scholarly journals International travelers and genomics uncover a ‘hidden’ Zika outbreak

2018 ◽  
Author(s):  
Nathan D. Grubaugh ◽  
Sharada Saraf ◽  
Karthik Gangavarapu ◽  
Alexander Watts ◽  
Amanda L. Tan ◽  
...  
Keyword(s):  
Zika Virus ◽  
Public Health Surveillance ◽  
Mosquito Control ◽  
Herd Immunity ◽  
Virus Transmission ◽  
The United States ◽  
Control Measures ◽  
Local Case ◽  
Peak Transmission ◽  
And Control

AbstractThe ongoing Zika epidemic in the Americas has challenged public health surveillance, response, and control systems. Even as the epidemic appears to be near its end in the Americas, it is unclear whether substantial Zika virus transmission may still be ongoing. This issue is exacerbated by large discrepancies in local case reporting and significant delays in detecting outbreaks due to surveillance gaps. To uncover locations with lingering outbreaks in the Americas, we investigated travel-associated Zika cases diagnosed in the United States and Europe to identify signatures of transmission dynamics that were not captured by local reporting. We found that a large and unreported Zika outbreak occurred in Cuba during 2017, a year after peak transmission in neighboring countries, with cases still appearing in 2018. By sequencing Zika virus from infected travelers, we show that the 2017 outbreak in Cuba was sparked by long-lived lineages of Zika virus introduced from multiple places in the Americas a year prior. Our data suggest that while aggressive mosquito control in Cuba may initially have been effective at mitigating Zika virus transmission, in the absence of vaccines, herd immunity, or strong international coordination, such control measures may need to be maintained to be effective. Our study highlights how Zika virus may still be ‘silently’ spreading in the Americas and provides a framework for more accurately understanding outbreak dynamics.

scholarly journals Emergence of Epidemic Zika Virus Transmission and Congenital Zika Syndrome: Are Recently Evolved Traits to Blame?

mBio ◽  
2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Scott C. Weaver
Keyword(s):  
Zika Virus ◽  
Virus Transmission ◽  
Severe Infection ◽  
Human Infection ◽  
Conclusive Evidence ◽  
Control Measures ◽  
Human Populations ◽  
Reverse Genetic ◽  
Congenital Zika Syndrome ◽  
And Control

ABSTRACT The mechanisms responsible for the dramatic emergence of Zika virus (ZIKV), accompanied by congenital Zika syndrome and Guillain-Barré syndrome (GBS), remain unclear. However, two hypotheses are prominent: (i) evolution for enhanced urban transmission via adaptation to mosquito vectors, or for enhanced human infection to increase amplification, or (ii) the stochastic introduction of ZIKV into large, naive human populations in regions with abundant Aedes aegypti populations, leading to enough rare, severe infection outcomes for their first recognition. Advances in animal models for human infection combined with improvements in serodiagnostics, better surveillance, and reverse genetic approaches should provide more conclusive evidence of whether mosquito transmission or human pathogenesis changed coincidentally with emergence in the South Pacific and the Americas. Ultimately, understanding the mechanisms of epidemic ZIKV emergence, and its associated syndromes, is critical to predict future risks as well as to target surveillance and control measures in key locations.

scholarly journals Using paired serology and surveillance data to quantify dengue transmission and control during a large outbreak in Fiji

2018 ◽  
Author(s):  
Adam J Kucharski ◽  
Mike Kama ◽  
Conall H Watson ◽  
Maite Aubry ◽  
Sebastian Funk ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Virus Transmission ◽  
Surveillance Data ◽  
Control Measures ◽  
Major Health ◽  
Dengue Transmission ◽  
Before And After ◽  
Large Outbreak ◽  
And Control ◽  
Additional Reduction

