Yesterday, I received a bulk email ad advertising a book about Chinese herbal medicine in pets.One of the introductory statements said that Chinese medicine is "becoming more popular as people realize the powerful yet gentle ways of TCM healing." On the same day, I received a Morbidity and Mortality Weekly Reports article entitled "Hepatitis temporally associated with an herbal supplement containing artemisinin."

Also known as qinghaosu, artemisinins are a class of compounds (drugs) that are used for the treatment of malaria. They are the active constituents of the herb Artemisia annua (sweet wormwood). Herbal supplements containing these compounds are marketed for "general health maintenance" (whatever that means), treatment of parasites and treatment of cancer.

In the MMWR case report, the CDC was notified about a person who developed hepatitis while taking an herbal supplement containing artemisinin. The person was prescribed the supplement by a naturopathic practitioner who attributed the patient’s chronic abdominal pain to a parasitic infection. Six weeks of treatment was prescribed but 1 week into treatment, signs of hepatitis developed. No other causes of hepatitis were identified, and it resolved after the person stopped taking the supplement. That doesn’t prove the supplement was the cause, but it is suspicious.

The supplement was tested and it had the amount of artemisinin that the label claimed. Artemisinin is generally considered a safe treatment for malaria, however the prescribed dose was much higher than the dose that is conventionally used for malaria treatment. It’s unclear whether the liver damage occurred because of the dose, interactions with other compounds in the supplement, or an unusual reaction in this patient.

It’s important to remember that herbal therapies are drugs. The fact that they are still in their natural state does not necessarily mean they are safer. In fact, there can be increased risks because of inconsistency in potency, dose and the presence of other compounds. With conventional drugs, extensive testing is done before they are released, to reduce the risk of them making people sick. With alternative therapies, the opposite occurs. There is no mandated pre-release testing so harmful products are only identified after they make a lot of people or animals sick.

A drug is a drug, whether it comes in a pill, liquid or leaf form.

Animal bites are very common. Millions of people are bitten every year, and the resulting burden in terms of pain, infection and financial costs is astounding. Dog bites get the most press because they often cause significant trauma. Dogs have larger and stronger mouths, and can bite repeatedly and more aggressively in some attacks. Deaths attributed directly to pet bites pretty much exclusively involve dogs.

Cat bites are smaller and have less chance of causing significant injury to tissues, but they may be more severe in the long run. There’s a scientific paper called “Cat bite infections: biological warfare amongst cats,” which is a testament to the nasty populations of bacteria that live in cats’ mouths. It’s not just the presence of bacteria that’s a problem (afterall, dogs’ mouths are full of potentially nasty bacteria as well) – the nature of cat teeth and the resulting bite wounds is a major factor. Cat bites often result in small but deep puncture wounds. This pushes bacteria deep into the tissues, where they’re harder to get rid of and which results in a much greater chance of causing an infection. Furthermore, cats tend to bite areas that are high risk for development of bad infections, especially hands, which have a complex and susceptible network of tendons, tendon sheaths, joints and nerves. Bites that appear to be minor can end up causing serious problems, often much worse that an initially more dramatic dog bite.

Really, you don’t want to be bitten by either a dog or a cat (or an iguana, hamster, person or anything else). A large percentage of bites are avoidable, and knowing how to interact with animals and read signals of aggression or fear are critical. If you are bitten, prompt and proper care of bites is required to prevent serious, long-term complications.

More information on bites, including management of bites, is available on the Worms & Germs Resources page. The CDC has a podcast that includes information about bite-avoidance that can be accessed by clicking here.

Four people exposed to horses infected with Hendra virus in Australia are taking an experimental drug to try to prevent or reduce the severity of infection. All are currently healthy, but it is unknown whether the virus is incubating in them and whether disease may develop.  People can be infected with this virus through close contact with infected horses, as was the case with these four individuals. While human infections are rare, 50% of infected people die. Therefore, it’s understandable that they would choose to try an experimental treatment.

These people will be treated for five days with intravenous ribavirin, an antiviral drug. There is evidence that ribavirin can kill Hendra virus in the laboratory, but it’s not known if it actually does anything in infected people. It has some potential adverse effects, but given the severity of disease and high risk that these people have been exposed, it’s certainly a reasonable decision. This treatment was also used in the Hendra virus outbreak in 2008. One person died, one survived after a long stay in ICU, and one did not get sick.  It’s not known whether the drug did anything to help. The death of the treated person doesn’t necessarily mean the treatment is not useful for some people or for certain stages of infection. Hopefully, ribavirin has a better chance of working when infection is only developing, before these people get sick.

This Worms & Germs blog entry was originally posted on equIDblog on 13-Aug-09.

A 74-year-old Colorado woman that had been warned repeatedly not to feed bears was killed by one. The circumstances surrounding the attack are not known, but there was clear evidence of mauling. Wildlife officers had received numerous complaints for at least a decade that the woman was habitually feeding bears.  She was warned several times but never ticketed because of difficulty gathering solid evidence of the illegal activity. Wildlife officers and sheriff’s deputies killed two bears after the attack. It was reported that a necropsy of the larger 394 lbs animal showed that it appeared to have been feeding on a human, but this has not been officially confirmed yet.

