Cases Of Zika Virus Infection Research Articles

Epidemiological Characteristics of Zika Virus Infections Imported into Taiwan between 2016 and 2021

Abstract Background: Zika virus is a mosquito-borne virus that has resurfaced. It has been confirmed to cause microcephaly and Guillain–Barré syndrome. The number of Zika virus infections in South America has increased considerably since 2015. Aim: This study confirmed the epidemiological characteristics of the cases of Zika virus infections imported into Taiwan. Methods: Patients with travel history to areas at risk of Zika virus infections and had their blood, urine, or saliva samples tested positive for Zika virus through reverse transcription polymerase chain reaction by the Taiwan Centers for Disease Control were included in this study. Results: Taiwan reported its first case of Zika virus infection in January 2016, and it has reported 26 cases as of December 2021. Most of the patients were men (76.9%, 20/26), aged 20–59 years (73.1%, 19/26), and lived in Northern Taiwan (73.1%, 19/26). Most of the cases were reported in summer and autumn (76.9%, 20/26). The 26 patients included one 4-year-old girl and three teenage boys aged 15–19 years; 22 patients were from Southeast Asia, three patients were from the Americas, and one patient was from Africa. Conclusion: This study is the first to report on the epidemiological characteristics of Zika virus infections imported into Taiwan between 2016 and 2021. These findings can aid policymakers and clinical experts in developing prevention and control measures targeting Zika virus infections, which cause severe illness and imposes a considerable burden on the population.

Epidemiological Aspects of Zika Virus Infection Cases among Overseas Travelers in Korea and Japan

Epidemiological Aspects of Zika Virus Infection Cases among Overseas Travelers in Korea and Japan

Sero-epidemiological study of arbovirus infection following the 2015–2016 Zika virus outbreak in Cabo Verde

In November 2015, cases of Zika virus infection were recorded in Cabo Verde (Africa), originating from Brazil. The outbreak subsided after seven months with 7580 suspected cases. We performed a serological survey (n = 431) in Praia, the capital city, 3 months after transmission ceased. Serum samples were screened for arbovirus antibodies using ELISA techniques and revealed seroconverted individuals with Zika (10.9%), dengue (1–4) (12.5%), yellow fever (0.2%) and chikungunya (2.6%) infections. Zika seropositivity was predominantly observed amongst females (70%). Using a logistic model, risk factors for increased odds of Zika seropositivity included age, self-reported Zika infection, and dengue seropositivity. Serological data from Zika and dengue virus assays were strongly correlated (Spearman’s rs = 0.80), which reduced when using a double antigen binding ELISA (Spearman’s rs = 0.54). Overall, our work improves an understanding of how Zika and other arboviruses have spread throughout the Cabo Verde population. It also demonstrates the utility of serological assay formats for outbreak investigations.

A Major Downregulation of Circulating microRNAs in Zika Acutely Infected Patients: Potential Implications in Innate and Adaptive Immune Response Signaling Pathways.

Zika virus (ZIKV) is an arbovirus mainly transmitted by mosquitos of the genus Aedes. The first cases of ZIKV infection in South America occurred in Brazil in 2015. The infection in humans causes diverse symptoms from asymptomatic to a syndrome-like dengue infection with fever, arthralgia, and myalgia. Furthermore, ZIKV infection during pregnancy is associated with fetal microcephaly and neurological disorders. The identification of host molecular mechanisms responsible for the modulation of different signaling pathways in response to ZIKV is the first step to finding potential biomarkers and therapeutic targets and understanding disease outcomes. In the last decade, it has been shown that microRNAs (miRNAs) are important post-transcriptional regulators involved in virtually all cellular processes. miRNAs present in body fluids can not only serve as key biomarkers for diagnostics and prognosis of human disorders but also contribute to cellular signaling offering new insights into pathological mechanisms. Here, we describe for the first time ZIKV-induced changes in miRNA plasma levels in patients during the acute and recovery phases of infection. We observed that during ZIKV acute infection, among the dysregulated miRNAs (DMs), the majority is with decreased levels when compared to convalescent and control patients. We used systems biology tools to build and highlight biological interactions between miRNAs and their multiple direct and indirect target molecules. Among the 24 DMs identified in ZIKV + patients, miR-146, miR-125a-5p, miR-30-5p, and miR-142-3p were related to signaling pathways modulated during infection and immune response. The results presented here are an effort to open new vistas for the key roles of miRNAs during ZIKV infection.

