July 30, 2019 Update:

Wright County/Swartout Lake:  A second set of carcass samples were collected from Swartout Lake cormorants as the mortality event continues.  All samples were positive for vNDV. 

Meeker County/Pigeon Lake:  Samples from 2 cormorants and 1 pelican were submitted to the NWHC for testing, all samples were negative for NDV.  Other tests are still pending, these include West Nile Virus, salmonella, and avian cholera. 

NDV Biosecurity Measures:  The DNR has issued some biosecurity recommendations to their employees as a reminder for staff that may be handling dead or sick birds.  These recommendations include:  1)  Carcasses (unless being submitted to a lab for testing) must be disposed of via incineration or burial on site.  Under no circumstances, other than for laboratory submission, should they leave the site; 2) Specific cleaning and disinfection procedures for sample collection, vehicles, employees and equipment; 3) Employees involved in these mortality events should avoid contact with domestic birds (including poultry and “pet” birds) for two weeks, avoid pet stores, poultry operations (including confinement and range operations) and live bird markets.

The information below this point is from the Disease Alert sent July 26, 2019.

Virulent Newcastle Disease virus (vNDV) in double-crested cormorants (DCCO)

The Minnesota Board of Animal Health has been informed that Virulent Newcastle Disease virus (vNDV) in double-crested cormorants (DCCO) has been confirmed in a Minnesota county (Wright) and is suspected in another Minnesota county (Meeker).  Details from the Minnesota Department of Natural Resources (DNR) and the National Wildlife Health Center (NWHC) in Madison, WI follow:

Wright County, Albion Township near Maple Lake, MN / Lake Swartout:  The Board was notified of dead DCCO on Lake Swartout on July 8, 2019.  The Board contacted the DNR who collected carcasses for submission to the NWHC.  Lake Swartout is a shallow lake, no public boat access in Wright county.  Great egret, blue heron, and black crowned night herons nest on the island.  Clinical signs seen in the DCCO were the inability to move and twisted necks.  It was estimated that 50 DCCO were dead in a population of approximately 1,500.  Testing at the NWHC was preliminary positive for the APMV matrix gene and the F-gene, an indicator of virulence, by rRT-PCR. The NWHC submitted samples to the National Veterinary Services Laboratory (NVSL) in Ames, IA for confirmation.  rRT-PCR APMV-1 matrix results were detected at NVSL with CTs of 28.3 and 26.1.  The rRT-PCR vNDV results were detected on one of the two samples with a CT of 34.5.  

Meeker County, Collinwood Township near Dassel, MN / Pigeon Lake: July 21, 2019 – The DNR reported that DCCO and pelicans on Pigeon Lake were experiencing mortality, the inability to move and twisted necks.  Samples have been sent to NWHC for testing, results pending.  

History of vNDV in Minnesota double-crested cormorants

Double-crested cormorants (DCCO) seem to be highly susceptible to Newcastle Disease virus (AMPV-1) and it has been observed in this species in the past in Minnesota (2008, 2010, 2012, 2014, 2016, 2018).  vNDV was last detected in Minnesota DCCO in 2018 from Chautauqua (Lye) Lake near Fergus Falls (Ottertail County, Minnesota).  Historically the time of the year of these reports is similar (July – August).  In 1992, multiple mortality events occurred in DCCO colonies across the Great Lakes, upper Midwest and Canada, killing an estimated 35,000 birds. 

Poultry Producers

Virulent Newcastle Disease (vNDV) is a highly contagious, viral disease that affects all species of birds.  The disease spreads rapidly and causes high mortality, sometimes without the birds showing prior signs of sickness.  vNDV is spread primarily through direct contact between healthy and sick birds through droppings and secretions from the beak, mouth, and eyes.  Birds infected with vNDV may show any of the following symptoms: sudden death, lack of energy and appetite, decreased egg production, diarrhea, nervous system disorders (tremors, paralysis), and severe respiratory symptoms such as nasal discharge, coughing, and sneezing.  Although Newcastle disease rarely affects people, it has been known to infect individuals who have had close contact with sick birds.  Symptoms include conjunctivitis, a relatively mild inflammation of the inner eyelids.

Wild birds can be a potential source of Newcastle disease and can transmit the virus to domestic poultry if there is contact with them.  The Board recommends poultry producers, large and small, increase their on-farm biosecurity practices to prevent introductions into their poultry operations.  Such practices include visitor and vehicle restrictions, preventing wild bird introductions (especially birds that tend to nest in or feed with domestic birds), controlling movements associated with the disposal and handling of bird carcasses, litter, and manure and monitoring poultry flocks for any signs of illness.  Testing sick birds at a poultry diagnostic laboratory is essential in order to establish an accurate disease diagnosis. 

It is important poultry producers keep a watchful eye on their own flocks, as well as wild birds in their area.  Through careful biosecurity measures and diligent observation, Minnesota’s poultry producers can prevent the introduction of this disease into their poultry operations.  If producers observe poultry showing any of the clinical signs listed above, they should immediately contact their veterinarian, the Board (320-231-5170) or the University of Minnesota Veterinary Diagnostic Laboratory (1-800-605-8787).

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