AbstractDengue is a major health burden, but it can be challenging to examine transmission dynamics and evaluate control measures because outbreaks depend on multiple factors, including human population structure, prior immunity and climate. We combined population-representative paired sera collected before and after the major 2013/14 dengue-3 outbreak in Fiji with surveillance data to determine how such factors influence dengue virus transmission and control in island settings. Our results suggested the 10-19 year-old age group had the highest risk of acquiring infection, but we did not find strong evidence that other demographic or environmental risk factors were linked to seroconversion. Mathematical modelling showed that temperature-driven variation in transmission and herd immunity could not fully explain observed dynamics. However, there was evidence of an additional reduction in transmission coinciding with a vector clean-up campaign, which may have contributed to the decline in cases and prevented transmission continuing into the following season.

Vectors, Hosts, and Control Measures for Zika Virus in the Americas

EcoHealth ◽  
2017 ◽  
Vol 14 (4) ◽  
pp. 821-839 ◽  
Author(s):  
Sarah J. Thompson ◽  
John M. Pearce ◽  
Andrew M. Ramey
Keyword(s):  
Zika Virus ◽  
Control Measures ◽  
And Control

scholarly journals Times to Key Events in the Course of Zika Infection and their Implications for Surveillance: A Systematic Review and Pooled Analysis

2016 ◽  
Author(s):  
Justin Lessler ◽  
Cassandra T. Ott ◽  
Andrea C. Carcelen ◽  
Jacob M. Konikoff ◽  
Joe Williamson ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Supply ◽  
Zika Virus ◽  
Blood Donation ◽  
Case Reports ◽  
Fold Increase ◽  
Pooled Analysis ◽  
Control Measures ◽  
History Of ◽  
And Control

Background Evidence suggests that Zika virus has driven a 10-fold increase in babies born with microcephaly in Brazil, prompting the WHO to declare a Public Health Emergency of International Concern. However, little is known about the natural history of infection. These data are critical for implementation of surveillance and control measures such as protecting the blood supply. Methods We conducted a systematic review and pooled analysis to estimate the distribution of times from Zika infection to symptom onset, seroconversion, and viral clearance, and analyzed their implications for surveillance and blood supply safety. Results Based on 25 case reports, we estimate the median incubation period of Zika virus infection is 5.9 days (95% CI: 4.4-7.6), and that 95% of cases will develop symptoms by 11.1 days post-infection (95% CI: 7.6-18.0). On average seroconversion occurs 9.0 days (95% CI, 7.0-11.6) after infection, and virus is detectable in blood for 9.9 days (95% CI: 6.8-21.4). In 5% of cases detectable virus persists for over 18.9 days (95% CI: 12.6-79.5). The baseline (no screening) risk of a blood donation being infected with Zika increases by approximately 1 in 10,000 for every 1 per 100,000 person-days increase in Zika incidence. Symptom based screening reduces this by 7% (RR 0.93, 93% CI 0.86-0.99), and antibody screening by 29% (RR 0.71, 95% CI: 0.28-0.88). Conclusions Symptom or antibody-based surveillance can do little to reduce the risk of Zika contaminated blood donations. High incidence areas may consider PCR testing to identify lots safe for use in pregnant women.

scholarly journals Readiness for an Increase in Congenital Zika Virus Infections in the United States: Geographic Distance to Pediatric Subspecialist Care

2018 ◽  
Vol 13 (03) ◽  
pp. 476-486 ◽  
Author(s):  
Jeanne Bertolli ◽  
Joseph Holbrook ◽  
Nina D. Dutton ◽  
Bryant Jones ◽  
Nicole F. Dowling ◽  
...  
Keyword(s):  
United States ◽  
Zika Virus ◽  
Full Range ◽  
Geographic Distance ◽  
Virus Transmission ◽  
The United States ◽  
Travel Distance ◽  
Mosquito Vector ◽  
Children's Hospital ◽  
Children’S Hospital

