Project description:BackgroundIn 2015 and 2016, Colombia had a widespread outbreak of Zika virus. Data from two national population-based surveillance systems for symptomatic Zika virus disease (ZVD) and birth defects provided complementary information on the effect of the Zika virus outbreak on pregnancies and infant outcomes.MethodsWe collected national surveillance data regarding cases of pregnant women with ZVD that were reported during the period from June 2015 through July 2016. The presence of Zika virus RNA was identified in a subgroup of these women on real-time reverse-transcriptase-polymerase-chain-reaction (rRT-PCR) assay. Brain or eye defects in infants and fetuses and other adverse pregnancy outcomes were identified among the women who had laboratory-confirmed ZVD and for whom data were available regarding pregnancy outcomes. We compared the nationwide prevalence of brain and eye defects during the outbreak with the prevalence both before and after the outbreak period.ResultsOf 18,117 pregnant women with ZVD, the presence of Zika virus was confirmed in 5926 (33%) on rRT-PCR. Of the 5673 pregnancies with laboratory-confirmed ZVD for which outcomes had been reported, 93 infants or fetuses (2%) had brain or eye defects. The incidence of brain or eye defects was higher among pregnancies in which the mother had an onset of ZVD symptoms in the first trimester than in those with an onset during the second or third trimester (3% vs. 1%). A total of 172 of 5673 pregnancies (3%) resulted in pregnancy loss; after the exclusion of pregnancies affected by birth defects, 409 of 5426 (8%) resulted in preterm birth and 333 of 5426 (6%) in low birth weight. The prevalence of brain or eye defects during the outbreak was 13 per 10,000 live births, as compared with a prevalence of 8 per 10,000 live births before the outbreak and 11 per 10,000 live births after the outbreak.ConclusionsIn pregnant women with laboratory-confirmed ZVD, brain or eye defects in infants or fetuses were more common during the Zika virus outbreak than during the periods immediately before and after the outbreak. The frequency of such defects was increased among women with a symptom onset early in pregnancy. (Funded by the Colombian Instituto Nacional de Salud and the Centers for Disease Control and Prevention.).
Project description:BACKGROUND:Several Zika virus (ZIKV) outbreaks have occurred since October 2015. Because there is no effective treatment for ZIKV infection, developing an effective surveillance and warning system is currently a high priority to prevent ZIKV infection. Despite Aedes mosquitos having been known to spread ZIKV, the calculation approach is diverse, and only applied to local areas. This study used meteorological measurements to monitor ZIKV infection due to the high correlation between climate change and Aedes mosquitos and the convenience to obtain meteorological data from weather monitoring stations. METHODS:This study applied the Bayesian structured additive regression modeling approach to include spatial interactive terms with meteorological factors and a geospatial function in a zero-inflated Poisson model. The study area contained 32 administrative departments in Colombia from October 2015 to December 2017. Weekly ZIKV infection cases and daily meteorological measurements were collected. Mapping techniques were adopted to visualize spatial findings. A series of model selections determined the best combinations of meteorological factors in the same model. RESULTS:When multiple meteorological factors are considered in the same model, both total rainfall and average temperature can best assess the geographic disparities of ZIKV infection. Meanwhile, a 1-in. increase in rainfall is associated with an increase in the logarithm of relative risk (logRR) of ZIKV infection of at most 1.66 (95% credible interval [CI]?=?1.09, 2.15) as well as a 1?°F increase in average temperature is significantly associated with at most 0.79 (95% CI?=?0.12, 1.22) increase in the logRR of ZIKV. Moreover, after controlling rainfall and average temperature, an independent geospatial function in the model results in two departments with an excessive ZIKV risk which may be explained by unobserved factors other than total rainfall and average temperature. CONCLUSION:Our study found that meteorological factors are significantly associated with ZIKV infection across departments. The study determined both total rainfall and average temperature as the best meteorological factors to identify high risk departments of ZIKV infection. These findings can help governmental agencies monitor at risk areas according to meteorological measurements, and develop preventions in those at risk areas in priority.
Project description:ObjectiveGeographical information systems (GIS) have been extensively used for the development of epidemiological maps of tropical diseases, however not yet specifically for Zika virus (ZIKV) infection.MethodsSurveillance case data of the ongoing epidemics of ZIKV in the Tolima department, Colombia (2015-2016) were used to estimate cumulative incidence rates (cases/100,000 pop.) to develop the first maps in the department and its municipalities, including detail for the capital, Ibagué. The GIS software used was Kosmo Desktop 3.0RC1®. Two thematic maps were developed according to municipality and communes incidence rates.ResultsUp to March 5, 2016, 4,094 cases of ZIKV were reported in Tolima, for cumulated rates of 289.9 cases/100,000 pop. (7.95% of the country). Burden of ZIKV infection has been concentrated in its east area, where municipalities have reported >500 cases/100,000 pop. These municipalities are bordered by two other departments, Cundinamarca (3,778 cases) and Huila (5,338 cases), which also have high incidences of ZIKV infection. Seven municipalities of Tolima ranged from 250-499.99 cases/100,000 pop., of this group five border with high incidence municipalities (>250), including the capital, where almost half of the reported cases of ZIKV in Tolima are concentrated.ConclusionsUse of GIS-based epidemiological maps helps to guide decisions for the prevention and control of diseases that represent significant issues in the region and the country, but also in emerging conditions such as ZIKV.
