White House antibiotic resistance action plan

The White House has released a "National Action Plan for Combating Antibiotic Resistant Bacteria". It will be interesting to see how much actual 'action' comes from it, but it's great to see the subject getting addressed at such a high level.


Pet treats...what to look out for

Pet treats are widely used, and for good reason. They can be good training tools and pets tend to like them. There are also some risks. As with most of what I talk about here, balancing risk and benefit is the key.

So, what are the concerns?

Pathogens

  • I have to start with this one, since worms and germs are what we deal with here. Pet treats have been implicated in a few different outbreaks in people. Salmonella contaminated pig ear treats are the main offender, but any animal-based treat that is not processed to kill pathogens (e.g. cooking, pasteurization, irradiation) is a concern.
  • While pig ears used to be the main issue, now, you can go into some pet stores and get dehydrated ‘insert almost every body part here’….lung, trachea, liver, ear… Presumably those carry a similar degree of risk for Salmonella if they are not cooked, pasteurized or irradiated.

Toxins

  • The main concern here is chicken, duck and sweet potato jerky treats from China, since they have been implicated in a large number of illnesses and deaths, including at least 1000 dead dogs. No reason for the Fanconi-like syndrome associated with these treats has been identified (and therefore there’s no way to test).

Injuries

  • Hard treats can result in tooth damage or fractures, which can be both painful and expensive to address.
  • Damage to the intestinal tract can occur with sharp objects (e.g. bone fragments).

Obstructions

  • Dogs eat stuff they’re not intended to all the time (at least mine does). Most often, that’s not a problem. Sometimes, it is. One of the potential problems in obstruction of the intestinal tract if a large piece of a poorly digestible treat is ingested. Realistically, this is of limited concern for treats and is a bigger issue with toys and things like rawhides.

Obesity

  • This isn’t usually considered when thinking about problems with treats, but treats can be calorie dense, and obesity isn’t just a problem with pet owners. As with human snacking, moderation is the key. As was demonstrated in a recent study of bully sticks (dried bull penis), size matters, since the treats contained 9-22 calories per inch (Freeman et al, Can Vet J 2013).

Thinking about the treat, how to use it and what problems might occur is a good idea. Most treats, particularly those that are not raw animal product based (e.g. pig ears), not prone to fragmenting (e.g. bones, especially cooked bones) and not excessively hard (e.g. bones) are ok in moderation.

One question that’s come up recently is whether pig hair can be a problem with treats.

Yes, there’s a bit of an ‘ick’ factor for some (although it’s a little odd to see people freak out about some hair then feed their dog a chunk of bull penis or the ear of a pig…).

But, is there a risk?

  • I can't see there being any realistic concerns.
  • A dog would have to eat a massive amount of hair-laden treats to have any potential concerns about obstruction (and realistically, I can't see it happening even with a pretty massive exposure).
  • Hair could be contaminated with various bacteria, like other raw animal parts, but if the treat is cooked (or otherwise treated to kill bacteria) that becomes irrelevant. Certainly, it’s fair to ask whether hair is supposed to be there but I wouldn’t get worked up about it. I’d be more concerned about whether the treat is processed to kill pathogens and fed in moderation (to reduce caloric intake more than hair intake).

 

Rat bite fever death

A recent rat bite fever death in a 6 month old Pennsylvania baby raises a few different issues that parents need to consider.

The child died of meningitis and myocarditis (inflammation of the heart) caused by the bacterium Streptobacillus moniliformis. This bacterium is present in the mouths of virtually all rats and is the cause of rat bite fever. Human infections are uncommon but they can be severe, especially in young individuals, people with compromised immune systems and/or when infection is not diagnosed promptly. Rat bite fever is (not surprisingly, given the name) mainly associated with bites, but can also come from contact of rat (or other rodent) saliva with mucous membranes (e.g. mouth, nose) or breaks in the skin.

In this case, the baby had been bitten by a rat that was to be fed to the family’s snakes.  A few days later, a fever and rash were noted (classical rat bite fever signs) and the child was taken to an Emergency Room, but discharged with ‘medication’ (probably just something to drop the fever). Two days later, the baby was returned to hospital with a fever and lethargy, and died later that day.

This case raises many relevant points

  • Babies should not have any contact with rats. Babies are at increased risk of infection from various things, would get little benefit from touching a rat and the risks outweigh any benefits.
  • If an infant is bitten by any animal, antibiotics are often indicated to prevent infection. Good bite first aid and knowing when to get medical care should be an integral part of pet ownership.
  • Pet owners need to know about infectious disease risks associated with their animals, especially when there are high risk people in the household.
  • Physicians need to know about bites and other animal exposures. It’s not reported whether the physicians asked, and given the fact that rat bite + fever + rash absolutely screams I HAVE RAT BITE FEVER, they must not have. 
  • Patients/parents need to volunteer information about pet ownership and high risk incidents like bites. If the physician had asked about animal contact or the parents had mentioned the bite, odds are good that the baby would have been treated for rat bite fever early in the course of disease and have survived. 
  • Live rodents should not be fed to reptiles. There are humane issues for both rat and snake, and snakes can be seriously injured by prey.

