including a prospective study of pregnant women. Another multi-centre study has been funded by the US National Institutes of Health. This Personal View describes the study designs required to research Zika virus, and questions whether funding academics in the EU and USA to work with collaborators in outbreak areas is an effective strategy. 3 years after the 2015–16 Zika virus outbreaks, these collaborations have taught us little about vertical transmission of the virus. In the time taken to approve funding, agree contracts, secure ethics approval, and equip laboratories, Zika virus had largely disappeared. By contrast, prospective studies based on local surveillance and standard-of-care protocols have already provided valuable data. Threats to fetal and child health pose new challenges for global preparedness requiring support for the design and implementation of locally appropriate protocols. These protocols can answer the key questions earlier than externally designed studies and at lower cost. Local protocols can also provide a framework for recruitment of unexposed controls that are required to study less specific outcomes. Other priorities include accelerated development of non-invasive tests, and longer-term storage of neonatal and antenatal samples to facilitate retrospective reconstruction of cohort studies.

25

Feb, 2020

Overview and preliminary results of the ZIKAction vertical transmission study in Jamaica

 

Authors: Celia C.

Published in: Oral presentation at 3rd international Conference on Zika Virus and aedes related infections, February 13th – 16th, 2020– Washington DC, USA.

25

Feb, 2020

Trends in Dengue – The Jamaican experience

 

Authors: Webster-Kerr K.

Published in: Oral presentation at 3rd international Conference on Zika Virus and aedes related infections, February 13th – 16th, 2020– Washington DC, USA.

25

Feb, 2020

Severity and outcomes of Dengue in hospitalized children from five hospitals in Jamaica during the 2018-2019 epidemic: is this due to antibody dependent immune enhancement from ZIKA virus exposure?

 

Authors: Lue A.

Published in: Oral presentation at 3rd international Conference on Zika Virus and aedes related infections, February 13th – 16th, 2020– Washington DC, USA.

14

Jan, 2020

Return of the founder Chikungunya virus to its place of introduction into Brazil is revealed by genomic characterization of exanthematic disease cases

 

Authors: Pereira Gusmão Maia Z, Mota Pereira F, do Carmo Said RF, et al.

Published in: Emerg Microbes Infect. 2020;9(1):53-57

Abstract Between June 2017 and August 2018, several municipalities located in Bahia state (Brazil) reported a large increase in the number of patients presenting with febrile illness similar to that of arboviral infections. Using a combination of portable whole genome sequencing, molecular clock and epidemiological analyses, we revealed the return of the CHIKV-ECSA genotype into Bahia. Our results show local persistence of lineages in some municipalities and the re-introduction of new epidemiological strains from different Brazilian regions, highlighting a complex dynamic of transmission between epidemic seasons and sampled locations. Estimated climate-driven transmission potential of CHIKV remained at similar levels throughout the years, such that large reductions in the total number of confirmed cases suggests a slow, but gradual accumulation of herd-immunity over the 4 years of the epidemic in Bahia after its introduction in 2014. Bahia remains a reservoir of the genetic diversity of CHIKV in the Americas, and genomic surveillance strategies are essential to assist in monitoring and understanding arboviral transmission and persistence both locally and over large distances.

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14

Nov, 2019

Yellow Fever virus reemergence and spread in southeast Brazil, 2016-2019

 

Authors: Giovannetti M, de Mendonca MCL, Fonseca V, et al.

Published in: J Virol. 2019;94(1). pii: e01623-19

Abstract The recent reemergence of yellow fever virus (YFV) in Brazil has raised serious concerns due to the rapid dissemination of the virus in the southeastern region. To better understand YFV genetic diversity and dynamics during the recent outbreak in southeastern Brazil, we generated 18 complete and nearly complete genomes from the peak of the epidemic curve from nonhuman primates (NHPs) and human infected cases across the Espírito Santo and Rio de Janeiro states. Genomic sequencing of 18 YFV genomes revealed the estimated timing, source, and likely routes of yellow fever virus transmission and dispersion during one of the largest outbreaks ever registered in Brazil. We showed that during the recent epidemic, YFV was reintroduced from Minas Gerais to the Espírito Santo and Rio de Janeiro states multiple times between 2016 and 2019. The analysis of data from portable sequencing could identify the corridor of spread of YFV. These findings reinforce the idea that continued genomic surveillance strategies can provide information on virus genetic diversity and transmission dynamics that might assist in understanding arbovirus epidemics.

