Swine Medicine Update

As you may have heard, there is a bit of an epidemic of a new virus in the swine industry currently.  Seneca Valley Virus (SVV) has been diagnosed in several states in the past few months (but not in Indiana).  There have been multiple cases in both commercial and show pigs.  This virus presents exactly like Foot and Mouth Disease or other similar vesicular diseases that are considered foreign animal diseases (FAD) in the US. 

SVV is not an FAD and therefore does not cause quarantines or other regulatory action.  However, if there are clinical signs of this virus, swine veterinarians will pursue diagnostics to rule out any FAD.  Veterinarians will work with the State Veterinarian and/or USDA APHIS Assistant District Director to review the situation.  Further, the treating herd veterinarian will work closely with the producer to isolate the area, document and collect samples for testing and diagnosis. The majority of animals will recover from this disease in 7-10 days. 

This virus has actually been present in the US since 1988, although very few cases were documented.  To date in 2015, there has been 20-30 SVV positive case submissions associated with clinical signs in swine.  This is not an extremely high number of cases, but is significantly greater than the 2-3 sporadic cases per year typically seen by diagnostic laboratories.  SVV is not known to cause any human disease and meat from infected animals is safe for human consumption.

This event demonstrates the importance of the collective work of veterinarians, producers, and state/federal officials to provide the safest food supply in the world.  If you wish to know more about SVV, please visit the Swine Health Information website at http://www.swinehealth.org/.

An Afternoon of Infectious Disease: Part II – Multidrug-Resistant Infections

By Dr. Nicola Parry

On August 19^th, the IVMA hosted its 2^nd annual CE event at the Indiana State Fair, An Afternoon of Infectious Disease, presented by Lynn Guptill, DVM, PhD, Associate Professor of Small Animal Medicine at Purdue University College of Veterinary Medicine. During the second half of the session, Dr Guptill talked about multidrug-resistant infections (MDRIs).

Multidrug-resistant organisms (MDROs) are defined as microorganisms, predominantly bacteria, that are resistant to one or more classes of antimicrobial agents. They represent a growing public health threat worldwide, and overuse of antibiotics represents the single most important factor leading to antibiotic resistance.

In 2013, the Centers for Disease Control and Prevention (CDC) reported that at least 2 million Americans fall ill from antibiotic-resistant bacteria every year, and that at least 23,000 die as a result of those infections. The CDC report emphasized that antibiotic resistance is rising for many pathogens that are threats to health, and in the US it adds about $20 billion in excess direct healthcare costs. In addition, the problem could get worse before it gets better. The report also indicated that up to half of antibiotic use in people, and much of antibiotic use in animals, is unnecessary and inappropriate. Stopping just some of this use would help significantly in slowing down the spread of MDROs. Indeed, the report noted that preventing the misuse of antibiotics is likely "the single most important action needed to greatly slow down the development and spread of antibiotic-resistant infections."

The proportion of MDROs causing infections in animals has continued to increase, and in recognition of this increasing global threat, in 2014, the White House announced the National Strategy for Combating Antibiotic-Resistant Bacteria (CARB). The US Food and Drug Administration’s Center for Veterinary Medicine is integrally involved in this strategy, and has engaged in various activities to address the issue.  

Dr Guptill highlighted some common examples of antibiotic misuse of antibiotics in veterinary practice, including their use to treat conditions that are typically viral-induced—such as upper respiratory tract infections in cats—as well as in other instances where they are unlikely to be needed—such as lower urinary tract infections in cats. In addition, it has become increasingly common in veterinary medicine to prescribe 2 or more antimicrobial agents when fewer agents would suffice.

Risk Factors for MDRIs in Animals

The best data about risk factors for development of MDRIs in animals pertain to Staphylococcus species. Reported risk factors include:

·       Any use of antibiotics

o   The risk is elevated with additional antibiotic treatment courses

·       A recent visit to a veterinary clinic

o   In particular if the visit occurred within 30 days of diagnosis

o   Risk is also related to the number of employees in the clinic, and increases in association with visits to clinics comprising more than 10 employees

·       Hospitalization

o   The risk increases as hospital stay lengthens

·       The use of surgical implants

·       Contact with people who are infected with MDRIs

What Can We Do To Reduce The Problem?

One of the inherent problems of MDRIs is that their clinical signs are non-specific, said Dr Guptill, noting that MDRIs are an emerging threat in veterinary practice, and that nosocomial infections continue to be a problem in veterinary facilities. When dealing with animals with, or suspected of having, MDRIs, she emphasized the need for good hygiene practices, including hand-washing, covering lesions, and warning owners not to kiss their pet or allow it to lick them, and to keep the pet off their bed. Just hand-washing after every encounter with an infected animal or person can reduce the risk of transmission of infection by 80% to 90%, she said.

She also stressed that veterinarians should modify prescribing behaviors in order to hopefully prevent the need for federally-enforced regulation of antimicrobial use. Such strategies may include careful review of culture results and the use of antimicrobial stewardship programs. Veterinary personnel should also be educated about, and familiar with, the potential for zoonotic or anthroponotic infections. And in cases where an MDRI is suspected, early culture and avoidance of prolonged empiric antimicrobial therapy are key. In particular, where possible, it is necessary to avoid treating infected animals with antimicrobials that are considered critically important in people, namely vancomycin, carbapenem, and 3^rd generation cephalosporins, Dr Guptill concluded.