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:Land use boundaries represent human-physical interfaces where risk of vector-borne disease transmission is elevated. Land development practices, coupled with rural and urban land fragmentation, increases the likelihood that immunologically naïve humans will encounter infectious vectors at land use interfaces. This research consolidated land use classes from the GLC-SHARE dataset; calculated landscape metrics in linear (edge) density, proportion abundance, and patch density; and derived the incidence rate ratios of the Zika virus occurrence in Colombia, South America during 2016. Negative binomial regression was used to evaluate vector-borne disease occurrence counts in relation to Population Density, Average Elevation, Per Capita Gross Domestic Product, and each of three landscape metrics. Each kilometer of border length per square kilometer of area increase in the linear density of the Cropland and Grassland classes is associated with an increase in Zika virus risk. These spatial associations inform a risk reduction approach to rural and urban morphology and land development that emphasizes simple and compact land use geometry that decreases habitat availability for mosquito vectors of Zika virus.
Project description:Long known to be endemic in Africa and Southeast Asia and a rare cause of acute febrile illness, Zika virus (ZIKAV) arose from obscurity when an Asian genotype ZIKAV caused an outbreak of mild febrile illness in 2007 in Yap State, Federated States of Micronesia. Subsequent viral spread in the Pacific led to a large outbreak in French Polynesia commencing in 2013. After its recognition in the Americas through March 2017, the Pan American Health Organization has received reports of >750000 suspected and laboratory-confirmed cases of autochthonous ZIKAV transmission. Outbreaks in most countries in the Americas peaked in early to mid-2016. Increased surveillance in several Southeast Asian counties has led to increased case recognition, including an outbreak in Singapore, and the first reports of birth defects linked to ZIKAV in the region. As of April 2017, the World Health Organization reported 84 countries or territories with current or previous ZIKAV transmission.
Project description:Zika virus (Flavivirus genus) is the first mosquito-borne virus known to cause high rates of microcephaly and abortion in humans. Typically, Zika virus causes a self-limiting, systemic illness; however, the current outbreak of Zika virus in the Americas has been associated with increased rates of fetal malformations and Guillain-Barré syndrome. Very few Zika virus isolates have been described in the literature, and live viruses are needed to perform studies of pathogenesis and to develop vaccines and treatments.We isolated Zika virus, strain FLR, directly from the serum of an individual infected in Barranquilla, Colombia (December, 2015). Here, we describe the patient's clinical course and characterize strain FLR by its growth characteristics in mosquito and mammalian cells and its partial resistance to UV-inactivation. The full genome sequence of FLR was also analyzed (including the 3' un-translated region), to determine its probable geographic origin, and to pinpoint structural differences from other Zika virus strains.We anticipate that the study of this low passage, clinical isolate of Zika virus, which is available for worldwide distribution, will help uncover the mechanisms of viral replication and host immune responses contributing to the varied and sometimes severe clinical presentations seen during the current epidemic in the Americas.
Project description:IntroductionZikavirus (ZIKV) and Chikungunyavirus (CHIKV) can share the same mosquito vector, and co-infections by these viruses can occur in humans. While infections with these viruses share commonalities, CHIKV is unique in causing arthritis and arthralgias that may persist for a year or more. These infections are commonly diagnosed by RT-PCR-based methods during the acute phase of infection. Even with the high specificity and sensitivity characteristic of PCR, false negatives can occur, highlighting the need for additional diagnostic methods for confirmation.Case presentationOn her return to the USA, a traveller to Colombia, South America developed an illness consistent with Zika, Chikungunya and/or Dengue. RT-PCR of her samples was positive only for ZIKV. However, arthralgias persisted for months, raising concerns about co-infection with CHIKV or Mayaro viruses. Cell cultures inoculated with her original clinical samples demonstrated two types of cytopathic effects, and both ZIKV and CHIKV were identified in the supernatants. On phylogenetic analyses, both viruses were found to be related to strains found in Colombia.ConclusionThese findings highlight the need to consider CHIKV co-infection in patients with prolonged rheumatological symptoms after diagnosis with ZIKV, and the usefulness of cell culture as an amplification step for low-viremia blood and other samples.
Project description:Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced an explosive epidemic. However, recent studies indicate that the introduction of ZIKV occurred in late 2013. Cases of microcephaly and deaths associated with ZIKV infection were identified in Brazil in November, 2015.To determine the etiology of three fatal adult cases.Here we report three fatal adult cases of ZIKV disease. ZIKV infection in these patients was confirmed by cells culture and/or real-time reverse transcriptase polymerase chain reaction (RT-qPCR) and by antigen detection using immunohistochemical assay. Samples of brain and other selected organs taken at autopsy from three patients were also analyzed by histopathological and immunohistological examination.The first patient, a 36-year-old man with lupus and receiving prednisone therapy, developed a fulminant ZIKV infection. At autopsy, RT-qPCR of blood and tissues was positive for ZIKV RNA, and the virus was cultured from an organ homogenate. The second patient, a previously healthy female, 16 years of age, presented classic symptoms of Zika fever, but later developed severe thrombocytopenia, anemia and hemorrhagic manifestations and died. A blood sample taken on the seventh day of her illness was positive RT-PCR for ZIKV RNA and research in the serum was positive for antinuclear factor fine speckled (1/640), suggesting Evans syndrome (hemolytic anemia an autoimmune disorder with immune thrombocytopenic purpura) secondary to ZIKV infection. The third patient was a 20-year-old woman hospitalized with fever, pneumonia and hemorrhages, who died on 13days after admission. Histopathological changes were observed in all viscera examined. ZIKV antigens were detected by immunohistochemistry in viscera specimens of patients 1 and 3. These three cases demonstrate other potential complications of ZIKV infection, in addition to microcephaly and Guillain-Barre syndrome (GBS), and they suggest that individuals with immune suppression and/or autoimmune disorders may be at higher risk of developing severe disease, if infected with ZIKV.