More hatching chick associated salmonellosis

The salmonellosis outbreak in the US associated with hatching chicks continues to expand. The outbreak, ironically associated with Mt. Healthy Hatcheries in Ohio, has now sickened at least 344 people in 42 US states and Puerto Rico with a variety of Salmonella serotypes (S. Infants, S. Newport and S. Hadar). Showing no sign of abating, another 42 cases were identified in the past 6 weeks.

As is often the case, young people are more often affected, with 33% of sick individuals being 10 years of age or younger. 32% of infected individuals have been hospitalized.

Unfortunately, the regulatory response is most often giving places like this guidance as opposed to mandatory measures. However, this is really a ‘buyer beware’ situation, where people purchasing hatching chicks need to be aware of the high risks associated with young poultry and take appropriate measures. While Salmonella-free eggs and chicks would be ideal, it’s not particularly realistic, and people need to be proactive and listen to established infection control practices, which include keeping kids <5 years of age away from young poultry.

Maybe schools will pay attention to this when they’re planning their annual (and often poorly managed) hatching chick activities.

Parvo poop and the outdoor environment

Here’s a question that I get commonly: “What do I do to an outdoor area that might have been contaminated by a dog with parvovirus?”

There’s not a lot of research to back anything up, but understanding the virus and some basics lets us come up with some reasonable recommendations.

This is…

  • A virus that is highly tolerant of environmental effects, disinfectants and other things that kill most viruses.
  • A virus that’s shed in potentially massive amounts in feces of sick animals, but also potentially by some healthy animals.
  • A disease that can be fatal.
  • A disease that we have effective vaccines against.
  • A disease that is really only of relevant concern for unvaccinated (or inadequately vaccinated dogs).

There’s definitely cause for concern if a puppy with parvo infection has passed diarrhea outside. We can assume there’s lots of virus there, and that the virus is going to be able to stick around for some time. We don’t know how long, and it would vary with environmental conditions (temperature, pH of the area, humidity, sunlight…), but it’s safe to assume that it’s a fairly long time in most situations.

So, what do we do?

  • Disinfection of outdoor surfaces is pretty futile. Disinfectants don’t work well in the presence of organic debris (dirt) so pouring disinfectants on grass or gravel will not likely do much (except put a lot of disinfectant residue into the environment). Unless it’s happened on a surface like concrete or asphalt (both of which can still be hard to adequately disinfect because they are porous), leave the bleach bottle in the cupboard.
  • Removing feces is a good first step. That would remove the vast majority of virus that has been passed. This might require using a shovel to get some of the diarrhea-soaked grass or soil, but removing as much of the visible contamination as possible is a key step.
  • Restricting access to the area can’t hurt, when it’s feasible. That doesn’t mean cordoning it off and keeping everyone away is needed. The key is to keep young unvaccinated (or incompletely vaccinated) dogs (and dogs that have contact with those dogs) away from the area.
  • Raking the site can help turn over the substrate and get more exposure to UV light. Sunlight is our best outdoor disinfectant and raking can help exposure virus particles that are hidden away.

As always, prevention is better than cure. Preventing these situations is ideal, but admittedly not always possible. Things that can help include,

  • Making sure all puppies are properly vaccinated.
  • Keeping unvaccinated puppies away from high traffic areas.
  • Keeping sick animals away from public areas.
  • Promptly picking up feces from any dog, healthy or not.

More bad news on the MRSP front

Well, "news" perhaps isn’t the best description since we’ve been seeing it for a while, but a paper in an upcoming edition of the Journal of Clinical Microbiology (Gold et al. 2014) entitled "Amikacin resistance in Staphylococcus pseudintermedius isolated from dogs" provides published support for the trend we’ve been seeing.

