Exotic Newcastle Disease

Virulent Newcastle disease (VND), formerly known as Exotic Newcastle Disease, and African Swine Fever outbreaks continue to impact poultry in California and hogs in China, respectively.  Notably, these diseases are largely not infectious to humans, but nevertheless are impacting farmers, ranchers, hobbyists, national and internal markets.

California has been trying to stamp out VND since last May.  Unfortunately, the outbreak, which initially infected only backyard breeders and owners, has since spread to some commercial flocks.  As reported by the California Department of Food and Agriculture (CDFA), “[s]ince May 2018, USDA/APHIS and CDFA employees have been working seven days a week in Southern California to eradicate virulent Newcastle disease in backyard birds, and to protect commercial facilities.”

Virulent Newcastle disease (VND), formerly known as Exotic Newcastle Disease, is a serious, highly contagious viral disease that can affect poultry and other birds. In rare cases, humans that have exposure to infected birds may get eye inflammation or mild fever-like symptoms. These signs generally resolve without treatment, however, medical care should be sought if symptoms persist. Infection is easily prevented by using standard personal protective equipment. Virulent Newcastle disease is not a food safety concern. No human cases of Newcastle disease have ever occurred from eating poultry products. Properly cooked poultry products are safe to eat.

This is not CDFA’s first rodeo with VND.  From 2002-2003, VND outbreaks in back yard flocks and commercial poultry operations in Southern California, Arizona, Nevada and Texas “led to the depopulation of 3.16 million birds at a cost of $161 million” before the outbreak was successfully eradicated.

Since the current VND outbreak has persisted, despite a robust state and federal response, the California State Veterinarian has announced the following additional draconian measures in an attempt to contain this outbreak:

Due to progression and duration of a virulent Newcastle Disease (VND) outbreak in parts of Southern California, the State Veterinarian has ordered mandatory euthanasia of birds in neighborhoods in Compton (Los Angeles County), Muscoy (San Bernardino County), Mira Loma/Jurupa Valley (Riverside County)       Perris (Riverside County).

Unfortunately, even if birds and flocks have previously tested negative but now fall within a designated mandatory euthanasia area, the birds must be euthanized. USDA/CDFA staff will contact affected bird owners.

While this action is difficult for all involved, it MUST be done to eradicate VND. Otherwise, the disease will continue to spread and kill additional flocks.

When depopulation of flocks is mandated to contain such a devastating outbreak it is very difficult on animal owners as well as the animal health officials involved.

Parallel measures have seemingly been deployed in China, where African Swine Fever was first confirmed in more than 50 cases since August 2018.

According to USDA, African Swine Fever was “first described in the 1920s in Kenya, is a highly contagious hemorrhagic disease of wild and domestic suids with extremely high morbidity and mortality rates. ASF is a notifiable disease with the World Organization for Animal Health (OIE) due to its ability to spread rapidly and cause severe illness. ASF does not pose a risk to public health.”

Similar to concerns about the spread of Foot and Mouth Disease virus in the UK in 2001—considered the most contagious virus affecting animals—ASF can be spread by people or equipment not properly decontaminated.  Because of such concerns, the USDA and U.S. pork producers and related associations have provided information to producers about how to protect their animals against accidental exposure.

ASF has reportedly “infected 100 farms across China since August 2018, spreading faster than in any other country to date.”  

The National Pork Producers Council reported

On August 3, 2018, China reported their first case of ASF. By August 23, 2018 there were four outbreaks reported, and more are suspected. The outbreaks are in areas of China with large pig populations. APHIS, CBP and all other agencies with relevant authority are monitoring movements of people and goods from these areas to guard against an ASF outbreak in the United States. ASF does not infect people or other animals, and there are no food safety implications.

USDA has posted several guidance documents regarding its response to the ASF outbreak, available here.

A list of tasks intended to prevent the importation of infected or contaminated products, include the following precautionary measures:

APHIS import restrictions prohibit the entry of untreated animal products, including meat and meat products, from countries or regions considered affected with certain diseases. Fresh/frozen pork is prohibited from regions affected with FMD, CSF, SVD, or ASF, while meat that has been cooked is allowed under APHIS regulations.

Swine casings that originate from ASF positive countries/regions are prohibited entry into the US under APHIS regulations.

APHIS acted to deny entry of Chinese origin swine casings in transit when ASF was found in China.

A comprehensive list is available at usda-industry-prevention-points.pdf.

A virulent form of Newcastle disease (vND), “a contagious and fatal viral disease affecting the respiratory, nervous and digestive systems of birds and poultry,” as described on USDA’s Virulent Newcastle Disease webpage has been confirmed in 93 cases in backyard exhibition chickens and turkeys by USDA since May 18, 2018.

The last outbreak of vND started in 2002 infecting 22 commercial premises and hundreds of backyard flocks, at a cost of over $180 million dollars to eradicate the outbreak, officially ending on March 26, 2003.  That outbreak, which started in California spread to four other states, but the majority of affected premises were in California.

Since May of this year, USDA has been regularly updating its stakeholders with information about the current outbreak, which to date, has not infected commercial poultry premises.

USDA reports that vND (previously called Exotic Newcastle Disease or END) “is one of the most infectious diseases of poultry in the world and is so deadly that many birds die without showing any signs of disease. A death rate of almost 100 percent can occur in unvaccinated poultry flocks. It can infect and cause death even in vaccinated birds.”

There are “three simple steps” USDA describes to prevent the disease from spreading to other flocks including:

Washing hands and scrubbing boots before and after entering an area with birds;

Cleaning and disinfecting tires and equipment before moving them off the property; and

Isolating any birds returning from shows for 30 days before placing them with the rest of the flock.

Bird owners are directed to contact state and federal animal health officials if their birds exhibit the following clinical signs:

Sudden death and increased death loss in flock

Sneezing, gasping for air, nasal discharge, coughing

Greenish, watery diarrhea

Decreased activity, tremors, drooping wings, twisting of head and neck, circling, complete stiffness

Swelling around the eyes and neck.

USDA also amended Veterinary Services Memorandum No. 800103 “Reissuance of Product Licenses for Autogenous Products and Guidance Concerning Restriction on the Production and Use of Veterinary Biologics,” seemingly related to concerns about the use of some virulent viruses in autogenous vaccines.

VS Memorandum 800.103 was signed on July 18, 2018, and cancels VS Memorandum 800.103 dated May 28, 2002. This memorandum provides guidance to licensees, permittees, and applicants concerning Animal and Plant Health Inspection Service’s restrictions on the production, importation, distribution, and use of autogenous biologics. This memorandum is effective immediately.

As described in Memorandum 800.103:  

APHIS restricts the importation and distribution of veterinary biologics from countries known to have exotic diseases, including, but not limited to, foot-and-mouth disease, rinderpest, highly pathogenic avian influenza, swine vesicular disease, Newcastle disease, African swine fever, and bovine spongiform encephalopathy if, in the opinion of APHIS, such products may endanger domestic animals, livestock, or poultry.

In addition, APHIS restricts the production and distribution of veterinary biologics, including, but not limited to, Brucella Abortus Vaccine, Vesicular Stomatitis Vaccine, and certain diagnostic products used in cooperative State/Federal/industry animal disease control and eradication programs, if it determines such products may interfere with disease surveillance and/or control and eradication efforts.

The instant amendments appear to be an attempt to prevent potentially virulent virus from inclusion in autogenous vaccines (a reasonable limitation).  Therefore, field isolates intended for inclusion in such products must be tested at an APHIS-approved laboratory before such use.

Hopefully, this outbreak will be resolved soon and without infecting more backyard or commercial-raised birds.