scholarly journals 4102 Assessment of ivermectin-treated backyard chickens as a novel urban West Nile virus prevention strategy

2020 ◽  
Vol 4 (s1) ◽  
pp. 123-124
Author(s):  
Karen Holcomb ◽  
Chilinh Nguyen ◽  
Brian D. Foy ◽  
Christopher M. Barker
Keyword(s):  
West Nile Virus ◽  
Control Strategy ◽  
Untreated Control ◽  
Mosquito Control ◽  
Infection Prevalence ◽  
West Nile ◽  
Mosquito Abundance ◽  
Study Results ◽  
Parity Rate ◽  
Backyard Chickens

OBJECTIVES/GOALS: We conducted a randomized field trail to evaluate the efficacy and safety of a novel vector control strategy that involves treating urban backyard chickens with ivermectin (IVM), a widely used antiparasitic and mosquitocial drug. The goal was to reduce vector mosquito populations and West Nile virus (WNV) transmission. METHODS/STUDY POPULATION: We placed eight flocks—four treated and four untreated control—of six Lohmann brown chickens (16 month-old) each in backyard coops across Davis, CA and administered IVM in feed daily at treated coops (200 mg IVM/kg feed) for eleven weeks. We monitored entomological indices weekly (i.e. mosquito abundance, WNV infection prevalence, and parity rate) in Culex mosquito populations near (10 m) and far (150 m) from each coop location for the peak WNV transmission season (Jul-Sep 2019). We also monitored serum IVM levels in treated chickens and tested for WNV antibodies in all chickens throughout the study. RESULTS/ANTICIPATED RESULTS: Since IVM impacts only mosquitoes that live long enough to take a bloodmeal from a treated chicken, we do not expect to find a marked difference in adult Culex abundance between the two treatment arms, but we expect to find a reduction in WNV infection prevalence and a shift in female mosquito age structure towards younger, uninfected individuals at treated coops. We also anticipate seroconversions in treated chickens to occur at lower rates versus untreated control chickens indicating a reduction in WNV transmission intensity at treated coops. We observed no negative health outcomes from the long-term ingestion of IVM by study chickens. A pathological investigation is underway to compare histological findings between treated and untreated chickens. DISCUSSION/SIGNIFICANCE OF IMPACT: IVM provides the potential for targeted mosquito control. Reduced WNV transmission dynamics here is a stepping stone to a commercial WNV control strategy; IVM-treated feed for wild birds for homeowners’ use to combat WNV transmission in their neighborhoods.

scholarly journals Emergence of West Nile virus infections in humans in Turkey, 2010 to 2011

2012 ◽  
Vol 17 (21) ◽  
Author(s):  
H Kalaycioglu ◽  
G Korukluoglu ◽  
A Ozkul ◽  
O Oncul ◽  
S Tosun ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Mosquito Control ◽  
Epidemiological Studies ◽  
Control Measures ◽  
Lower Activity ◽  
Virus Infections ◽  
West Nile ◽  
Notifiable Diseases ◽  
Routine Surveillance

In 2010, 47 human cases of West Nile virus (WNV) infection, including 12 laboratory-confirmed and 35 probable cases, were identified in Turkey. These were the first cases detected during routine surveillance. The patients were from 15 provinces, mainly located in the western part of the country. Incidence was 0.19/100,000 with a maximum of 1.39 in Sakarya province. Forty of the total 47 cases showed neuroinvasive manifestation. Median age was 58 years with a range of four to 86. Ten of the patients died. Enhanced surveillance in humans and animals and mosquito control measures were implemented. The WNV infections were included in the national notifiable diseases list as of April 2011. In 2011, three probable and two confirmed cases of WNV infection were diagnosed in provinces where infections had been detected in the previous year, supporting a lower activity than 2010. However, detection of WNV infections in humans in 2010 and 2011 consecutively, may indicate that WNV has become endemic in the western part of Turkey. Field epidemiological studies were undertaken to understand more about the nature of infection in Turkey.

scholarly journals Key Factors Influencing the Incidence of West Nile Virus in Burleigh County, North Dakota

2018 ◽  
Vol 15 (9) ◽  
pp. 1928 ◽  
Author(s):  
Hiroko Mori ◽  
Joshua Wu ◽  
Motomu Ibaraki ◽  
Franklin Schwartz
Keyword(s):  
West Nile Virus ◽  
North Dakota ◽  
Transmission Rate ◽  
Virus Transmission ◽  
Correlation Coefficients ◽  
West Nile ◽  
Mosquito Abundance ◽  
River Flooding ◽  
Disease Case ◽  
The City

