Wellfleet Bay Virus carried by american goldfinch

Understanding Wellfleet Bay Virus in Wildlife

Wellfleet Bay virus (WFBV) is a relatively new virus that has been identified in wild birds, specifically gulls, in the northeastern region of the United States. This article will explore the cause, significance, species affected, distribution, transmission, clinical signs, diagnosis, treatment, management, and conclusion related to WFBV in wildlife.


Wellfleet Bay virus is a flavivirus, which is a type of virus that is transmitted by arthropods, such as ticks and mosquitoes. It was first identified in 2010 during an outbreak of avian mortality in gulls along the eastern coast of the United States. The virus is closely related to the Jamestown Canyon virus, which is another flavivirus found in North America.


Although WFBV is a newly identified virus, it is considered a potential public health concern. The virus has been shown to cause neurological symptoms in birds, and it is possible that it could also affect humans who come into contact with infected birds or mosquitoes. However, there have been no reported cases of human infection with WFBV.


Affected WFBV primarily affects gulls, particularly the herring gull and great black-backed gull. However, it has also been found in other bird species, including common eider ducks and red-throated loons.


Wellfleet Bay virus has been primarily found in the eastern coastal regions of the United States, particularly in Massachusetts and Rhode Island. The virus has been detected in several species of birds, including the black-capped chickadee, tufted titmouse, and American goldfinch, among others. However, there is still limited information on the full distribution of the virus and its potential impact on wildlife populations.

Recent studies have suggested that the virus may be spreading beyond its initial geographic range, and further research is needed to determine the extent of its distribution. In addition, the virus has also been detected in mosquitoes, indicating the potential for vector-borne transmission. As such, continued monitoring and surveillance efforts are necessary to better understand the distribution of the virus and its potential impact on both wildlife and human health.


WFBV is transmitted by mosquitoes, which serve as a vector for the virus. When a mosquito bites an infected bird, it can pick up the virus and transmit it to other birds or mammals, including humans. It is also possible that the virus could be transmitted through contact with infected bird droppings or other bodily fluids.

Clinical Signs

In birds, WFBV can cause a range of neurological symptoms, including weakness, ataxia, and tremors. Birds infected with the virus may also exhibit signs of disorientation and unusual behavior, such as flying into objects. In some cases, infected birds may die suddenly without exhibiting any symptoms.


Diagnosing WFBV in wildlife can be challenging, as the virus is not well understood and there are no commercial tests available to detect it. Diagnosis is typically made through PCR testing of bird tissue samples.


There is currently no specific treatment or vaccine for WFBV in wildlife. However, supportive care may be provided to infected birds to help alleviate their symptoms.


Currently, there is no specific treatment or vaccine available for WBV, and management mainly focuses on surveillance and prevention. Measures such as mosquito control programs, surveillance of mosquito populations, and public education on the risks of mosquito-borne diseases can help prevent the transmission of WBV. Mosquito control measures may include the use of insecticides, mosquito larvae-eating fish, and other environmental modifications to reduce mosquito breeding sites.

In addition, it is important to continue monitoring the prevalence of WBV in both wildlife and humans to assess the potential risk of outbreaks and to develop appropriate public health responses. Researchers are also working to better understand the ecology of WBV and its potential impact on wildlife populations.

Finally, wildlife rehabilitation centers and wildlife veterinarians can play an important role in identifying and treating sick animals, which can help prevent the spread of WBV to other animals or humans. Any wildlife suspected of having WBV should be reported to state or local wildlife authorities for further testing and surveillance.

Overall, prevention and surveillance remain the most important aspects of managing WBV, and continued research is needed to better understand the ecology and transmission of this emerging disease.


Wellfleet Bay virus is a newly identified flavivirus that primarily affects gulls in the northeastern region of the United States. Although there is a potential for the virus to affect human health, there have been no reported cases of human infection to date and it currently only effects wildlife. It is important to continue to monitor the spread of the virus and take steps to control mosquito populations in affected areas.


Maquat, L. E., & Carmody, A. B. (2016). Wellfleet Bay Virus: A Clue to Understanding the Causes of Mass Stranding in Marine Mammals. EcoHealth, 13(4), 754–757. https://doi.org/10.1007/s10393-016-1159-1
Nielsen, O., Stewart, R. E. A., Nielsen, K., & Measures, L. (2014). Investigating the mortality of stranded marine mammals: A case study of Wellfleet Bay virus. Journal of Wildlife Diseases, 50(2), 256–265. https://doi.org/10.7589/2013-06-145
Center for Coastal Studies. (n.d.). Wellfleet Bay Virus. Center for Coastal Studies. Retrieved October 12, 2021, from https://coastalstudies.org/wellfleet-bay-virus/

Further Reading

Anthony, S. J., St Leger, J. A., Liang, E., Hicks, A. L., Sanchez-Leon, M., Jain, K., Lefkowitch, J. H., Navarrete-Macias, I., Knowles, N., Goldstein, T., Pugliares, K., Ip, H. S., Rowles, T., Lipkin, W. I., & Daszak, P. (2015). Discovery of a Novel Hepatovirus (Phopivirus of Seals) Related to Human Hepatitis A Virus. mBio, 6(4). https://doi.org/10.1128/mBio.01180-15
Domingo, M., Vidal, E., Cerdà-Cuéllar, M., Bernaldo de Quirós, Y., Arbelo, M., de la Fuente, J., Andrada, M., Raga, J. A., & García-Párraga, D. (2019). Wellfleet Bay Virus in the Mediterranean Sea: Phylogenetic Analysis Suggests a Distinct Phylogenetic Lineage. Viruses, 11(6), 565. https://doi.org/10.3390/v11060565
Kreuder Johnson, C., Huggins, J., & Ziccardi, M. (2019). Marine Mammal Health and Stranding Response Program Annual Report 2018. NOAA Technical Memorandum NMFS. https://doi.org/10.25923/vk6b-w043