From ASF to COVID: How NAHLN Protects Animal Agriculture
The U.S. livestock and food sectors account for more than $150 billion in annual cash receipts. It’s no wonder threats of foreign and emerging animal disease outbreaks are increasingly making headlines these days.
Since 2002, the National Animal Health Laboratory Network (NAHLN), created through the cooperation of the USDA-APHIS Veterinary Service, USDA’s National Institute of Food and Agriculture (NIFA), and the American Association of Veterinary Laboratory Diagnosticians (AAVLD) has been helping protect these agricultural assets.
NAHLN, a network of federal, state and university-associated veterinary diagnostic laboratories that provide ongoing disease surveillance, responds quickly to disease events; communicates diagnostic outcomes to decision makers; and has the capability and capacity to meet diagnostic needs during animal disease outbreaks, NIFA wrote in its latest update.
Since it started, NAHLN has grown from 12 AAVLD laboratories to 60 AAVLD laboratories throughout the U.S. capable of testing large numbers of samples for specific disease agents.
Here are three ways NAHLN has been moving the needle to protect U.S. animal agriculture.
1. African Swine Fever
African swine fever, or ASF, is a devastating, highly infectious animal disease that, if found in the U.S., would be devastating to the multibillion-dollar pork industry. While ASF poses no threat to human health, its impact on U.S. pig populations — and the domestic and foreign markets that depend on them — would be severe. Economists suggest that losses to the pork industry could be as high as $50 billion if we are unable to contain and eliminate ASF in a 10-year scenario.
Since the first known outbreak in 1907, ASF has infected swine in Africa, Europe and Asia. The virus was recently discovered on the Caribbean Island of Hispaniola— first in the Dominican Republic and in Haiti in September. Previous outbreaks in other countries have resulted in devastating swine losses for pork producers through both high mortality and significant culling to control the spread of the disease, NIFA said.
On June 1, 2019, APHIS implemented an active ASF Surveillance Program within NAHLN that supplemented an already existing classical swine fever (CSF) surveillance program. This program tests diagnostic lab submissions for the presence/absence of ASF and CSF via a real-time polymerase chain reaction (PCR), the report said.
In addition, with support from NIFA, APHIS Wildlife Services is seeking to develop a disease spread model focused on populations of feral swine. The project’s goal is to provide responders across the nation with a toolbox to rapidly eliminate the ASF virus if an introduction were to occur.
2. Antimicrobial Resistance
Antimicrobial resistance (AMR) of bacterial pathogens is an emerging public health threat to people and animals because it compromises the ability to treat infections, NIFA explained. Antimicrobial resistance surveillance programs in the U.S., such as the National Antimicrobial Resistance Monitoring System (NARMS), have traditionally focused on collecting data from healthy food animals, retail foods and people.
In March 2015, the Executive Office of the President released the National Action Plan for Combating Antibiotic-Resistant Bacteria (CARB), with the primary purpose to guide activities and actions by the government, public heath, healthcare and veterinary partners to address the AMR threat. The National Action Plan set five main goals and charged all federal agencies to collaborate to identify emerging resistance with the goal of increasing antimicrobial stewardship.
NAHLN, as a result, initiated the NAHLN AMR pilot project in January 2018, which is on track to be converted to a permanent program early in 2023, NIFA noted. The project monitors data from four livestock species (cattle, swine, poultry and horses) and two companion animal species (dogs and cats).
Establishing a surveillance program within NAHLN to monitor AMR profiles in animal pathogens will enhance the nation’s early detection of, response to, and recovery from animal health emergencies. It will also help identify new or emerging AMR profiles and help monitor continued usefulness of antimicrobials over time.
3. SARS-COVID
The NAHLN network entered uncharted territory by heeding a call for help from human diagnostic laboratories to increase human testing capacity for SARS-CoV-2 or COVID-19 within the U.S. Many NAHLN labs utilize high-throughput PCR testing for various animal pathogens, which is not a common practice among their human counterparts, NIFA wrote.
Each laboratory independently obtained Clinical Laboratory Improvement Amendments approval, and many took on all human testing for their states. NIFA said some also performed next generation sequencing, aiding in the identification and tracking of viral mutations, including detection of the Delta variant as it spread across the country. By October 2021, 33 NAHLN laboratories were conducting SARS-CoV-2 testing; 22 of those for human samples, and 26 testing for the virus in animals.