Dengue and Chikungunya virus circulation in Cameroon and Gabon: molecular evidence among symptomatic individuals.

We report the molecular evidence of dengue virus (DENV) and chikungunya virus (CHIKV) infection in symptomatic individuals in Cameroon and Gabon, respectively. Arthropod-borne viruses (arboviruses) are distributed in the tropical or subtropical regions, with DENV having the highest burden. The morbidity and mortality related to arboviral diseases raise the concern of timely and efficient surveillance and care. Our aim was to assess the circulation of arboviruses [DENV, CHIKV, Zika virus (ZIKV)] among febrile patients in Dschang (West Cameroon) and Kyé-ossi (South Cameroon, border with Gabon and Equatorial Guinea). Dried blood spots were collected from 601 consenting febrile patients, and 194 Plasmodium spp.-negative samples were tested for the molecular detection of cases of DENV, CHIKV and ZIKV infection. Overall, no case of ZIKV infection was found, whereas one case of DENV infection and one case of CHIKV infection were detected in Dschang and Kyé-ossi, respectively, with the CHIKV-infected patient being resident in Gabon. Our findings suggest the need to establish an active surveillance of arbovirus transmission in Cameroon and bordering countries.

VP32.10: Permanent threat or a fleeting scare? A case of Zika virus infection

VP32.10: Permanent threat or a fleeting scare? A case of Zika virus infection

Knowledge and risk perception of vulnerable women on Zika virus infection at primary health care level in Brazil

ABSTRACT Vulnerable low-income groups were most affected by Zika virus (ZIKV)-related neurologic syndrome during the 2014–2016 outbreak in Brazil. Major ZIKV infection response took place in Primary Health Care (PHC), including prevention strategies and risk communication. We aimed to detect knowledge and beliefs, as well as knowledge gaps among vulnerable women at the PHC level. A cross-sectional study was carried out in two low-income urban community settings: a small municipality with few ZIKV infection cases and a large municipality hard-hit by the epidemic. An open-ended data collection instrument centred on ZIKV infection knowledge, sources of information, possible causes, symptoms, risk perception, consequences for pregnant women and PHC point-of-care communication was developed. Interviews were recorded, transcribed and content coded for thematic analysis. Most of the seventy-nine respondents had some knowledge of the disease, acknowledging the vector as the source of infection and associating microcephaly with the disease, but distanced themselves from possible ZIKV infection and related risk. PHC services in both communities did not adequately communicate risk for women and children. In an uncertain future scenario as to disease re-emergence, awareness may be diminished and acquired knowledge lost, configuring a public health challenge that must be overcome.

Exploring for Municipality-Level Socioeconomic Variables Related to Zika Virus Incidence in Colombia.

Colombia experienced an outbreak of Zika virus infection during September 2015 until July 2016. This study aimed to identify the socioeconomic factors that at the municipality level correlate with this outbreak and therefore could have influenced its incidence. An analysis of publicly available, municipality-aggregated data related to eight potential explanatory socioeconomic variables was conducted. These variables are school dropout, low energy strata, social security system, savings capacity, tax, resources, investment, and debt. The response variable of interest in this study is the number of reported cases of Zika virus infection per people (projected) per square kilometer. Binomial regression models were performed. Results show that the best predictor variables of Zika virus occurrence, assuming an expected inverse relationship with socioeconomic status, are “school”, “energy”, and “savings”. Contrary to expectations, proxies of socioeconomic status such as “investment”, “tax”, and “resources” were associated with an increase in the occurrence of Zika virus infection, while no association was detected for “social security” and “debt”. Energy stratification, school dropout rate, and the percentage of the municipality’s income that is saved conformed to the hypothesized inverse relationship between socioeconomic standing and Zika occurrence. As such, this study suggests these factors should be considered in Zika risk modeling.

Updating Zika Diagnostic Methods: The Point-of-Care Approach.

