Agricultural area increases the infection risk of free ranging birds to St. Louis encephalitis and West Nile viruses (Flavivirus)

Anthropogenic changes affect biological communities of host and vectors driving arbovirus activity. In general, urban and agricultural ecosystems harbor less avian and mosquito diversity than native ecosystems and are dominated by few species. Human activities have led to the emergence / re-emergence of different infectious pathogens particularly arboviruses representing a threat to both public health and biodiversity. Saint Louis encephalitis (SLEV) and West Nile viruses (WNV) are transmitted by Culex spp. mosquitoes as main vectors and several bird species as hosts. With the aim to study the exposure of free-ranging bird communities to SLEV and WNV in Pampean agroecosystems as well as to evaluate the environmental/ biological factors potentially associated we collected and bleed free ranging birds in 12 sites. Serum samples were analyzed by Plaque Reduction Neutralization Test (PRNT) for both viruses. Generalized Linear Mixed Models (GLMM) were performed to analyze the association between environmental / biological variables from each sampled site and avian exposition. A total of 1019 birds were sampled during 2017 - 2019. Overall, we found SLEV NTAb in 60 out of 1019 samples (5.8%) while WNV seroprevalence was 2.1% (21/1019). SLEV and WNV seroprevalence were different among the sampled sites. Agricultural area was positively associated with the SLEV-WNV infection risk for an avian host. Forested area also had a strong association but in a negative way. Our results suggest that open agricultural area increase the infection risk of free ranging birds to SLEV and WNV while forested area diminishes the infection risk maybe through a dilution effect of vector and host communities.

Download Full-text

Integrating Spatiotemporal Epidemiology, Eco-Phylogenetics, and Distributional Ecology to Assess West Nile Disease Risk in Horses

Viruses ◽

10.3390/v13091811 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1811

Author(s):

John M. Humphreys ◽

Angela M. Pelzel-McCluskey ◽

Lee W. Cohnstaedt ◽

Bethany L. McGregor ◽

Kathryn A. Hanley ◽

...

Keyword(s):

Community Dynamics ◽

Disease Risk ◽

Bird Species ◽

Integrated Approach ◽

The United States ◽

Host Community ◽

Avian Host ◽

West Nile ◽

Phylogenetic Structure ◽

Vaccination Programs

Mosquito-borne West Nile virus (WNV) is the causative agent of West Nile disease in humans, horses, and some bird species. Since the initial introduction of WNV to the United States (US), approximately 30,000 horses have been impacted by West Nile neurologic disease and hundreds of additional horses are infected each year. Research describing the drivers of West Nile disease in horses is greatly needed to better anticipate the spatial and temporal extent of disease risk, improve disease surveillance, and alleviate future economic impacts to the equine industry and private horse owners. To help meet this need, we integrated techniques from spatiotemporal epidemiology, eco-phylogenetics, and distributional ecology to assess West Nile disease risk in horses throughout the contiguous US. Our integrated approach considered horse abundance and virus exposure, vector and host distributions, and a variety of extrinsic climatic, socio-economic, and environmental risk factors. Birds are WNV reservoir hosts, and therefore we quantified avian host community dynamics across the continental US to show intra-annual variability in host phylogenetic structure and demonstrate host phylodiversity as a mechanism for virus amplification in time and virus dilution in space. We identified drought as a potential amplifier of virus transmission and demonstrated the importance of accounting for spatial non-stationarity when quantifying interaction between disease risk and meteorological influences such as temperature and precipitation. Our results delineated the timing and location of several areas at high risk of West Nile disease and can be used to prioritize vaccination programs and optimize virus surveillance and monitoring.

Download Full-text

Bactericidal activity of avian complement: a contribution to understand avian-host tropism of Lyme borreliae

Parasites & Vectors ◽

10.1186/s13071-021-04959-0 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Valerie Sürth ◽

Isabel Lopes de Carvalho ◽

Maria Sofia Núncio ◽

Ana Cláudia Norte ◽

Peter Kraiczy

Keyword(s):