Staphylococcus pseudintermedius is an important cause of infections in dogs, and a resistant form, MRSP (methicillin-resistant Staph pseud) is a major problem. MRSP also does a great job of becoming resistant to additional antibiotics, usually by picking up resistance genes from other bacteria. We’ve rapidly lost most of our typical antibiotic treatment options for many MRSP strains, and are left with only a couple of viable drugs. One of those is amikacin, an antibiotic we try not to use when we don’t have to because it has to be injected, and because it can be hard on the kidneys. However, it’s literally a lifesaver in some cases.

Over the past year or two (unsurprisingly, really), we’ve been seeing some amikacin resistance in MRSP strains. I say that’s unsurprising because, with bacteria in general (and MRSP in particular), we’re trapped in a game of "use it and lose it." Any time we use an antibiotic, there is some potential for resistance to develop.

The study by Gold et al looked at 422 Staph pseud from dogs, and found that MRSP were significantly more likely to be amikacin resistant, with a rather astounding 37% amikacin resistance rate in their MRSP collection. Amikacin-resistant strains were also more likely to be resistant to a range of other antibiotics, regardless of their methicillin-resistance.

What do we do?

Tough question. Bacteria eventually seem to outsmart us most of the time (or we seem to "out-dumb" them, since it’s often our poor use of antibiotics that leads to problems).

So, what can be done?

Prevention is better than cure: MRSP infections are almost invariably secondary problems. Preventing or limiting underlying disease (e.g. controlling allergic skin disease) can greatly reduce the number of infections and the amount of antibiotics used to treat them.

Infection control: MRSP surgical site infections are increasingly common, and using good infection control practices should help limit them.

Use them right: Making sure drugs are given as prescribed with proper dosing (amount and frequency), and limiting the use of the few remaining MRSP treatment options for cases that really need them are important.

Antibiotic alternatives: Antibiotics aren’t always needed to treat infections. Topical therapy with things like chlorhexidine shampoo can be highly effective for skin infections, and can save antibiotics for infections that can't be treated otherwise.

Will these steps stop the scourge of antibiotic resistance?

No. But they might buy us some more time to figure out how to better handle this and to save some of our limited remaining antibiotic options.

Never a simple story: West Nile in California

Orange County CA is currently experiencing a major outbreak of West Nile infection in people. Since January 94 cases have been confirmed, three of which were fatal, representing nearly a quarter of the 400 cases reported across the country so far this year. The number of cases of infection with a mosquito-borne virus like West Nile (or EEE, which we’ve been seeing over the last month in Ontario horses) can be affected by a lot of factors, including climate/weather, flooding or drought, bird populations and movements, mosquito populations and local mosquito species, and population density of those affected, be they people or animals.

Often we associated wet weather and flooding with increased incidence of diseases like West Nile, but this year California is experiencing a drought. How does that make sense? It’s been suggested that the dry weather is driving birds into more populated areas to look for water. More infected birds in the area provides more opportunity for mosquitoes to bite the birds and then transmit the virus to a person. The number of mosquito pools testing positive in Orange County (80%) is the highest its been since West Nile first hit California a decade ago, and 6.5 times more dead birds (260 total) have tested positive for WNV compared to 2013.

Most of the human cases in California included some signs of illness. When you consider that 80% of people infected with WNV show no signs of the disease, that means there has actually been an even larger number of people actually infected.

The impact on the local horse population has not been mentioned, but it is unlikely that horses will escape this outbreak unscathed. After a relatively slow year for WNV in 2013, I wonder how many horse owners in the area may have decided to forgo vaccinating their horses this year, and may now be regretting it. It’s easy for us to get complacent about infection control when things are going well. In the case of West Nile, people may stop taking precautions to avoid mosquitoes, to remove standing water from their property, and vaccinating their horses. It’s important to remain vigilant though, because there are so many different factors involved in the cycles of various diseases that predicting their resurgence can be extremely difficult, if not impossible. Taking some simple preventative steps, and making basic infection control practices habit can help reduce the impact of unexpected outbreaks, and help keep everyone (people and animals) healthier and safer.
 

Cry me a river...crackdown on Angels' Eyes

Finally.