14

Nov, 2019

Factors predicting the severity of dengue in patients with warning signs in Rio de Janeiro, Brazil (1986–2012)

 

Authors: Goncalves BS, Nogueira RMR, Bispo de Filippis AM, Horta MAP

Published in: Trans R Soc Trop Med Hyg. 2019;113(11):670-677

Background Since 1981, >12 million cases of dengue have been reported in Brazil. Early prediction of severe dengue with no warning signs is crucial to avoid progression to severe dengue. Here we aimed to identify early markers of dengue severity and characterize dengue infection in patients in Rio de Janeiro.
Methods We evaluated early severity markers, serotypes, infection status, number of days of illness and viral loads associated with dengue fever in patients from Rio de Janeiro, Brazil through an observational retrospective study (1986–2012). We compared dengue without warning signs and dengue with warning signs/severe dengue (DWWS/SD). Infection status was classified by enzyme-linked immunosorbent assay and viraemia was quantified by quantitative real-time reverse transcription polymerase chain reaction.
Results The presence of DWWS/ SD was significantly associated with younger age; patients 13–19 y of age had a significantly greater chance of presenting warning signs. Dengue virus type 3 (DENV3) was more likely to induce DWWS/SD, which was more frequent on days 4–5 of illness.
Conclusions DENV3, 4–5 d of illness and 13–19 y of age were early biomarkers of dengue severity. To our knowledge, this was the first study to analyse the characteristics of dengue severity in the state of Rio de Janeiro over 27 y of epidemics since the introduction of DENV.

14

Oct, 2019

Re-introduction of dengue virus serotype 2 in the state of Rio de Janeiro after almost a decade of epidemiological silence

 

Authors: Torres MC, de Bruycker Nogueira F, Fernandes CA, et al.

Published in: PLoS One. 2019;14(12):e0225879

Abstract The Asian/American genotype of dengue virus serotype 2 (DENV-2) has been introduced in Brazil through the state of Rio de Janeiro around 1990, and since then it has been spreading and evolving, leading to several waves of dengue epidemics throughout the country that cause a major public health problem. Of particular interest has been the epidemic of 2008, whose highest impact was evidenced in the state of Rio de Janeiro, with a higher number of severe cases and mortality rate, compared to previous outbreaks. Interestingly, no circulation of DENV-2 was witnessed in this region during the preceding 9-year period. By early 2010, phylogenetic analysis of the 2008 epidemic strain revealed that the outbreak was caused by a new viral lineage of the Asian/American genotype, which was pointed as responsible for the outbreak severity as well. The same scenario is repeating in 2019 in this state; however, only a few cases have been detected yet. To provide information that helps to the understanding of DENV-2 dynamics in the state of Rio de Janeiro, and thereafter contribute to public health control and prevention actions, we employed phylogenetic studies combined with temporal and dynamics geographical features to determine the origin of the current viral strain. To this effect, we analyzed a region of 1626 nucleotides entailing the Envelope/NS1 viral genes. Our study reveals that the current strain belongs to the same lineage that caused the 2008 outbreak, however, it is phylogenetically distant from any Brazilian strain identified so far. Indeed, it seemed to be originated in Puerto Rico around 2002 and has been introduced into the state in late 2018. Taking into account that no DENV-2 case was reported over the last decade in the state (representing a whole susceptible children generation), and the fact that a new viral strain may be causing current dengue infections, these results will be influential in strengthening dengue surveillance and disease control, mitigating the potential epidemiological consequences of virus spread.

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13

Oct, 2019

Follow-up of children with confirmed perinatal Zika Virus (ZIKV) exposure: the first 2 years-experience in the Costa Rican tertiary pediatric hospital

 

Authors: Brenes-Chacón H, Ávila-Agüero ML, Camacho-Badilla K, Naranjo-Zuñiga G, Benavides-Lara A,  Soriano-Fallas A

Published in: ID Week, Washington DC, October 2nd – 6th 2019

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1

Oct, 2019

Experimental infection of pregnant female sheep with Zika Virus during early gestation

 

Authors: Schwarz ER, Pozor MA, Pu R, et al.

Published in: Viruses. 2019;11(9)

Abstract Zika virus (ZIKV) is a vertically and sexually transmissible virus resulting in severe congenital malformation. The goal of this study was to develop an ovine model of ZIKV infection. Between 28–35 days gestation (DG), four pregnant animals were infected with two doses of 6 × 106 PFU of ZIKV; four control animals received PBS. Animals were evaluated for 45 days (D) post-infection (PI) and necropsies were performed. Viral RNA was detected in infected ewe peripheral blood mononuclear cells (PBMC) during the first week PI; however, all fluids and tissues were negative upon culture. Anti-ZIKV IgM (1:400) and neutralizing antibodies were detected in all infected animals. Clinical disease, virus, or ZIKV antibodies were not detected in control ewes. After two weeks PI, fetal loss occurred in two infected animals, and at necropsy, three infected animals had placental petechiation and ecchymosis and one had hydramnion. Fetal morphometrics revealed smaller cranial circumference to crown-rump length ratios (p < 0.001) and relative brain weights (p = 0.038) in fetuses of infected animals compared with control fetuses. Immunophenotyping indicated an increase in B cells (p = 0.012) in infected sheep. Additionally, in vitro experiments using both adult and fetal cell lines demonstrated that ovine cells are highly permissive to ZIKV infection. In conclusion, ZIKV infection of pregnant sheep results in a change in fetal growth and gestational outcomes.

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