Molecular Mechanisms ◽

Bird Species ◽

Parus Major ◽

Columba Livia ◽

Sensu Stricto ◽

Avian Host ◽

Serum Samples ◽

Host Tropism ◽

Tick Infection

AbstractComplement has been considered as an important factor impacting the host–pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete’s ecology. Birds are known to be important hosts for ticks and in the maintenance of borreliae. Recent field surveys and laboratory transmission studies indicated that certain avian species act as reservoir hosts for different Borrelia species. Nevertheless, our current understanding of the molecular mechanisms determining host tropism of Borrelia is still in its fledgling stage. Concerning the role of complement in avian-host tropism, only a few bird species and Borrelia species have been analysed so far. Here, we performed in vitro serum bactericidal assays with serum samples collected from four bird species including the European robin Erithacus rubecula, the great tit Parus major, the Eurasian blackbird Turdus merula, and the racing pigeon Columba livia, as well as four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi sensu stricto). From July to September 2019, juvenile wild birds were caught using mist nets in Portugal. Racing pigeons were sampled in a loft in October 2019. Independent of the bird species analysed, all Borrelia species displayed an intermediate serum-resistant or serum-resistant phenotype except for B. afzelii challenged with serum from blackbirds. This genospecies was efficiently killed by avian complement, suggesting that blackbirds served as dead-end hosts for B. afzelii. In summary, these findings suggest that complement contributes in the avian–spirochete–tick infection cycle and in Borrelia-host tropism.

Download Full-text

Absence of Mycoplasma spp. in nightingales (Luscinia megarhynchos) and blue (Cyanistes caeruleus) and great tits (Parus major) in Germany and its potential implication for evolutionary studies in birds

European Journal of Wildlife Research ◽

10.1007/s10344-021-01554-7 ◽

2021 ◽

Vol 68 (1) ◽

Author(s):

Luisa Fischer ◽

Franca Möller Palau-Ribes ◽

Silke Kipper ◽

Michael Weiss ◽

Conny Landgraf ◽

...

Keyword(s):

Respiratory Tract ◽

Bird Species ◽

Respiratory Pathogen ◽

Economic Losses ◽

Rrna Gene ◽

Upper Respiratory Tract ◽

Healthy Individuals ◽

Cyanistes Caeruleus ◽

Potential Implication ◽

Free Ranging

AbstractMycoplasma spp. are important pathogens in poultry and cause high economic losses for poultry industry worldwide. In other bird species (e.g. white storks, birds of prey, and several waterfowl species), Mycoplasma spp. are regularly found in healthy individuals, hence, considered apathogenic or part of the microbiota of the upper respiratory tract. However, as Mycoplasma spp. are absent in healthy individuals of some wild bird species, they might play a role as respiratory pathogen in these bird species, e.g. Mycoplasma gallisepticum in house finches. The knowledge on the occurrence of Mycoplasma spp. in wild birds is limited. To evaluate the relevance of Mycoplasma spp. in free-ranging nightingales and tits, 172 wild caught birds were screened for the presence of mycoplasmas. The birds were sampled via choanal swabs and examined via molecular methods (n = 172) and, when possible, via culture (n = 142). The Mycoplasma sp. was determined by sequencing the 16S rRNA gene and 16S-23S Intergenic Transcribed Spacer Region. All birds were tested negative for mycoplasmas via PCR and/or mycoplasmal culture. Hence, free-ranging nightingales and tits do not show any mycoplasma in their microbial flora of the respiratory tract. Therefore, these songbird species may suffer from clinical mycoplasmosis when being infected. We hypothesize that birds relying on their vocal ability for reproduction have excluded mycoplasmas from their respiratory flora compared to other bird species.

Download Full-text

Foodborne Snow Mountain Agent Gastroenteritis in a School Cafeteria

PEDIATRICS ◽

10.1542/peds.79.4.559 ◽

1987 ◽

Vol 79 (4) ◽

pp. 559-563

Author(s):

Charles Guest ◽

Kenneth C. Spitalny ◽

H. Paul Madore ◽

Katherine Pray ◽

Raphael Dolin ◽

...

Keyword(s):

Relative Risk ◽

Strong Association ◽

Case Definition ◽

Enzyme Linked Immunosorbent Assay ◽

Fisher Exact Test ◽

Confidence Limits ◽

Serum Samples ◽

Exact Test ◽

Relative Risks ◽

The Mean

In 1984, an outbreak of gastroenteritis occurred at a school with 1,860 students in Brooklyn, NY. In a single-stage cluster sample of 375 students, 129 (34%) had illnesses that met our case definition of vomiting or diarrhea. The mean incubation period was 26 hours, and the mean illness duration was 24 hours. All case students had eaten in the cafeteria on at least one day between Nov 13 and 16, compared with 174/214 (81%) noncase students (P = 10-8, Fisher exact test). Foods implicated were french fries (relative risk 1.7, 95% confidence limits 1.4, 2.0) and hamburgers (relative risk 1.6, 95%, confidence limits 1.2, 2.1). Two cafeteria employees had served those foods while affected by diarrhea. By a recently developed blocking enzyme-linked immunosorbent assay, six of 11 (55%) case students showed fourfold antibody increases between acute-and convalescent-phase serum samples for Snow Mountain agent, a Norwalk-like virus, compared with one of ten (10%) noncase students (P = .04, Fisher exact test). We strongly suspect, but cannot document conclusively, that the Snow Mountain agent was spread to students on a vector of hot foods contaminated by ill food handlers. Implicated foods conferred low relative risks and could only have accounted for 74% of cases of illness. The strong association between cafeteria exposure and illness, therefore, suggests that additional modes of spread occurred.