ABSTRACTObjectiveThe study’s purpose was to investigate readiness for an increase in the congenital Zika infection (CZI) by describing the distribution of pediatric subspecialists needed for the care of children with CZI.MethodsWe applied county-level subspecialist counts to US maps, overlaying the geocoded locations of children’s hospitals to assess the correlation of hospital and subspecialist locations. We calculated travel distance from census tract centroids to the nearest in-state children’s hospital by state (with/without > 100 reported adult Zika virus cases) and by regions corresponding to the likely local Zika virus transmission area and to the full range of the mosquito vector. Travel distance percentiles reflect the population of children < 5 years old.ResultsOverall, 95% of pediatric subspecialists across the United States are located in the same county or neighboring county as a children’s hospital. In the states where Zika virus transmission is likely, 25% of children must travel more than 50 miles for subspecialty care; in one state, 50% of children must travel > 100 miles.ConclusionThe travel distance to pediatric subspecialty care varies widely by state and is likely to be an access barrier in some areas, particularly states bordering the Gulf of Mexico, which may have increasing numbers of CZI cases. (Disaster Med Public Health Preparedness. 2019;13:476-486)

Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

2014 ◽  
Vol 147 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Elin C. Maki ◽  
Lee W. Cohnstaedt
Keyword(s):  
Large Scale ◽  
Mosquito Control ◽  
Mosquito Species ◽  
Local Level ◽  
The United States ◽  
Mosquito Vector ◽  
Culex Tarsalis ◽  
Aedes Vexans ◽  
Control Programmes ◽  
And Control

AbstractSampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method for large-scale sampling of two mosquito species using crowdsourcing to network with these local and regional programmes is described. A total of 961 mosquito vector and control districts, health departments, and individual collectors across the United States of America and Canada were contacted in 2011 and 2012 of which 9% positively responded by sending mosquitoes. In total, 1101 unique population samples of Aedes vexans (Meigen) and Culex tarsalis Coquillett were collected throughout their range in these two countries. Aedes vexans outgroup samples were also submitted from Europe and Asia. This is the largest crowd-sourced collection of samples to date.

scholarly journals A Survey of Program Capacity and Skills of Florida Mosquito Control Districts to Conduct Arbovirus Surveillance and Control

2020 ◽  
Vol 36 (2) ◽  
pp. 99-106
Author(s):  
Imelda K. Moise ◽  
Rui-De Xue ◽  
Leo C. Zulu ◽  
John C. Beier
Keyword(s):  
Vector Control ◽  
Mosquito Control ◽  
Control Measures ◽  
Fiscal Year ◽  
Surveillance Systems ◽  
Mosquito Surveillance ◽  
Staffing Levels ◽  
Routine Surveillance ◽  
Timely Access ◽  
And Control

ABSTRACT Effective and efficient surveillance systems are key for preventing arthropod-borne diseases. We examined the capacity of Florida mosquito control districts (both state-approved and open programs, n = 90; 48.9% response rate). Questions centered on budgets, staffing levels, equipment, vector control measures, and staff perceptions of own agency's capacity to implement routine surveillance and vector control activities. Bivariate analyses indicate that districts with relatively large budgets have advanced capacities regarding staffing levels, employee specialties, mosquito control equipment, conduct routine surveillance and vector control yet they serve only a small proportion of the population. Independent tax districts' average annual budgets were 9 times higher than Board of County Commissioners programs in fiscal year 2017–18. Most respondents indicated that staff is appropriately trained, and has timely access to information and needed equipment for mosquito surveillance and control. Slightly more than half of respondents feel they are understaffed. Perceived understaffing may compromise mosquito surveillance and control efforts in some districts.

scholarly journals Control Measures on Groundwater Pollution through Leakages of Underground Storage Tanks of Filling Stations in Nigeria

2020 ◽  
pp. 98-105
Author(s):  
Oluwaseun E. Odipe ◽  
Henry O. Sawyerr ◽  
Solomon O. Adewoye
Keyword(s):  
Groundwater Pollution ◽  
Developed Countries ◽  
The United States ◽  
Control Measures ◽  
Underground Storage ◽  
Storage Tanks ◽  
Underground Storage Tanks ◽  
Global Issue ◽  
Leaking Underground Storage Tanks ◽  
And Control