While having nothing to do with my previous rants on the topic, the FDA has issued warning letters to the manufacturers of Angels' Eyes and similar products that are vaguely disguised antibiotics sold for purely cosmetic reasons, and without a veterinary prescription. These products have been widely available to decrease tear staining (hardly a life-threatening problem) in dogs, fully at odds with any concepts of prudent antibiotic use.

Here’s some of the FDA letter text:

We have determined that your tear stain remover products containing tylosin tartrate are intended for use in the mitigation, treatment, or prevention of disease in animals, and/or to affect the structure or function of the body of animals, which makes them drugs under section 201(g)(1) of the Federal Food, Drug, and Cosmetic Act (the FD&C Act) [21 U.S.C. § 321(g)(1)]. Statements on your labeling, including your website and product labels, that establish these intended uses of your products include, but are not limited to, the following:

• "The active ingredient in Angels' Eyes®, Tylosin as Tartrate, will prevent your dog from contracting Ptyrosporin (Red Yeast) and bacterial infections which causes excess tearing and staining."

• "May help keep tear stains away by reducing oxidation released through tear ducts."

• "Angels' Eyes® is the first product specifically developed for BOTH DOGS & CATS to help eliminate unsightly tear stains from the inside out!"

• "Only ANGELS' EYES® helps give your pets tear stain free eyes and bright coats."

In addition, your tear stain remover products containing tylosin tartrate are new animal drugs, as defined by section 201(v) of the FD&C Act, [21 U.S.C. § 321(v)], because they are not generally recognized among experts qualified by scientific training and experience to evaluate the safety and effectiveness of animal drugs, as safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling. You are using Tylovet Soluble (tylosin tartrate) as an ingredient in the formulation of your product. Although Tylovet Soluble
is an approved drug, your use of Tylovet Soluble in your product is not a use covered by its approved application, and your products are not the subject of an approved new animal drug application, conditionally approved new animal drug application, or index listing under sections 512, 571, and 572 of the FD&C Act [21 U.S.C. §§ 360b, 360ccc, and 360ccc-1]. Therefore, the products are unsafe within the meaning of section 512(a) of the FD&C Act, [21 U.S.C. § 360b(a)], and adulterated under section 501(a)(5) of the FD&C Act [21 U.S.C. § 351(a)(5)]. Introduction of an adulterated drug into interstate commerce is prohibited under section 301(a) of the FD&C Act [21 U.S.C. § 331(a)].

We acknowledge the receipt of three written responses submitted after the inspection in December 2013. These responses discuss your facility's compliance with the Current Good Manufacturing Practices for Finished Pharmaceuticals (Title 21 Code of Federal Regulations Part 211 ). However, your responses do not adequately address our concerns regarding the approval status of your products and your use of tylosin tartrate in those products, as discussed above.

Failure to promptly correct the violations specified above may result in enforcement action without further notice. Enforcement action may include seizure of violative products and/or injunction against the manufacturers and distributors of violative products. “

Interestingly, there’s no mention of anything on the Angels' Eyes website. It will be interesting to see what happens, but it’s great to see some attention paid to this completely illogical use of antibiotics. Hopefully the FDA follows through with this and doesn’t leave it at the warning letter stage.

How to fix an iPad

Sorry… nothing to do with zoonotic diseases, but still entertaining. Our two iPads stopped working over one weekend last October. Figuring they were destined for recycling, I came across some internet posts that said “whack it.” I figured that I had nothing to lose and if nothing else, I’d get the satisfaction of beating on an Apple product. However, it worked. They came back to life with some pretty solid impacts (my knee was sore after) and have needed periodic "re-treatments" since. Lately, one has required a pretty solid thrashing with a rubber mallet, as can be seen in the video.

Casual cat causality

The credit (or blame) for the alliteration goes to colleague and frequent blog material supplier Dr. Stephen Page. It relates to an article in the prestigious medical journal Lancet (Kagihara et al. 2014) entitled “A fatal pasteurella empyema.”

