Project description:Zika virus (ZIKV) had remained a relatively obscure flavivirus until a recent series of outbreaks accompanied by unexpectedly severe clinical complications brought this virus into the spotlight as causing an infection of global public health concern. In this review, we discuss the history and epidemiology of ZIKV infection, recent outbreaks in Oceania and the emergence of ZIKV in the Western Hemisphere, newly ascribed complications of ZIKV infection, including Guillain-Barré syndrome and microcephaly, potential interactions between ZIKV and dengue virus, and the prospects for the development of antiviral agents and vaccines.
Project description:Zika virus (ZIKV) has been presumed to be endemic in Southeast Asia (SEA), with a low rate of human infections. Although the first ZIKV evidence was obtained in the 1950s through serosurveys, the first laboratory-confirmed case was only detected in 2010 in Cambodia. The epidemiology of ZIKV in SEA remains uncertain because of the scarcity of available data. From 2016, subsequent to the large outbreaks in the Pacific and Latin America, several Asian countries started reporting increasing numbers of confirmed ZIKV patients, but no global epidemiological assessment is available to date. Here, with the aim of providing information on ZIKV circulation and population immunity, we conducted a seroprevalence study among blood donors in Vientiane, Laos. Sera from 359 asymptomatic consenting adult donors in 2003-2004 and 687 in 2015 were screened for anti-ZIKV IgG using NS1 ELISA assay (Euroimmun, Luebeck, Germany). Positive and equivocal samples were confirmed for anti-ZIKV-neutralizing antibodies by virus neutralization tests. Our findings suggest that ZIKV has been circulating in Vientiane over at least the last decade. Zika virus seroprevalence observed in the studied blood donors was low, 4.5% in 2003-2004 with an increase in 2015 to 9.9% (P = 0.002), possibly reflecting the increase of ZIKV incident cases reported over this period. We did not observe any significant difference in seroprevalence according to gender. With a low herd immunity in the Vientiane population, ZIKV represents a risk for future large-scale outbreaks. Implementation of a nationwide ZIKV surveillance network and epidemiological studies throughout the country is needed.
Project description:In December 2013, chikungunya virus (CHIKV) was isolated for the first time in the Western Hemisphere (WH) during an epidemic on the island of St. Martin. Subsequently, the virus has spread to 42 countries or territories in the Caribbean, Central, South, and North America. In this study, we have determined the full genomic sequences of 29 temporally and geographically diverse CHIKV strains from 16 countries of the WH. Phylogenetic analyses revealed minimal evolution among compared emergent CHIKV strains of the New World.
Project description:Zika virus (ZIKV) is an important flavivirus infection. Although ZIKV infection is rarely fatal, risk for severe disease in adults is not well described. Our objective was to describe the spectrum of illness in U.S. Veterans with ZIKV infection.Case series study including patients with laboratory-confirmed or presumed positive ZIKV infection in all Veterans Health Administration (VHA) medical centers. Adjusted odds ratios of clinical variables associated with hospitalization and neurologic complications was performed.Of 1,538 patients tested between 12/2015-10/2016 and observed through 3/2017, 736 (48%) were RT-PCR or confirmed IgM positive; 655 (89%) were male, and 683 (93%) from VA Caribbean Healthcare System (VACHCS). Ninety-four (13%) were hospitalized, 91 (12%) in the VACHCS. Nineteen (3%) died after ZIKV infection. Hospitalization was associated with increased Charlson co-morbidity index (adjusted odds ratio [OR] 1.2; 95% confidence interval [CI], 1.1-1.3), underlying connective tissue disease (OR, 29.5; CI, 3.6-244.7), congestive heart failure (OR, 6; CI, 2-18.5), dementia (OR, 3.6; CI, 1.1-11.2), neurologic symptom presentation (OR, 3.9; CI, 1.7-9.2), leukocytosis (OR, 11.8; CI, 4.5-31), thrombocytopenia (OR, 7.8; CI, 3.3-18.6), acute kidney injury (OR, 28.9; CI, 5.8-145.1), or using glucocorticoids within 30 days of testing (OR, 13.3; CI 1.3-133). Patients presenting with rash were less likely to be hospitalized (OR, 0.29; CI, 0.13-0.66). Risk for neurologic complications increased with hospitalization (OR, 5.9; CI 2.9-12.2), cerebrovascular disease (OR 4.9; CI 1.7-14.4), and dementia (OR 2.8; CI 1.2-6.6).Older Veterans with multiple comorbidities or presenting with neurologic symptoms were at increased risk for hospitalization and neurological complications after ZIKV infection.
Project description:Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016. Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present.