The city of Bismarck, North Dakota has one of the highest numbers of West Nile Virus (WNV) cases per population in the U.S. Although the city conducts extensive mosquito surveillance, the mosquito abundance alone may not fully explain the occurrence of WNV. Here, we developed models to predict mosquito abundance and the number of WNV cases, independently, by statistically analyzing the most important climate and virus transmission factors. An analysis with the mosquito model indicated that the mosquito numbers increase during a warm and humid summer or after a severely cold winter. In addition, river flooding decreased the mosquito numbers. The number of WNV cases was best predicted by including the virus transmission rate, the mosquito numbers, and the mosquito feeding pattern. This virus transmission rate is a function of temperature and increases significantly above 20 °C. The correlation coefficients (r) were 0.910 with the mosquito-population model and 0.620 with the disease case model. Our findings confirmed the conclusions of other work on the importance of climatic variables in controlling the mosquito numbers and contributed new insights into disease dynamics, especially in relation to extreme flooding. It also suggested a new prevention strategy of initiating insecticides not only based on mosquito numbers but also 10-day forecasts of unusually hot weather.

scholarly journals First Evidence of West Nile Virus Overwintering in Mosquitoes in Germany

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2463
Author(s):  
Helge Kampen ◽  
Birke Andrea Tews ◽  
Doreen Werner
Keyword(s):  
West Nile Virus ◽  
Culex Pipiens ◽  
Dna Analysis ◽  
Public Health Issue ◽  
Federal State ◽  
Infection Prevalence ◽  
Acid Extraction ◽  
Coding Region ◽  
West Nile ◽  
Northeastern Germany

Mosquitoes collected from mid-December 2020 to early March 2021 from hibernacula in northeastern Germany, a region of West Nile virus (WNV) activity since 2018, were examined for WNV-RNA. Among the 6101 mosquitoes tested in 722 pools of up to 12 specimens, one pool of 10 Culex pipiens complex mosquitoes collected in early March 2021 in the cellar of a medieval castle in Rosslau, federal state of Saxony-Anhalt, tested positive. Subsequent mosquito DNA analysis produced Culex pipiens biotype pipiens. The pool homogenate remaining after nucleic acid extraction failed to grow the virus on Vero and C6/36 cells. Sequencing of the viral NS2B-NS3 coding region, however, demonstrated high homology with virus strains previously collected in Germany, e.g., from humans, birds, and mosquitoes, which have been designated the East German WNV clade. The finding confirms the expectation that WNV can overwinter in mosquitoes in Germany, facilitating an early start to the natural transmission season in the subsequent year. On the other hand, the calculated low infection prevalence of 0.016–0.20%, depending on whether one or twelve of the mosquitoes in the positive pool was/were infected, indicates a slow epidemic progress and mirrors the still-hypoendemic situation in Germany. In any case, local overwintering of the virus in mosquitoes suggests its long-term persistence and an enduring public health issue.

scholarly journals A molecular surveillance-guided vector control response to concurrent dengue and West Nile virus outbreaks in a COVID-19 hotspot of Florida

2021 ◽  
Author(s):  
Heather Coatsworth ◽  
Cat Lippi ◽  
Chalmers Vasquez ◽  
Jasmine B Ayers ◽  
Caroline J. Stephenson ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Dengue Virus ◽  
Molecular Diagnostic ◽  
Infection Prevalence ◽  
Dade County ◽  
Outbreak Response ◽  
West Nile ◽  
Local Index ◽  
Denv Serotypes ◽  
Virus Serotype

Simultaneous dengue virus (DENV) and West Nile virus (WNV) outbreaks in Florida, USA, in 2020 resulted in 71 dengue virus serotype 1 and 86 WNV human cases. Our outbreak response leveraged a molecular diagnostic screen of mosquito populations for DENV and WNV in Miami-Dade County to quickly employ targeted mosquito abatement efforts. We detected DENV serotypes 2 and 4 in mosquito pools, highlighting the silent circulation of diverse dengue serotypes in mosquitoes. Additionally, we found WNV-positive mosquito pools in areas with no historical reports of WNV transmission. These findings demonstrate the importance of proactive, strategic arbovirus surveillance in mosquito populations to prevent and control outbreaks, particularly when other illnesses (e.g., COVID-19), which present with similar symptoms are circulating concurrently. Growing evidence for substantial infection prevalence of dengue in competent mosquito vectors in the absence of local index cases suggests a higher level of dengue endemicity in Florida than previously thought.