Zika virus (ZIKV) has gained great importance worldwide since the past epidemic that occurred in 2015 in Brazil. Early identification of ZIKV is critical to minimize transmission and prevents potentially devastating consequences, including microcephaly in neonates of infected women, congenital blindness, or Guillain-Barré Syndrome. However, this is not an easy task, considering that approximately 80% of ZIKV infection cases are asymptomatic or oligosymptomatic, there are diverse modes of transmission (vertical transmission is through vectors and horizontal transmission through blood, saliva, semen, and urine from infected people), and the fact that ZIKV has a high identity percentage with other cocirculating Flaviviruses such as dengue. Here, we review ZIKV diagnostic methods, with special emphasis on the development of point-of-care diagnostic assays, since these devices commonly have two important advantages: they provide prompt screening and are affordable.

The impact of contact patterns of sexual networks on Zika virus spread: A case study in Costa Rica

The impact of Zika virus (ZIKV) is a global public health issue and its severity is ongoing. It is primarily transmitted via mosquitoes and sexual contacts. Sexual transmission experiences a longer period and strongly depends on the topological structure of sexual networks. However, relatively little work has been done to explore the characteristics of ZIKV infection in sexual networks, and further control ZIKV by changing contact patterns between individuals. In this paper, using the settings of Costa Rica as a case study, we developed a heterosexual network-based model, to study the effect of changing the degree heterogeneity by the measure of deleting the sexual contacts of individuals with small number but large degree in the sexually active places at different time, on ZIKV spread. We obtained a threshold time, which is later than the peak time of ZIKV infected cases. If applied prior to the threshold time, the measure will inhibit ZIKV infection and lower the final size; surprisingly if past the threshold time, the measure will boost ZIKV infection and increase the final size. In addition, our model yielded higher cumulative infection among females, which is in line with observations. Our results provide some guidelines for preventing and controlling mosquito-human and sexual transmissions against ZIKV, particularly for countries with a high rate of sexually transmitted infections.

Teratogen update: Zika virus and pregnancy.

Zika virus was first identified in Uganda in 1947 but received little attention until 2015 when a large outbreak of Zika virus illness followed by an increased number of babies born with microcephaly occurred in Brazil. Zika virus spread rapidly throughout the Americas, and in 2016 was identified as a cause of microcephaly and other serious birth defects. Since that time, much has been learned about the Zika virus. The virus is primarily spread by the bite of Aedes species mosquitoes; however, other forms of transmission (e.g., sexual and intrauterine) have been recognized. Although postnatal Zika virus infection typically causes mild or no symptoms, effects on infants born to prenatally infected mothers can be severe and include structural birth defects and neurodevelopmental effects. The risk of a structural birth defect among infants born to mothers with confirmed or suspected Zika virus infection during pregnancy has ranged from 5 to 10%. The timing of Zika infection during pregnancy affects risk, with higher risks with the first-trimester infection. Neurodevelopmental effects are seen even in infants who appear normal in the newborn period. Although cases of Zika virus infection have fallen in the Americas, the Zika virus remains an active threat in some regions of the world. The development of a Zika vaccine will require continued focus and investment. Until a Zika vaccine is available, prevention efforts for pregnant women include avoidance of travel to areas with active Zika transmission, avoidance of mosquito bites for those living in or traveling to areas with Zika transmission, and protection against sexual transmission.

Emergence of Zika virus infection in China.

Currently, Zika virus (ZIKV) is spreading across the world and no ZIKV infection cases have ever been reported in China. Here, we aimed to determine whether ZIKV infection exists in China. Blood samples of 273 healthy individuals were collected from Nanning City, Guangxi Province, China in March 2019. We found that 9.5% (26/273) and 1.8% (5/273) of healthy persons were positive to ZIKV total antibody (IgG and/or IgM) IgM antibody, respectively. All ZIKV positive plasma samples were negative to Dengue virus and West Nile virus. Among the ZIKV antibody positive plasma samples, 65.4% (17/26) exhibited neutralizing activity to ZIKV. Followed up studies showed that none had clinical symptoms of ZIKV infection and oversea experience. Together, our study indicates that endemic ZIKV infections emerge in China, which not only suggested that ZIKV posed a potential threat to public health in China, but also expand the ZIKV epidemic areas in East and Southeast Asia.