The article describes the case of a 60-year-old man from Honolulu who was admitted to hospital in cardiac arrest. He had various health problems and had had a cough and body aches over the past four weeks, then suddenly deteriorated. He was resuscitated and fluid was found in his chest cavity. When they collected a sample of the fluid, it was full of bacteria that were subsequently identified as Pasteurella multocida. Unfortunately, he died shortly after admission.

Pasteurella multocida is a bacterium that can be found in many animal species but is classically associated with cats. It can be found in most (if not all) healthy cats, as well as in large percentages of other species such as dogs and rabbits. It’s an uncommon cause of infection in people, and is most often linked to cat bites or contact of cats with wounds or other breaks in body barriers. However, it can also be carried by people, and cats are certainly not the only source.

Here, the patient cared for several feral cats and they often slept in his bed (which to me, would make them more pets than feral cats, but that’s beside the point). The authors don’t specifically blame the cats, but it’s inferred. However, there was no investigation (for logical reasons, since it wouldn’t change anything).

Was the cat the source?

Probably, but not certainly.

Further, why the infection developed is a bigger, more interesting and more relevant question, since just being in the vicinity with a cat doesn’t mean you’re going to get an infection.

I often get asked about testing cats for Pasteurella multocida. My somewhat flippant (but still accurate) response is “Here’s the test: Does it look like a cat? If so, it’s carrying Pasteurella.” Cheap and highly accurate.

Seriously, though, it’s true. Most cats carry the bacterium so there’s no indication to test for it. If people are worried about Pasteurella infections (which is really uncalled for, since there are many greater risks in life), they should focus on good hygiene practices, bite avoidance and bite/scratch first aid, not determining whether their cat is carrying the bacterium.

Vet clinic infections...who should pay?

The following question was posed to Dr. Patty Khuly in an article she writes for the Miami Herald.

"Our cats had to go to the vet hospital last week to have their teeth cleaned. The procedures went very well and, as predicted, both were back to normal that evening. Unfortunately, two days later they both started sneezing. First Patches and then Stumpy came down with the exact same cold. Patches got better but we had to take Stumpy back to the hospital. We actually had to pay more for his cold than for the teeth cleaning! Shouldn’t the vet have gone easy on us since our cats live safely indoors and they obviously caught the cold there?"

Dr. Khuly provides a good answer that you can find here.

Here’s my take on the subject:

There are two main questions.

1) Did the cats likely get an infection at the clinic?

  • That’s hard to say. Often, it’s straightforward. In a case like this, not so much. It’s possible the cats picked up a respiratory virus in the clinic from another cat that was sick, or from a healthy carrier. However, it’s also possible (and maybe more likely) that the cats had a recurrence of an underlying infection (or one did, then spread it to the other in the household).
  • Feline herpesvirus is a common cause of upper respiratory tract disease in cats, and a large percentage of cats are infected when they are young. Herpesviruses often live dormant in the body after infections and can reactivate at any point, causing disease. Cold sores in people are caused by a human herpesvirus, and they behave this way too. Stress is a major cause of re-activation, and the stress of hospitalization, anesthesia and the procedure could easily have lead to recrudescence of herpevirus infection in these cats.

2) Did the clinic provide the required standard of care to reduce the risk of hospital-associated infection?