scholarly journals West Nile virus in humans, Greece, 2018: the largest seasonal number of cases, 9 years after its emergence in the country

2020 ◽  
Vol 25 (32) ◽  
Author(s):  
Danai Pervanidou ◽  
Annita Vakali ◽  
Theano Georgakopoulou ◽  
Takis Panagiotopoulos ◽  
Eleni Patsoula ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Geographical Distribution ◽  
Urban Areas ◽  
Mosquito Control ◽  
Daily Basis ◽  
West Nile ◽  
Public Health Organization ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Health Organization

Background Human cases of West Nile virus (WNV) infection are recorded since 2010 in Greece, with seasonal outbreaks occurring almost annually. Enhanced surveillance has been implemented since 2010, to promptly characterise cases’ temporal and geographical distribution and inform authorities for implementation of appropriate measures (mosquito control, health education, blood safety). Aim We describe the epidemiology of WNV human infections in Greece focusing on the 2018 season. Methods The National Public Health Organization advised physicians to test all suspect WNV infection cases and refer samples to reference laboratories. Laboratories notified diagnosed cases on a daily basis. Treating physicians, patients, and infected blood donors were interviewed within 48 hours after diagnosis and the probable infection location was identified. Hospitalised cases were followed up until discharge. Results A total of 317 autochthonous WNV infection cases were diagnosed in 2018. Among them, 243 cases had neuroinvasive disease (WNND), representing a 23% increase of WNND cases compared with 2010, the previous most intense season. There were 51 deaths. Cases started occurring from week 22, earlier than usual. Both rural and urban areas were affected, with 86 (26% of the total) municipalities belonging to seven (54% of the total) regions recording cases. Two major epicentres were identified in Attica and Central Macedonia regions. Conclusions The largest number of human cases of WNV infection ever recorded in Greece occurred in 2018, with a wide geographical distribution, suggesting intense virus circulation. Enhanced surveillance is vital for the early detection of human cases and the prompt implementation of response measures.

scholarly journals Public Perceptions on Non-Pharmaceutical Interventions for West Nile Virus Infections: A Survey from an Endemic Area in Northern Italy

2021 ◽  
Vol 6 (3) ◽  
pp. 116
Author(s):  
Matteo Riccò ◽  
Simona Peruzzi ◽  
Federica Balzarini
Keyword(s):  
West Nile Virus ◽  
Mosquito Control ◽  
Severe Disease ◽  
Health Belief ◽  
Binary Logistic Regression ◽  
Virus Infections ◽  
West Nile ◽  
Po River ◽  
Control Programs ◽  
Preventive Practices

During the last decade, cases of West Nile Virus (WNV) have occurred in the Emilia Romagna Region (ERR). Even though the notification rates remain relatively low, ranging from 0.06 to 1.83 cases/100,000 inhabitants, the persistent pathogen’s circulation in settings characterized by favorable environmental characteristics suggests that WNV is becoming endemic to the Po River Valley. This study assesses knowledge, attitudes, and preventive practices toward WNV prevention among residents from 10 high-risk municipalities from the provinces of Parma and Reggio Emilia (total population: 82,317 inhabitants, census 2020). A web-based survey, based on the health belief model, was performed during the month of January 2021, with a convenience sampling of 469 participants from a series of closed discussion groups on social media (i.e., 2.1% of the potential responders). A total of 243 participants knew the meaning of WNV: Of them, 61.3% were aware of previous WNV infections in ERR, 76.5% acknowledged WNV infection as a severe one, but only 31.3% expressed any worry about WNV. Our results irregularly report preventive practices, either collective (e.g., draining standing water from items and the environment, 50.7%; spraying pesticides around the home, 33.0%) or individual (e.g., use of skin repellants when going outdoors, 42.6%). In a multivariate analysis, performed through binary logistic regression, participants reporting any worry towards WNV were more likely to characterize WNV as a severe disease (adjusted odds ratio [aOR] = 20.288, 95% confidence interval [CI] = 5.083–80.972). On the contrary, respondents supporting community mosquito control programs were more likely among people working with animals/livestock (aOR = 13.948, 95%CI = 2.793–69.653), and supporting tax exemptions for mosquito control programs (aOR = 4.069, 95%CI 2.098–7.893). In conclusion, our results suggest that future interventions promoting WNV prevention among residents in ERR should focus on perceptions of vulnerability to WNV, emphasizing the benefits of personal protective behaviors.