Regardless, snakes (or any other reptile) should not be kept in households with babies. The risk of Salmonella exposure is too high.

People talk about ‘one medicine’ all the time, but application of it is poor. There needs to be better communication about zoonotic diseases and animal exposure, especially in situations like this.

 

Antibiotics in animals: ACVIM consensus statement

Every year, the American College of Veterinary Internal Medicine (ACVIM) commissions "consensus statements" on specific topics. They’re developed by an expert panel, put up for review by ACVIM members (board certified veterinary internal medicine specialists), and published in the Journal of Veterinary Internal Medicine.

Hot off the (electronic) press is the 2015 ACVIM Consensus Statement on Therapeutic Antimicrobial Use in Animals and Antimicrobial Resistance. Assembled by an international group of experts in infectious diseases, microbiology, internal medicine and pharmacology, it’s an expansion on the highly regarded 2006 equivalent.

To download the consensus statement, click here.

 

Cats and peritoneal dialysis

If you’re a regular reader, you’ll note the recurring theme of "every animal (and person) is carrying multiple microbes that can harm you, given the right circumstances. Fortunately, the right circumstances don’t usually occur."

There are situations in which those risks increase, and understanding cost-benefit is a key aspect of disease prevention. Sometimes pet factors increase the risk, such as being of a certain species (e.g. most reptiles), young in age, or having an illness (e.g. diarrhea). Sometimes it’s human factors that increase the risk, such as immune status, poor animal handling practices, behavioural issues, or the impacts of diseases or medical treatments.

An example of the last one was published in a recent edition of the Canadian Journal of Infectious Diseases and Medical Microbiology (Poliquin et al 2015). It’s a review of peritoneal dialysis-associated infections caused by Pasteurella, a bacterium commonly associated with pets (especially cats). It doesn’t really tell us anything new, but it’s a reminder of the risks that are present in certain situations.

Peritoneal dialysis is a procedure used in some people with kidney failure. It involves placing a catheter into the abdomen through the body wall. Fluid is then put into the abdominal cavity through the catheter, and removed a short time later, taking with it various substances that would normally be removed by working kidneys. As opposed to hemodialysis, which removes these same substances directly from the blood, peritoneal dialysis can be done at home; however, the catheter has to be left in place and managed properly to prevent infection. Here’s where the pet risk comes in.

The Poliquin paper reviewed records of Pasteurella isolates from peritoneal fluid from patients in the the Manitoba (Canada) Renal Program from 1997-2013. They also looked at published reports of Pasteurella peritoneal dialysis-associated infections.

In total, they identified 37 cases: 33 caused by Pasteurella multocida and four caused by other Pasteurella species.

  • Affected patients had varying degrees of illness, with abdominal pain, nausea and vomiting being most common.
  • Two individuals also had bloodstream infections with P. multocida. One was very sick with a "shock-like syndrome."
  • Contact with a cat was implicated in 83% of cases.
  • Direct contact between a cat and peritoneal dialysis equipment was reported in 25 cases. Ten of these involved the cat puncturing (teeth or claws, presumably) the line or fluid bags.
  • Infections linked to a known bite or puncture of the tubing had a much quicker onset (15 hours vs 44 hours following other contacts).
  • Two people required an ICU stay.
  • The peritoneal catheter had to be removed in 11% of patients.
  • No one died.

As I said, nothing too surprising but more data to support some basic concepts:

  • There are lots of people on peritoneal dialysis living at home with cats. The incidence of this problem seems to be low. However, low incidence doesn’t help much if you’re the one with the infection. So, preventive measures are still worthwhile.
  • Pasteurella can be found in the mouth, nose and feces of most (or all) cats, so testing cats for the bacterium makes no sense. Trying to eliminate Pasteurella from its natural host would also be futile, so instead focus on keeping it out of the person’s abdomen.
  • Since direct contact was documented in most cases (and probably occurred in at least some of the other cases), keeping cats away from peritoneal dialysis catheters and all associated items is important. That should be easy to do, and is probably a key control measure.
  • Since Pasteurella is present in most or all cats, patients should practice good hygiene around their pets, especially hand hygiene. That’s particularly true before handling the peritoneal catheter site or any equipment.
  • Punctures of the tubing or other equipment should be considered a high-risk situation. Part one is keeping the cat away. Part 2 is getting medical advice when a puncture does happen, since prophylactic antibiotics might be indicated.