Background: Groundwater pollution from leakages of Underground Storage Tanks is a global issue and has been significantly controlled and maintained by many developed countries in the last 30 years. The knowledge and practices used in containing this environmental issue can also be applied locally in Nigeria. Methods: This paper reviewed the environmental policies and strategies put in place by the United States of America and the statutory regulations in Nigeria to identify the possible causes of pollution from leaking underground storage tanks within the country in order to recommend applicable preventive and control measures. Results: Findings showed there are lots of regulations and laws to protect environmental resources in Nigeria which has led to establishment of different ministries, departments and agencies of government for implementation yet, a number of shortcomings can be traced to its inability to efficiently control leaking underground storage tanks in filling stations nationwide. Conclusion: However, necessary recommendations were made which could be applied by implementing minor preventive measures and procedures that will significantly curb this menace as achieved in other developed nations of the world.

scholarly journals Which policies most effectively reduce SARS-CoV-2 transmission in schools?

2020 ◽  
Author(s):  
Anna Bershteyn ◽  
Hae-Young Kim ◽  
Jessica McGillen ◽  
R. Scott Braithwaite
Keyword(s):  
New York ◽  
Infection Control ◽  
Primary Source ◽  
The United States ◽  
Control Measures ◽  
Infection Control Measures ◽  
Symptom Screening ◽  
Local Case ◽  
Transmission Reduction ◽  
The Impact

AbstractIntroductionNew York City (NYC) has the largest public school system in the United States (US). During the SARS-CoV-2 pandemic, NYC was the first major US city to open schools for in-person learning in the 2020-2021 academic year. Several policies were implemented to reduce the risk of in-school transmission, including infection control measures (facemasks, physical distancing, enhanced indoor ventilation, cohorting of small groups, and hand hygiene), option of all-remote instruction, alternative options for how class schedules would rotate in-person and remote instruction, daily symptom screening, and testing 10-20% of students and staff weekly or monthly depending on local case rates. We sought to determine which of these policies had the greatest impact on reducing the risk of in-school transmission.MethodsWe evaluated the impact of each policy by referring to global benchmarks for the secondary attack rate (SAR) of SARS-CoV-2 in school settings and by simulating the potential for transmission in NYC’s rotating cohort schedules, in which teachers could act as “bridges” across rotating cohorts. We estimated the impact of (1) infection control measures, (2) providing an option of all-remote instruction, (3) choice of class scheduling for in-person learners, (4) daily symptom screening, (5) testing to curtail transmission, and (6) testing to identify school outbreaks. Each policy was assessed independently of other policies, with the exception of symptom screening and random testing, which were assessed both independently and jointly.ResultsAmong the policies analyzed, the greatest transmission reduction was associated with the infection control measures, followed by small class cohorts with an option for all-remote instruction, symptom screening, and finally randomly testing 10-20% of school attendees. Assuming adult staff are the primary source of within-school SARS-CoV-2 transmission, weekly testing of staff could be at least as effective as symptom screening, and potentially more so if testing days occur in the beginning of the workweek with results available by the following day. A combination of daily symptom screening and testing on the first workday of each week could reduce transmission by 70%.ConclusionsAdherence to infection control is the highest priority for safe school re-opening. Further transmission reduction can be achieved through small rotating class cohorts with an option for remote learning, widespread testing at the beginning of the work week, and daily symptom screening and self-isolation. Randomly testing 10-20% of attendees weekly or monthly does not meaningfully curtail transmission and may not detect outbreaks before they have spread beyond a handful of individuals. School systems considering re-opening during the SARS-CoV-2 pandemic or similarly virulent respiratory disease outbreaks should consider these relative impacts when setting policy priorities.

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