Project description:Penaeid shrimp aquaculture is an important industry in the Americas, and the industry is based almost entirely on the culture of the Pacific White Shrimp, Litopenaeus vannamei. Western Hemisphere shrimp farmers in 14 countries in 2004 produced more than 200,000 metric tons of shrimp, generated more than $2 billion in revenue, and employed more than 500,000 people. Disease has had a major impact on shrimp aquaculture in the Americas since it became a significant commercial entity in the 1970s. Diseases due to viruses, rickettsial-like bacteria, true bacteria, protozoa, and fungi have emerged as major diseases of farmed shrimp in the region. Many of the bacterial, fungal and protozoan caused diseases are managed using improved culture practices, routine sanitation, and the use of chemotherapeutics. However, the virus diseases have been far more problematic to manage and they have been responsible for the most costly epizootics. Examples include the Taura syndrome pandemic that began in 1991-1992 when the disease emerged in Ecuador, and the subsequent White Spot Disease pandemic that followed its introduction to Central America from Asia in 1999. Because of their socioeconomic significance to shrimp farming, seven of the nine crustacean diseases listed by the World Animal Organization (OIE) are virus diseases of shrimp. Of the seven virus diseases of penaeid shrimp, five are native to the Americas or have become enzootic following their introduction. The shrimp virus diseases in the Americas are increasingly being managed by exclusion using a combination of biosecurity and the practice of culturing domesticated specific pathogen-free (SPF) stocks or specific pathogen-resistant (SPR) stocks. Despite the significant challenges posed by disease, the shrimp farming industry of the Americas has responded to the challenges posed by disease and it has developed methods to manage its diseases and mature into a sustainable industry.
Project description:Zika virus (ZIKV) is a mosquito-borne pathogen that recently caused a major epidemic in the Americas. Although the majority of ZIKV infections are asymptomatic, the virus has been associated with birth defects in fetuses and newborns of infected mothers as well as neurological complications in adults. We performed a descriptive analysis on approximately 106,000 suspected and laboratory-confirmed cases of Zika virus disease (ZVD) that were reported during the 2015-2017 epidemic in Colombia. We also analyzed a dataset containing patients with neurological complications and recent febrile illness compatible with ZVD. Females had higher cumulative incidence of ZVD than males. Compared to the general population, cases were more likely to be reported in young adults (20 to 39 years of age). We estimated the cumulative incidence of ZVD in pregnant females at 3,120 reported cases per 100,000 population (95% CI: 3,077-3,164), which was considerably higher than the incidence in both males and non-pregnant females. ZVD cases were reported in all 32 departments. Four-hundred and eighteen patients suffered from ZIKV-associated neurological complications, of which 85% were diagnosed with Guillain-Barré syndrome. The median age of ZIKV cases with neurological complications was 12 years older than that of ZVD cases. ZIKV-associated neurological complications increased with age, and the highest incidence was reported among individuals aged 75 and older. Even though neurological complications and deaths due to ZIKV were rare in this epidemic, better risk communication is needed for people living in or traveling to ZIKV-affected areas.
Project description:Background:Zika virus (ZIKV) is an emerging mosquito-borne disease that can cause severe birth defects if contracted congenitally. Since late 2015, there has been a large increase in the number of travel-related cases of Zika virus infection in Canada. Objective:The objective of this study was to describe the epidemiology of travel-related Zika cases in Canada from October 2015 to June 2017 and review them in the context of the international outbreak in the Americas. Methods:Zika virus infections were confirmed by polymerase chain reaction (PCR) detection of viral RNA and/or the serological identification of ZIKV-specific antibodies in serum. Cases of ZIKV infection were identified by provincial and territorial health authorities, and reported on a regular basis to the Public Health Agency of Canada (PHAC). Case information requested included date of illness onset, age category, sex, pregnancy status, and location(s) and dates of travel. Estimates for the monthly number of Canadians travelling outside of Canada to other countries in the Americas were obtained from Statistics Canada and the International Air Transport Association (IATA). Data to produce the epidemic curves of autochthonous cases for each region of the Americas were extracted from country-specific epidemic curves on the Pan American Health Organization website. Results:As of June 7, 2017, 513 laboratory confirmed cases and two Zika-related birth/fetal anomalies were reported across all 10 provinces. Illness in Canadian travellers generally coincided with outbreak intensity in the country of exposure rather than travel volume. There has been no evidence of autochthonous (local) transmission in Canada. Currently, cases are on the decline both in Canada and internationally. Conclusion:The surge in Canadian ZIKV infections in 2016 was directly related to the incursion and spread of ZIKV into the Americas. Although cases are now on the decline worldwide, it remains to be seen whether a resurgence of cases in previously affected or new areas will occur. Both outbreak intensity and seasonality of ZIKV transmission should be monitored over time in order to inform the timing of public health education campaigns, as some may turn out to be more effective in the off-peak travel season when the risk of disease transmission may be higher. Ongoing education and awareness among travellers, particularly for pregnant women and those planning pregnancies, is still indicated.
Project description:Zika virus is an Aedes-borne Flavivirus causing fever, arthralgia, myalgia rash, associated with Guillain-Barré syndrome and suspected to induce microcephaly in the fetus. We report here the complete coding sequence of the first characterized Caribbean Zika virus strain, isolated from a patient from Martinique in December, 2015.
Project description:During 2015-2016, Cape Verde, an island nation off the coast of West Africa, experienced a Zika virus (ZIKV) outbreak involving 7,580 suspected Zika cases and 18 microcephaly cases. Analysis of the complete genomes of 3 ZIKV isolates from the outbreak indicated the strain was of the Asian (not African) lineage. The Cape Verde ZIKV sequences formed a distinct monophylogenetic group and possessed 1-2 (T659A, I756V) unique amino acid changes in the envelope protein. Phylogeographic and serologic evidence support earlier introduction of this lineage into Cape Verde, possibly from northeast Brazil, between June 2014 and August 2015, suggesting cryptic circulation of the virus before the initial wave of cases were detected in October 2015. These findings underscore the utility of genomic-scale epidemiology for outbreak investigations.