Image from www.mayoclinic.org (click for source)

 

Lungworms in Ontario dog

Another emerging infectious disease issue for the Ontario dog population appears to be lungworms. As you’d probably guess, lungworms are parasites that live in (or near) the lungs. A variety of different types of lungworms exist, but most concerns around here relate to two.

In Canada, both the fox lungworm (Crenosoma vulpis) and the French heartworm (Angiostrongylus vasorum) have been found in the Atlantic provinces for a while. However, this seems to be a new situation in Ontario, with a small but increasing number of reports of Crenosoma vulpis in dogs that have not been outside of the province. I haven’t heard about any Angiostrongylus cases in the province yet (and hope it stays that way - see why below).

Foxes are the natural reservoir of both of these lungworms. Like many parasites, lungworms have a rather bizarre life cycle. Adult Crenosoma worms live in the lungs and lay eggs. The eggs are then coughed up, swallowed and passed in feces. After being pooped out, the lungworm larvae infect snails. Dogs get infected by eating infected snails, as the larvae move from the intestinal tract and through the body to the lungs, where they mature and the whole cycle starts again.

It’s similar with Angiostrongylus, although the larvae can also infect frogs (when they feed on infected snails), and dogs can be infected by eating infected snails or frogs. After a dog swallows the larvae, they migrate into the bloodstream and make their way to the heart and arteries of the lung.

Typical signs of Crenosoma infection in dogs include a chronic or intermittent cough that’s not responsive to common treatments directed at bacterial or inflammatory diseases. Fortunately, Crenosoma infections are usually treatable with anti-parasitics, with a good outcome.

Angiostrongylus vasorum is a bigger concern, because infection can result in more severe lung disease, blood clots, heart failure and a few other bad things. Adult worms can also head to other parts of the body and cause more problems (but fortunately that's pretty uncommon).

If one or both of these parasites are established in the fox population in the province, lungworm is not going away. Understanding where it is present will be important for prompt diagnosis and to determine the best preventive medicine programs. As it stands now, lungworms have to be considered as a potential cause of chronic cough in dogs in Ontario. It’s still probably rare but is potentially treatable and something of which to be aware.

 

New pet therapy guidance

A new Expert Guidance Document has been released by the Society for Healthcare Epidemiology (SHEA) and published in Infection Control and Hospital Epidemiology.

R Murthy, G Bearman, S Brown, K Bryant, R Chinn, A Hewlett, BG George, EJC Goldstein, G Holzmann-Pazgal, ME Rupp, T Wiemken, JS Weese, DJ Weber. Animals in Healthcare Facilities: Recommendations to Minimize Potential Risks. Infect Control Hosp Epidemiol 2015

 The guidance document covers 4 main areas

  • Animal assisted activities (aka pet therapy, hospital visitation)
  • Service animals
  • Research animals in healthcare facilities
  • Personal pet visitation

The document provides recommendations for practices to reduce the risk of animal-associated diseases from these activities. There’s also some introductory survey information that highlights a few reasons why this guidance is important.

  • Pet therapy was allowed at 89% of surveyed US hospitals.
  • Personal pet visitation was permitted at 40%.
  • Research animals were present in 35%.
  • Many hospitals that allowed animals had no policy covering their activities.
  • All facilities that allowed pet therapy permitted dogs. 21% also allowed cats, 5% miniature horses and 2% primates (ugh!).
  • A few US facilities, including a Veteran’s Hospital, indicated that they did not allow service animals, something that contravenes the Americans with Disabilities Act.

This should be required reading for anyone involved in hospital administration, hospital infection control or pet therapy programs.

 

Out of bounds, out of luck

From CTVnews.ca "A Brazilian [soccer] player was taken to a hospital for an anti-rabies shot after being bitten by a police dog during a match. The incident happened in the second half of a first-division game between Democrata and Tupi on Sunday in the Minas Gerais state regional championship. Democrata striker Joao Paulo was bit on his left arm after running out of bounds and falling too close to a police officer's dog behind one of the goals. The dog was on a leash but the officer was not able to pull it back in time to avoid the attack. Joao Paulo returned to the match after doctors wrapped his arm in bandages, but the team said he was taken to a hospital immediately after the game to receive the anti-rabies vaccine.”

Oops, on a few different levels.

Firstly, it’s surprising that a police dog would bite in a situation like this. They’re not typically trained to attack in the face of soccer field boundary transgressions.

Secondly, the medical response is a bit bizarre. Yes, rabies needs to be considered after any bite from a dog. You’d hope the police dog was vaccinated against rabies, making it a pretty low risk situation. Regardless, rabies post-exposure prophylaxis is completely unnecessary. Presumably, they’d be able to quarantine and observe the police dog for 10 days. If they can do that, there’s no need for rabies treatment. If the dog’s not showing signs of rabies after 10 days, it could not have been infectious at the time of the bite. That’s a lot more logical response than treating the bitten player.