Download Full-text

West Nile Virus and Related Flavivirus in European Wild Boar (Sus scrofa), Latium Region, Italy: A Retrospective Study

Animals ◽

10.3390/ani10030494 ◽

2020 ◽

Vol 10 (3) ◽

pp. 494

Author(s):

Angela Petruccelli ◽

Tiziana Zottola ◽

Gianmarco Ferrara ◽

Valentina Iovane ◽

Cristina Di Russo ◽

...

Keyword(s):

West Nile Virus ◽

Wild Boar ◽

Specific Antibody ◽

Central Italy ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Serum Samples ◽

West Nile ◽

Wild Boars ◽

European Wild Boar

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.

Download Full-text

Parasitological survey on birds at some selected brazilian zoos

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612015005 ◽

2015 ◽

Vol 24 (1) ◽

pp. 87-91 ◽

Cited By ~ 1

Author(s):

Paulo Gonzalez Hofstatter ◽

Ana Maria Aparecida Guaraldo

Keyword(s):

Bird Species ◽

Sao Paulo ◽

Parasite Fauna ◽

São Paulo ◽

Fecal Samples ◽

Parasitological Survey ◽

The Subject ◽

Coccidian Species ◽

Free Ranging

A parasitological survey was conducted at some zoos in the states of São Paulo and Paraná, Brazil, from 2009 to 2011. Several groups of birds were surveyed for fecal samples, but the most important was Psittacidae. Among the parasites, Eimeria (coccidian) and Capillaria, Ascaridia and Heterakis (nematodes) were observed in almost one third of the samples. Presence of a rich parasite fauna associated with captive birds seems to be an effect of captivity, since data on free-ranging birds indicate few or virtually no parasites at all. The discovery of new coccidian species during this survey reveals the need of more research on the subject as even well-known bird species have unknown parasites, but caution must be exercised in order to avoid descriptions of pseudoparasites.

Download Full-text

Bird Species Potentially Involved in Introduction, Amplification, And Spread of West Nile Virus in A Mediterranean Wetland, The Camargue (Southern France)

Vector-Borne and Zoonotic Diseases ◽

10.1089/vbz.2006.0543 ◽

2007 ◽

Vol 7 (1) ◽

pp. 15-33 ◽

Cited By ~ 31

Author(s):

E. Jourdain ◽

Y. Toussaint ◽

A. Leblond ◽

D.J. Bicout ◽

P. Sabatier ◽

...

Keyword(s):

West Nile Virus ◽

Bird Species ◽

West Nile ◽

Southern France

Download Full-text

Rapid Detection of Serum Antibody by Dual-Path Platform VetTB Assay in White-Tailed Deer Infected with Mycobacterium bovis

Clinical and Vaccine Immunology ◽

10.1128/cvi.00120-13 ◽

2013 ◽

Vol 20 (6) ◽

pp. 907-911 ◽

Cited By ~ 18

Author(s):

Konstantin P. Lyashchenko ◽

Rena Greenwald ◽

Javan Esfandiari ◽

Daniel J. O'Brien ◽

Stephen M. Schmitt ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Mycobacterium Bovis ◽

Skin Testing ◽

Serum Antibody ◽

Antibody Responses ◽

Antibody Detection ◽

Serum Samples ◽

Content Type ◽

In The Wild ◽

Free Ranging

ABSTRACTBovine tuberculosis (TB) in cervids remains a significant problem affecting farmed herds and wild populations. Traditional skin testing has serious limitations in certain species, whereas emerging serological assays showed promising diagnostic performance. The recently developed immunochromatographic dual-path platform (DPP) VetTB assay has two antigen bands, T1 (MPB83 protein) and T2 (CFP10/ESAT-6 fusion protein), for antibody detection. We evaluated the diagnostic accuracy of this test by using serum samples collected from groups of white-tailed deer experimentally inoculated withMycobacterium bovis,M. aviumsubsp.paratuberculosis, orM. bovisBCG Pasteur. In addition, we used serum samples from farmed white-tailed deer in herds with no history of TB, as well as from free-ranging white-tailed deer culled during field surveillance studies performed in Michigan known to have bovine TB in the wild deer population. The DPP VetTB assay detected antibody responses in 58.1% of experimentally infected animals within 8 to 16 weeks postinoculation and in 71.9% of naturally infected deer, resulting in an estimated test sensitivity of 65.1% and a specificity of 97.8%. The higher seroreactivity found in deer with naturally acquiredM. bovisinfection was associated with an increased frequency of antibody responses to the ESAT-6 and CFP10 proteins, resulting in a greater contribution of these antigens, in addition to MPB83, to the detection of seropositive animals, compared with experimentalM. bovisinfection. Deer experimentally inoculated with eitherM. aviumsubsp.paratuberculosisorM. bovisBCG Pasteur did not produce cross-reactive antibodies that could be detected by the DPP VetTB assay. The present findings demonstrate the relatively high diagnostic accuracy of the DPP VetTB test for white-tailed deer, especially in the detection of naturally infected animals.