  • Even if the cats acquired an infection at the clinic, it’s not necessarily the clinic’s ‘fault’, particularly if the infection came from a healthy cat that was shedding a virus, unbeknownst to anyone who would look at it. Infection is an inherent risk of hospitalization, and clinics have a duty to take reasonable measures to reduce the risk of disease transmission. That’s a bit of a moving target and it’s pretty subjective, but it’s a key point here. If the cat got the infection in the clinic, was it likely because of inadequate practices, such as failure to isolate a cat with respiratory tract disease, poor hygiene practices (e.g. poor handwashing), failure to use routine infection control measures (e.g. use of protective outerwear like a lab coat) and various other basic infection control concepts? If so, then the clinic’s liable (and should pay for the infection). If not, then it’s an unfortunate event but one that’s no one’s fault.
  • We can’t prevent all infections, but we have a duty to try to prevent as many infections as possible. If the clinic had a reasonable infection control program, had this documented, and followed their policies, they’re unlikely to be liable. Beyond providing optimal patient care, this is why vet clinics need to improve infection control practices. Too often, infection control programs are very informal, undocumented and weak, creating risks to patients and staff, and creating liability risks for the clinic. It leaves the door open for someone to claim that a hospital-acquired infection occurred, and makes it hard for the clinic to convince anyone that the infection was non-preventable.

So, was it the clinic’s fault? I don’t know, and it’s hard to prove. It probably wasn’t, but only with a good infection control program could they state with confidence that they did their best to the prevent infection.

EEE alert, Ontario

The Ontario Ministry of Agriculture Food and Rural Affairs (OMAFRA) has issued an Equine Health Advisory in response to diagnosis of Eastern Equine Encephalitis (EEE) in a horse in Stormont/Dundas/Glengarry, in eastern Ontario. The 12-year-old gelding died, which is the typically outcome with this disease in horses.

EEE is a devastating but fortunately rare (at least in Ontario) disease of horses, people and an assortment of other species (including emus, llamas and alpacas). Typically, a few equine cases are identified in Ontario every year, with human cases being rarer. However, since people and horses are infected in the same way - by the bite of an infected mosquito - finding the disease in a horse indicates risk to both horses and humans in the region.

More information about EEE cases in North America can be found at WormsAndGermsMap.  Information for horse owners in Ontario, as well as Ontario-only equine neurological disease cases, can be found on the OMAFRA website.

FDA releases 2011 antimicrobial resistance data

The US Food and Drug Administration has released the 2011 NARMS (National Antimicrobial Resistances Monitoring System) executive report. It's a good-news/bad-news outcome, which may be as good as can be expected, but at least there's some good news.

Here are some areas that were highlighted by the FDA.

  • Eighty-five percent of non-typhoidal Salmonella collected from humans had no resistance to any of the antibiotics tested.
  • In people, the five-drug resistance pattern “ACSSuT” (resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline) in Salmonella Typhimurium has declined to 19.5% in 2011, from its peak in 1997 at 35.1%.
  • During its 16-year history, NARMS has found Salmonella resistance to ciprofloxacin, one of the most common antibiotics to treat Salmonella infections in humans, to be very low (less than 0.5% in humans, less than 3% in retail meat, and less than 1% in animals at slaughter).
  • Multi-drug resistance in Salmonella from humans, slaughtered chickens and slaughtered swine was the lowest since NARMS testing began. However, multi-drug resistance in Salmonella from retail poultry meats generally increased, with slight fluctuations.
  • Erythromycin resistance in Campylobacter jejuni (C. jejuni) has remained at less than 4% in isolates obtained from humans, retail chicken and slaughtered chicken since testing began. The antibiotic erythromycin is the drug of choice for treating Campylobacter infections, more than 90% of which are caused by C. jejuni.
  • Campylobacter resistance to ciprofloxacin has increased slightly in isolates from humans since 2005. Ciprofloxacin is not approved for use in poultry, and the FDA withdrew approval for the use of enrofloxacin in poultry in 2005. Ciprofloxacin and enrofloxacin are both in the same class of drugs (fluoroquinolones).
  • Resistance to third-generation cephalosporins, another important drug class for the treatment of Salmonella infections, rose among isolates from retail ground turkey between 2008 and 2011, and among certain Salmonella serotypes in cattle between 2009 and 2011. In April 2012, FDA prohibited certain uses of cephalosporin drugs in cattle, swine, chickens, and turkeys. NARMS will continue to monitor these trends over time.

(click image for source)