Prevalence of Zika virus neutralizing antibodies in healthy adults in Vietnam during and after the Zika virus epidemic season: a longitudinal population-based survey

BackgroundBetween 2016 and 2019, 265 cases of Zika virus (ZIKV) infection were reported in Vietnam, predominantly in southern Vietnam. In 2016, a case of ZIKV-associated microcephaly was confirmed in the Central Highlands, and several members of the infant’s family were confirmed to be infected with ZIKV. The study aims to determine the level of immunity to ZIKV in the general population of the ZIKV epidemic region.MethodsA total of 879 serum samples were collected from 801 participants between January 2017 and July 2018, during and after the ZIKV epidemic in Vietnam. The samples were tested for anti-ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG), and anti-dengue virus (DENV) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Plaque-reduction neutralization test (PRNT) for ZIKV was performed on all samples, and for DENV on the samples that ZIKV neutralizing antibody positive.ResultsA total of 83 (10.3%) participants had anti-ZIKV IgM. Of the 83, 6 were confirmed to be ZIKV antibodies positive using PRNT and anti-ZIKV IgG ELISA. Of the 718 participants who were anti-ZIKV IgM negative, a further 3 cases were confirmed as positive for antibodies against ZIKV. Of the 9 participants with ZIKV infection, 5 lived in the same village as the infant with ZIKV-associated microcephaly and the other 4 lived in 2 neighboring communes. Repeat samples were collected from the 83 ZIKV IgM positive participants 1.5 years after the first collection. No new cases of ZIKV infection were detected. In addition, 2 of 3 participants with anti-ZIKV NS1 IgG demonstrated a 4- to 8-fold increase in ZIKV neutralizing antibody titer.ConclusionsZIKV was present in the area around Krong Buk, with the rate of ZIKV-specific antibodies was 1.1% in the community since at least 2016. While the low levels of circulation together with low seroprevalence suggests a limited outbreak in the region, the results also reflect on low levels of protective immunity to Zika within the population. These results provide a better understanding of the current ZIKV epidemic status in the region and demonstrate a need for implementation of more effective ZIKV infection control measures.

Microcephaly Epidemic in Brazil: An Earlier Chapter

Background: The first cases of Zika virus infection and microcephaly in Brazil were reported in 2015. However, phylogenetic studies suggest that the virus may have previously circulated in the country. Methods: The head circumference of 62,298 newborns was analysed to identify cases of microcephaly between 2014 and 2017. We compared the groups of newborns with normal head circumference and those with microcephaly to identify risk factors. A time series with the incidences of microcephaly was analysed to assess the appearance of anomalous values to identify the beginning of the microcephaly epidemic. Data on the incidence of dengue fever were used to develop a control chart, aiming to identify changes in incidence and seasonality that could suggest the circulation of a new arbovirus. Findings: Premature newborns, children of mothers under 20 years of age and those born in 2014 and 2015 had a higher risk of microcephaly. Three quarters with anomalous incidences of microcephaly were identified, the first in 2014 and the others in 2015. The dengue epidemic curve in 2013 shows persistence of high incidences in atypical periods, suggesting the entry of a new virus in the third and fourth quarters. Interpretation: These findings represent epidemiological evidence of the existence of cases of Zika virus between the second quarter of 2013 and the beginning of 2014. The results add new elements to understanding the Zika virus epidemic in the Americas. Funding Statement: No funding was received. Declaration of Interest: Declaration of interests: We declare no competing interests Ethical Approval Statement: The ethics and research committee of the Federal University of Paraiba (2.520.770, CAAE 81168517.6.0000.8069) approved the research.

Adequate Placental Sampling for the Diagnosis and Characterization of Placental Infection by Zika Virus.