Download Full-text

Detection of Specific Antibodies against Toscana Virus among Blood Donors in Northeastern Italy and Correlation with Sand Fly Abundance in 2014

Microorganisms ◽

10.3390/microorganisms8020145 ◽

2020 ◽

Vol 8 (2) ◽

pp. 145 ◽

Cited By ~ 1

Author(s):

Silvia Morini ◽

Mattia Calzolari ◽

Giada Rossini ◽

Nadia Pascarelli ◽

Andrea Porcellini ◽

...

Keyword(s):

Blood Donors ◽

Strong Association ◽

Immunofluorescence Assay ◽

Sand Fly ◽

Seroprevalence Rate ◽

Toscana Virus ◽

Serum Samples ◽

Explanatory Variables ◽

Northeastern Italy ◽

Microneutralization Test

Toscana virus (TOSV) is a Phlebovirus transmitted by phlebotomine sand flies and is an important etiological agent of summer meningitis in the Mediterranean basin. Since TOSV infection is often asymptomatic, we evaluated the seroprevalence in blood donors (BDs) in the Bologna and Ferrara provinces (Northeastern Italy)—the areas with the highest and lowest numbers of TOSV neuroinvasive cases in the region, respectively. A total of 1208 serum samples from BDs were collected in April–June 2014 and evaluated for the presence of specific TOSV-IgG by ELISA. The IgG-reactive samples were confirmed by indirect immunofluorescence assay (IIF) and by microneutralization test (MN). Serum samples were defined as positive for anti-TOSV IgG when reactive by ELISA and by at least one second-level test; TOSV seroprevalence was 6.8% in the Bologna province, while no circulation of TOSV was detected in the Ferrara province. Sand fly abundance in 2014 was also estimated by a geographic information system using a generalized linear model applied to a series of explanatory variables. TOSV seroprevalence rate was strongly associated with the sand fly abundance index in each municipality, pointing out the strong association between sand fly abundance and human exposure to TOSV.

Download Full-text

On the Fly: Interactions Between Birds, Mosquitoes, and Environment That Have Molded West Nile Virus Genomic Structure Over Two Decades

Journal of Medical Entomology ◽

10.1093/jme/tjz112 ◽

2019 ◽

Vol 56 (6) ◽

pp. 1467-1474 ◽

Cited By ~ 3

Author(s):

Nisha K Duggal ◽

Kate E Langwig ◽

Gregory D Ebel ◽

Aaron C Brault

Keyword(s):

West Nile Virus ◽

Vector Competence ◽

Genomic Structure ◽

Inverse Correlation ◽

Purifying Selection ◽

Relative Effect ◽

Avian Host ◽

West Nile ◽

House Sparrows ◽

Host Competence

Abstract West Nile virus (WNV) was first identified in North America almost 20 yr ago. In that time, WNV has crossed the continent and established enzootic transmission cycles, resulting in intermittent outbreaks of human disease that have largely been linked with climatic variables and waning avian seroprevalence. During the transcontinental dissemination of WNV, the original genotype has been displaced by two principal extant genotypes which contain an envelope mutation that has been associated with enhanced vector competence by Culex pipiens L. (Diptera: Culicidae) and Culex tarsalis Coquillett vectors. Analyses of retrospective avian host competence data generated using the founding NY99 genotype strain have demonstrated a steady reduction in viremias of house sparrows over time. Reciprocally, the current genotype strains WN02 and SW03 have demonstrated an inverse correlation between house sparrow viremia magnitude and the time since isolation. These data collectively indicate that WNV has evolved for increased avian viremia while house sparrows have evolved resistance to the virus such that the relative host competence has remained constant. Intrahost analyses of WNV evolution demonstrate that selection pressures are avian species-specific and purifying selection is greater in individual birds compared with individual mosquitoes, suggesting that the avian adaptive and/or innate immune response may impose a selection pressure on WNV. Phylogenomic, experimental evolutionary systems, and models that link viral evolution with climate, host, and vector competence studies will be needed to identify the relative effect of different selective and stochastic mechanisms on viral phenotypes and the capacity of newly evolved WNV genotypes for transmission in continuously changing landscapes.

Download Full-text