Declining Mortality in American Crow (Corvus brachyrhynchos) Following Natural West Nile Virus Infection

Reed, Lisa M.; Johansson, Michael A.; Panella, Nicholas A.; McLean, Robert G.; Creekmore, Terry E.; Puelle, Rose; Komar, Nicholas

doi:10.1637/8468-091208-resnote.1

Cited by 20 publications

(9 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Corvidae (Order Passeriformes ) are among the most susceptible avian families to WN disease [127,131], but the virus has caused death and morbidity in at least 326 species [132]. A serosurvey of American crows in 1999 in New Jersey found 5.1% seropositive for WNV [133], and 50% of wild birds tested in the epicenter (Queens, NY, USA) were seropositive [134]. Nonetheless, severe regional declines have been noted in some avian species [131] following introduction of WNV.…”

Section: Vertebratementioning

confidence: 99%

Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

Ciota

Kramer

2013

Viruses

123

View full text Add to dashboard Cite

West Nile virus (WNV; Flavivirus; Flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. Mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. The concept of vectorial capacity integrates these factors to address interactions of the virus with the arthropod host, leading to a clearer understanding of their complex interrelationships, how they affect transmission of vector-borne disease, and how they impact human health. Vertebrate factors including host competence, population dynamics, and immune status also affect transmission dynamics. The complexity of these interactions are further exacerbated by the fact that not only can divergent hosts differentially alter the virus, but the virus also can affect both vertebrate and invertebrate hosts in ways that significantly alter patterns of virus transmission. This chapter concentrates on selected components of the virus-vector-vertebrate interrelationship, focusing specifically on how interactions between vector, virus, and environment shape the patterns and intensity of WNV transmission.

show abstract

Section: Vertebratementioning

confidence: 99%

Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

Ciota

Kramer

2013

Viruses

123

View full text Add to dashboard Cite

show abstract

“…The goal of this paper is to explore the connections between land use and WNV amplification and persistence in the environment by examining spatio-temporal changes in the population dynamics of American crows (Corvus brachyrhynchos), a host species with high WNV sensitivity (Komar et al 2003). American crows are especially susceptible to WNV infection, with nearly 100% mortality in laboratory challenge experiments (Komar et al 2003) and very low to nonexistent seroprevalence in the wild (Wilcox et al 2007, but see Reed et al 2009). We build on the analysis by LaDeau et al (2007), which documented clear consequences of WNV emergence for crow and other native avian species.…”

Section: Introductionmentioning

confidence: 99%

West Nile virus impacts in American crow populations are associated with human land use and climate

LaDeau

Calder

Doran

et al. 2010

Ecological Research

View full text Add to dashboard Cite

West Nile virus (WNV) was first detected in the western hemisphere during the summer of 1999, reawakening US public awareness of the potential severity of vector-borne pathogens. Since its New World introduction, WNV has caused disease in human, avian, and mammalian communities across the continent. American crows (Corvus brachyrhynchos) are a highly susceptible WNV host and when modeled appropriately, changes in crow abundances can serve as a proxy for the spatio-temporal presence of WNV. We use the dramatic declines in abundance of this avian host to examine spatio-temporal heterogeneity in WNV intensity across the northeastern US, where WNV was first detected. Using data from the Breeding Bird Survey, we identify significant declines in crow abundance after WNV emergence that are associated with lower forest cover, more urban land use, and warmer winter temperatures. Importantly, we document continued declines as WNV was present in an area over consecutive years. Our findings support the urban-pathogen link that human WNV incidence studies have shown. For each 1% increase in urban land cover we expect an additional 5% decline in the log crow abundance beyond the decline attributed to WNV in undeveloped areas. We also demonstrate a significant relationship between above-average winter temperatures and WNVrelated declines in crow abundance. The mechanisms behind these patterns remain uncertain and hypotheses requiring further research are suggested. In particular, a strong positive relationship between urban land cover and winter temperatures may confound mechanistic understanding, especially when a temperature-sensitive vector is involved.

show abstract

“…In contrast, however, the extent to which crows are able to mount an effective immune response to WNV is unclear (Nemeth et al 2011, Staley andBonneaud 2015). Early reports documented 100% mortality of crows after experimental infection (Brault et al 2004), although reports of antibodies in field-collected crows indicated that they might have resistance in some populations (Wilcox et al 2007, Reed et al 2009). In our study, however, no crows tested positive for WNV antibodies at the time of banding, indicating no previous WNV infection at that time.…”

Section: Discussionmentioning

confidence: 99%

Low heterozygosity is associated with vector‐borne disease in crows

et al. 2018

View full text Add to dashboard Cite

Infectious diseases can have devastating impacts on wildlife populations and are of particular concern for small, inbred populations. Identifying specific pathogens that are linked to morbidity and mortality in inbred individuals is a priority for the conservation of small populations, but opportunities to examine them in the wild are rare. Here, we examined the relationship between heterozygosity and infectious disease in American crows (Corvus brachyrhynchos), a species that engages in close inbreeding, focusing on three pathogens common in Davis, California, USA: West Nile virus (WNV), Plasmodium spp. (avian malaria), and Campylobacter jejuni. We found that low heterozygosity at a panel of 33 microsatellite loci was associated with two vector-borne infectious diseases (WNV and avian malaria), but not with infection by the bacterial gut pathogen C. jejuni. Reasons for this association with vector-borne pathogens are unclear, but might include behavioral factors and immunological differences associated with inbreeding. Overall, these data are consistent with the idea that inbred individuals may be more susceptible to both novel and endemic vector-borne pathogens, underscoring the importance of protecting genetic diversity within populations and buffering small populations against infectious diseases.

show abstract

Declining Mortality in American Crow (Corvus brachyrhynchos) Following Natural West Nile Virus Infection

Cited by 20 publications

References 35 publications

Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

West Nile virus impacts in American crow populations are associated with human land use and climate

Low heterozygosity is associated with vector‐borne disease in crows

Contact Info

Product

Resources

About