The detection of Zika virus (ZIKV) in immunoprivileged anatomical sites, potential sites for viral persistence, may guide the confirmation of undefined cases of ZIKV infection and also bring to light unknown pathways of viral transmission. Thus, this study aimed to characterize ZIKV infection in stratified, standardized placental samples in women with exanthematic febrile manifestations during pregnancy and compare findings to the standard investigation protocol of official health agencies. To this end, a case series of placental findings within a prospective cohort study was conducted over a period of 24 months. Serum/urine were obtained at the time of clinical case identification. Placental sampling was performed following standard investigation protocol (samples of 1.0 cm sent to a reference laboratory) and in a systematic way at various regions, such as chorionic plate, chorionic villi, basal plate, amniotic membrane, and umbilical cord, for subsequent ZIKV identification and quantification. Clinical information was obtained and histological preparation with hematoxylin–eosin staining for morphological evaluation was performed. This case series included 17 placentas systematically collected. Of these, 14 were positive by qRT-PCR for ZIKV, 5 in the umbilical cord, 7 in the amniotic membrane, 7 in the chorionic plate, 13 in the chorionic villi, and 7 in the basal plate, whereas none were reported by the reference laboratory. The most common morphological and anatomopathological findings were increased stromal cellularity, villitis, calcification, maternal vascular malperfusion, placental hypoplasia, and maternal–fetal hemorrhage (intervillous thrombi). Seven women presented positive testing for ZIKV in serological and/or molecular tests during gestation in urine. While viral quantification in urine ranged from 101 to 103 FFU eq/ml, that in different placental regions ranged from 103 to 108 FFU eq/g. Thus, ZIKV can infect different regions of the placenta and umbilical cord of pregnant women, showing that the systematic collection and adequate storage of the placenta is fundamental for the detection of ZIKV in this organ. The detection of ZIKV in the placenta after several months of initial symptoms suggests that this tissue may be a site for viral persistence during pregnancy.

A preliminary survey of Zika virus infection by nucleic acid test in the volunteer blood donor samples in Shenzhen China.

Although Zika virus (ZIKV) infection is mainly transmitted through mosquito bite, it can also be transmitted through blood transfusion. More than 500 000 cases of ZIKV infection were reported in the Americas from 2015 to 2016. Up till now, over 10 cases of imported ZIKV infection have been reported due to frequent international exchanges in the Shenzhen city of Guangdong Province, China. Unfortunately, there were no data on ZIKV infection in Chinese blood donors because it has not been included in routine screening for volunteer blood donors. As such, we performed a preliminary survey of the prevalence of ZIKV infection among volunteer blood donors in Shenzhen, China, to assess the potential risk of ZIKV infection through transfusion. A total of 9626 blood donor samples were collected and ZIKA RNA was detected by transcription-mediated amplification (TMA) nucleic acid amplification method with the Panther nucleic acid automatic analysis system of Grifols,Spain, including Procleix ZIKV Assay reagent. All the experiments in this study were conducted in accordance with the standard operating procedure of the blood center. Of the 9626 donor blood samples tested, none of these samples was Zika RNA reactive. There was no positive case from ZIKV RNA screening in this preliminary survey. There was no ZIKV presence in blood donors in Shenzhen, China, from this preliminary survey. The potential risk of ZIKV infection by transfusion is low in Shenzhen at this moment. Therefore, there is no need to add ZIKV nucleic acid test as a routine screening for blood donors.

Assessment of Contraceptive Needs and Improving Access in the U.S.-Affiliated Pacific Islands in the Context of Zika.

Scientific evidence demonstrated a causal relationship between Zika virus infection during pregnancy and neurologic abnormalities and other congenital defects. The U.S. government's Zika Virus Disease Contingency Response Plan recognized the importance of preventing unintended pregnancy through access to high-quality family planning services as a primary strategy to reduce adverse Zika-related birth outcomes during the 2016-2017 Zika virus outbreak. The U.S.-affiliated Pacific Islands (USAPI) includes three U.S. territories: American Samoa, the Commonwealth of the Northern Mariana Islands, and Guam, and three independent countries in free association with the United States: the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau. Aedes spp. mosquitoes, the primary vector that transmits Zika virus, are common across the Pacific Islands, and in 2016, laboratory-confirmed cases of Zika virus infection in USAPI were reported. CDC conducted a rapid assessment by reviewing available reproductive health data and discussing access to contraception with family planning providers and program staff in all six USAPI jurisdictions between January and May 2017. In this report, we summarize findings from the assessment; discuss strategies developed by jurisdictions to respond to identified needs; and describe a training that was convened to provide technical assistance to USAPI. Similar rapid assessments may be used to identify training and technical assistance needs in other emergency preparedness and response efforts that pose a risk to pregnant women and their infants.

Review of neuroimaging findings in congenital Zika virus syndrome and its relation to the time of infection.

