One-health Approach Helps Address Zoonotic Disease

According to the U.S. Centers for Disease Control and Prevention (CDC), 75% of emerging infectious diseases of people are zoonotic, or originated with animals. Environment also affects the distribution of pathogens and their vectors, making the One-Health approach the ideal basis for addressing these diseases.

In late 2017, the USDA, CDC and the U.S. Department of the Interior (DOI) organized a One Health Zoonotic Disease Prioritization (OHZDP) workshop involving experts from the human-, animal- and environmental-health sectors. This week, the CDC issued its U.S. One Health Zoonotic Disease Prioritization Report, summarizing the group’s efforts to assess relative risks and develop an objective system for prioritizing and addressing zoonotic diseases.

Workshop participants identified these zoonotic diseases as top priorities for the United States:

1. Zoonotic influenza – Influenza A viruses primarily affect poultry and pigs
2. Salmonellosis -- This is one of the most important foodborne diseases in the United States, potentially infecting virtually all livestock including ruminants, pigs and poultry.
3. West Nile virus – Wild birds serve as the primary reservoir for this mosquito-borne virus. Among livestock species, West Nile virus primarily affects equids.
4. Plague – The Yersinia pestis bacteria rarely affects humans in the United States, but has epidemic potential and the U.S. Department of Health and Human Services (HHS) classifies it as a tier 1 biological agent on its Select Agents and Toxins list. Wildlife such as ground squirrels and prairie dogs carry the bacteria, with fleas serving as vectors for human infection.
5. Emerging coronaviruses – These include severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). Animals such as camels (MERS) and cats (SARS) are known carriers, but these do not appear to affect U.S. livestock.
6. Rabies – According to the report, rabies affects about 40,000 to 50,000 people in the United States annually, at a cost of about $510 million. Wildlife species such as raccoons and bats, and the disease can affect cattle and horses as well as pets.
7. Brucellosis -- Brucella abortus, the most important Brucella species in the United States, mainly infects ruminants. Wildlife species, primarily elk and bison, serve as reservoirs for potential transmission to cattle. While national herd prevalence in cattle is less than 0.0001%, the number of affected herds has been increasing since 2005.
8. Lyme disease – This tick-borne bacteria (Borrelia burgdorferi) is the most common vector-borne pathogen in the United States. Cattle appear to resist the disease, with wild animals serving as the primary hosts.

The team used the following criteria ranking U.S. zoonotic diseases in order of importance.

1. Pandemic/Epidemic Potential.
2. Severity of Disease in Humans, Domestic Animals and Wildlife, including disease mortality or population impact in humans, domestic animals or wildlife, and the incidence of the disease in humans or animals in the United States.
3. Economic Impact to the United States.
4. National Security.

Over the next three years, the report’s authors recommend developing a U.S. One-Health Security National Action Plan, establishing a One-Health Coordinating Mechanism for the United States, publishing a National One Health Framework and continuing collaboration to advance One Health in the United States.

Find the full report online from the CDC.

For more on One Health and zoonotic diseases, see these articles from BovineVetOnline:
Resistance Grows Among Zoonotic Pathogens

One stop shop for 'One Health' approach to zoonotic threats

Taxonomy Could Predict Virulence of Multi-host Pathogens