What the player really needed was proper bite first aid. Placing a bandage on might be the quickest way to get him back on the field, but properly flushing the wound is the best way to prevent infection (something that could keep him off the field much longer).

 

Communication done right: EVH-1 in Minnesota

Two cases of EHV-1 have been detected on a farm in Prior Lake, Minnesota.  There aren't a lot of details about the cases, other than one horse was put down, and the other was taken to the University of Minnesota veterinary hospital for treatment and has apparently recovered and is ready to come home.

The barn is being monitored by the Minnesota Board of Animal Health for the next three weeks, which is the typical recommended quarantine period after the last case has either been removed or isolated from the rest of the animals.  Hopefully during this time the rest of the horses will get twice-daily temperature checks to ensure any other animals that may have been infected are detected and isolated as soon as possible.  Other routine infection control practices are hopefully also in place, such as hand hygiene between handling animals, and not sharing equipment between stalls and horses (particularly things like water/feed buckets, twitches, grooming supplies etc.).  These practices should be in place all the time, but they frequently get extra attention in outbreak situations.

The remarkable part about this case is what the stable owner did after the disease was diagnosed.  Instead of trying to keep it quiet or cover it up, she not only reported it to the Board of Health, but she also called everyone who visited the farm and the local veterinary hospitals, and even posted information on facebook to let everyone know what was going on.  Fantastic!  Part of the reason for being so proactive may be that the local horse expo last April was close to empty due to cases of EHV in the area affecteing 14 horses.  It is great to see someone reaching out like this to give the community a "heads up" so that others will keep a closer eye on their animals and hopefully prevent spread of the disease.  Hopefully she did it in an informative manner, and along with announcing the problem also told people about the plan to contain it.  It's always important to include the plan of action so the news itself doesn't incite panic.

Mad Cow in Alberta

Last week the Canadian Food Inspection Agency (CFIA) announced that a case of bovine spongiform encephalopathy (BSE), more commonly known as Mad Cow Disease, was found in an Alberta beef cow

BSE belongs to a group of diseases called transmissible spongiform encephalopathies (TSEs) that are not caused by bacteria, viruses, fungi or parasites, but rather by abnormally-shaped proteins call prions.  Prions are extremely difficult to destroy, and they can't be killed using antimicrobial drugs because they aren't actually microbes.  Exposure to the prions, most commonly through ingestion, can lead to spread of disease.  That's why Canada banned the use of most animal proteins (specifically from most other mammals) from use in cattle feed back in 1997, in order to decrease the risk of BSE spreading if it ever got into the Canadian cattle population.  In 2003 an enhanced feed ban was introduced after the first case of BSE was found in a Canadian cow.  The ban prohibits "specified risk materials" (SRM) from cattle from entering the human food chain AND from being used in animal feeds.  The SRM includes all the tissues where prions would most likely be found, such as the brain and spinal cord, in animals over 30 months of age.

Most TSEs seem to be relatively species specific, but there is still a lot we don't know about them.  Unfortunately, there is strong evidence that the prion that causes BSE can cause disease in people, called variant Creutzfeldt-Jacob disease (vCJD).  The "variant" differentiates this disease from sporadic or familial CJD, a rare human disease that has been recognized since the 1920s.  Just over 200 cases of vCJD have been diagnosed since it was first detected in 1996, most of which occurred in Great Britain.  There is currently no evidence that these prions can cause disease is dogs or horses, but they do appear to be the causative agent of a similar disease in cats (feline spongiform encephalopathy (FSE)).  Given that these prions have crossed at least two species barriers (people and cats), the possibility that they could affect other species as well cannot be dismissed.

What will be the impact of this single case in Alberta?  Hopefully not much.  The World Organization for Animal Health considers Canada a controlled BSE risk country, and one case won't change that status.  Canada has an extensive surveillance system through which more than 30 000 cattle are tested every year for BSE, and this is the first case detected in 4 years.  This case was in fact a good example of the surveillance system in action - the case was detected before any part of the cow (not just the SRM) was allowed to enter the food chain.  The Canadian food supply is still very safe, as is the animal food supply.  The worrisome part of this case is that the cow was born in Alberta in 2009, well after the enhanced feed ban was put in place.  So the question is, how did the cow get exposed to the prions?  Cases can rarely also occur sporadically in cattle (as for classical CJD in people), could this have been one of those?  The incubation period for BSE is typically years, so the investigation is focusing a lot on the farm of origin, not just the farm where the cow last resided. This is where the ability to trace animal movement and movement of animal products becomes so important, as they are in so many disease investigations.