Building a climate service to support an Εarly Warning System for the West Nile Virus disease in Greece

2020 ◽  
Author(s):  
Eleni Katragkou ◽  
Maria Chara Karypidou ◽  
Stergios Kartsios ◽  
Sandra Gewehr ◽  
Spiros Mourelatos
Keyword(s):  
West Nile Virus ◽  
Early Warning ◽  
Early Warning System ◽  
Mosquito Control ◽  
Virus Disease ◽  
Empirical Relationship ◽  
Warning System ◽  
West Nile ◽  
Study Region ◽  
Climate Service

<p>According to the National Public Health Organization in Greece, cases of West Nile Virus (WNV) infection in humans and animals have been recorded in various areas over Greece during the years 2010-2014 and 2017-2019 (https://eody.gov.gr). In this work we present a climate service which supports an Early Warning System (EWS) for the mosquito-borne WNV disease, operated for the first time over the Region of Central Macedonia in Greece. The EWS is based on a platform fed by time-dependent data (climate information and mosquito population data (Culex sp.)) and time invariant data (topography, density of mosquito breeding sites taken from field campaigns and distance to water-related land cover categories). The climate data are produced on a daily basis by the WRF-AUTH-MC weather forecast model over a 2x2 Km grid covering the Region of Central Macedonia, which operates from April to October (mosquito circulation period). Mosquito samples are collected every 2 weeks by the company ECODEVELOPMENT, using CO<sub>2</sub> mosquito traps. The mosquito data along with the climatic and static environmental information are utilized within a Generalized Linear Model (GLM). Based on an empirical relationship derived from the GLM, the overall environmental suitability for the Culex mosquito is assessed over the study region. The work is performed in the framework of the German-Greek bilateral project “Establishment of an Early Warning System for mosquito borne diseases” (http://www.wnvalert.eu/), which is focusing on improved measures on proactive mosquito control and disease prevention activities.</p>

scholarly journals The Potential of West Nile Virus Transmission Regarding the Environmental Factors Using Geographic Information System (GIS), West Azerbaijan Prov¬ince, Iran

2019 ◽  
Author(s):  
Mojtaba Amini ◽  
Ahmad Ali Hanafi-Bojd ◽  
Sayyad Asghari ◽  
Ali Reza Chavshin
Keyword(s):  
Information System ◽  
West Nile Virus ◽  
High Risk ◽  
Environmental Factors ◽  
Mosquito Species ◽  
West Nile ◽  
Study Results ◽  
West Nile Virus Transmission ◽  
Risk Areas ◽  
West Azerbaijan

Background: West Nile fever, as an expanding zoonotic disease, has been reported from different creatures involved in the disease from Iran. In addition to biological mosquito-associated factors, various elements such as their activi­ties, distribution, behavior and vectorial capacity could be affected by environmental factors. We determined the dis­tribution of West Nile virus (WNV) vectors, the environmental factors affecting WNV transmission and the high-risk areas across West Azerbaijan Province (Northwestern Iran), regarding the potential of WNV transmission using Ge­ographical Information System (GIS). Methods: Mosquitoes’ larvae and adults were collected from different habitats of the province in 2015 and identified using standard morphological keys. The data regarding the distribution of mosquitoes across the studied area were organized in ArcMap databases. Inverse Distance Weighted (IDW) interpolation analysis was conducted on the data of synoptic stations to find climatic variables in the collection sites of different mosquito species. Layers of transmis­sion-related environmental factors were categorized and weighed based on their effects on disease transmission. Results: Overall, 2813 samples of different mosquito species from different regions of the province were collected and identified. According to the GIS analysis, areas in the northeastern province, which have lower altitudes and slopes with higher temperatures and more water bodies, were found to have better condition for the activity of mos­quitoes (as high-risk areas: hot spots). Conclusion: The precision of our results was proven to be in line with previous study results that identified high-risk areas, where WNV-infected vectors were captured from these same areas.

Sign in / Sign up

Export Citation Format

Share Document