Many original articles and case series have been published emphasizing the neuroimaging findings of congenital Zika virus (ZIKV) infection. The majority of these studies do not follow a neuroradiological methodology to describe malformations and brain abnormalities resulting from ZIKV infection. The cause-and-effect correlation between the gestational period of maternal infection and the severity of encephalic changes at birth has rarely been reported. A systematic literature review was conducted on the neuroimaging findings in children affected with microcephaly due to ZIKV. PubMed, Cochrane Library and Web of Science were searched for full-text articles published up to July 2019. Duplicate entries were removed. Two independent reviewers performed a quality assessment of all the studies included. A total of 2214 publications were identified. Of these 2170 were excluded by analysis of titles and abstracts, resulting in the inclusion of only eight articles. Chi-square and Fisher's exact tests were performed with a 95% confidence interval to verify the statistically significant differences in the neuroradiological findings between the cases of ZIKV infection in the first or second trimester of gestation. The studies published so far have described image abnormalities at random, without utilizing any pre-established neuroradiological criteria, and imaging modalities with different sensitivity and accuracy have been used, which jeopardizes a reliable and adequate statistical analysis. Neuroimaging abnormalities are much more prevalent and severe when the infection by ZIKV is contracted in the first or second trimester of pregnancy.

Analysis of the spatial distribution of cases of Zika virus infection and congenital Zika virus syndrome in a state in the southeastern region of Brazil: Sociodemographic factors and implications for public health.

ObjectiveTo perform spatial distribution analysis of reported cases of Zika virus and congenital Zika syndrome (CZS) in the state of Espírito Santo, Brazil, by neighborhood, and relate the results to sociodemographic indicators and implications for the health process.MethodsAn ecological study using data from the 2016 National Notifiable Diseases Surveillance System, epidemiological records, and information on neighborhoods of families confirmed with CZS from qualitative field research.ResultsSociodemographic indicators were analyzed in three distinct groups: general population with Zika virus, pregnant women with Zika virus, and cases of CZS visited. For the three groups, average literacy rates were 71.1%, 71.0%, and 68.3%; the average income per minimum wage was 1.4, 1.1, and 1.4; sanitary sewage coverage was 75.6%, 76.1%, and 71.4%; garbage coverage was 90.8%, 91.2%, and 89.2%; and water supply was 93.8%, 94.1% and 93.8%, respectively. Socioeconomic indicators showed no significant differences between groups, although they were above the national average. A nonsignificant variation of 68.3%–71.1% was seen in the average literacy level above 15 years of age.ConclusionSocioeconomic and demographic indicators of cases of Zika virus infection and CZS may indicate that the outbreak had different impacts according to class, social group, or gender, reflecting the persistence and social geography of inequality in Brazil.

Estimation of the Size of Dengue and Zika Infection Among Korean Travelers to Southeast Asia and Latin America, 2016-2017.

ObjectivesTo estimate the number and risk of imported infections resulting from people visiting Asian and Latin American countries.MethodsThe dataset of visitors to 5 Asian countries with dengue were analyzed for 2016 and 2017, and in the Philippines, Thailand and Vietnam, imported cases of zika virus infection were also reported. For zika virus, a single imported case was reported from Brazil in 2016, and 2 imported cases reported from the Maldives in 2017. To understand the transmissibility in 5 Southeast Asian countries, the estimate of the force of infection, i.e., the hazard of infection per year and the average duration of travel has been extracted. Outbound travel numbers were retrieved from the World Tourism Organization, including business travelers.ResultsThe incidence of imported dengue in 2016 was estimated at 7.46, 15.00, 2.14, 4.73 and 2.40 per 100,000 travelers visiting Philippines, Indonesia, Thailand, Malaysia and Vietnam, respectively. Similarly, 2.55, 1.65, 1.53, 1.86 and 1.70 per 100,000 travelers in 2017, respectively. It was estimated that there were 60.1 infections (range: from 16.8 to 150.7 infections) with zika virus in Brazil, 2016, and 345.6 infections (range: from 85.4 to 425.5 infections) with zika virus in the Maldives, 2017.ConclusionThis study emphasizes that dengue and zika virus infections are mild in their nature, and a substantial number of infections may go undetected. An appropriate risk assessment of zika virus infection must use the estimated total size of infections.