As we’ve discussed before, people often feed wildlife thinking they are helping the animals, but the opposite is true. Numerous problems are caused by feeding wildlife, including making animals dependent on people for survival, decreasing animals’ fear of humans, encouraging animal encroachment into urban areas and generally increasing the chance for both human and animal injury and infection.

Hendra virus, a virus that can kill horses and people, has resurfaced in Queensland, Australia. This bat-borne disease has caused periodic fatalities in horses and people that work with horses. The latest outbreak is thought to have killed up to three horses and resulted in the potential exposure of at least 30 people. The likelihood of these people getting sick depends on how close their contact was with the sick horses. Close contact with secretions from infected horses seems to be required to transmit disease. One person reported being snorted on by an infected, dying horse and being "covered" in blood, which is certainly concerning. An outbreak last year killed a veterinarian and hospitalized a veterinary nurse.

The farm in question is under quarantine and people that have been exposed are being monitored. There is no treatment for potentially exposed individuals, so they are in the unenviable position of having to wait and see if they get sick.

A virus like this is very hard to control. It’s lives in fruit bats and only occasionally crosses into horses. The sporadic nature of disease makes it hard to control and predict when cases will occur. The key is early identification so that there is minimal exposure to other horses and people. People also need to take routine infection control precautions. One veterinarian handled an infected horse without using gloves or a face mask, as recommended, because he had left them in the car. Exposure to a potentially fatal infectious disease is not worth the few minutes of time saved by not following recommended precautions.

This Worms & Germs blog entry was originally posted on equIDblog on 10-Aug-09.

State public health officials are trying to get the word out about a potential rabies exposure in Annapolis, Maryland.  A rabid kitten was discovered outside a Sears store at the Westfield Annapolis shopper center. The concern is that people may have handled the kitten and been exposed. It’s a major concern with kittens because they can be hard to resist – a pathetic-looking/cute little kitten sitting around in a public place could easily be picked up by many people. Also, when rabies is found in a young kitten, there are often other rabid kittens from the same litter in the area. Rabid stray kittens have caused widespread exposure in the past, and this case may be no different.

Anyone who recently had contact with a stray kitten in the area in question should contact public health officials as soon as possible. Simply touching the kitten is not a rabies exposure risk, but anyone that has had any contact with a potentially rabid animal should talk to public health officials to determine whether there is any risk of infection and whether post-exposure treatment is required.

While kittens are hard to resist, avoid handling stray kittens. This is especially true if it’s transient handling where you will never know what happened to the kitten afterwards (as opposed to someone adopting a kitten off the street – this is still risky from some standpoints, but at least you know if the kitten gets sick and you can make sure that it is tested for rabies or other other zoontic diseses, if need be).

A house cat in the Eagle, Colorado area has been diagnosed with pneumonic plague. Plague, caused by the bacterium Yersinia pestis, is a disease that still strikes fear into people. While we are long since removed from the period where the "black death" killed a large percentage of the population in Europe, plague still has a foothold is some regions of the world like the southwestern US. It is present in some wildlife (mainly rodents) and periodically infects people or domestic animals through transmission by infected fleas or direct contact.

Plague is periodically identified in cats – it’s almost always outdoor cats that are affected since they have more interaction with wildlife and are at greater risk of flea infestation. Several forms of the disease can occur, including pneumonic, septicemic and bubonic plague. Pneumonic plague is a severe lung infection caused by the plague bacterium which is highly fatal.  This form is of particular concern because infected cats can spread the infection to people through aerosols produced by coughing and sneezing, or through contact with respiratory secretions. People caring for sick cats are at risk of developing plague (especially pneumonic plague, which is almost invariably fatal if untreated). Veterinary personnel are at particularly high risk. One study reported that 20% of people who contracted plague from cats worked in vet clinics. Of these, 25% of them died. 

If you live in an area where plague is present in wildlife, keep your cat indoors, avoid contact with wild rodents, keep wild rodents out of your house and make sure that you have a flea prevention program for you pets. If these things are done, the risk of disease transmission is very low.

Image source: www.northernsun.com

It seems like whenever a hit TV show or movie features an animal, there’s concern about the "101 Dalmatians effect," whereby there’s a mad rush to get the animal for a pet. When 101 Dalmatians was a hit movie, there was a huge spike in sales of this rather unusual breed – a breed which is certainly not for everyone. This results in unqualified breeders and puppy mills churning out marginal or poor quality pets and people getting a pet that really doesn’t suit them. The end result can be a lot of disappointment, heartache and abandoned pets. This pattern has been repeated with various other breeds and animal species, and there is concern that the same will happen with guinea pigs as a result of the new Disney movie G-Force.

In terms of human health, guinea pigs are relatively benign. Bites and scratches are probably the biggest concern, and are often the result of improper handling. Bites can become infected from bacteria in the guinea pig’s mouth or from bacteria on the person’s skin. Allergies are also a potential problem. The number of diseases that are known to be transmitted by them is relatively small, and the risk of disease transmission is rather low.

Lymphocytic choriomeningitis virus (LCMV) is a concern with all rodents. It typically only causes disease in people with compromised immune systems, but can result in fatal infection. The risk of a guinea pig carrying this virus is likely greatest in animals from large rodent breeding facilties and when there is contact with wild rodents.

Ringworm is perhaps the most common infection that people get from guinea pigs (apart from infections following bites). Even healthy guinea pigs can carry the fungus that causes this disease.

Guinea pigs can carry Salmonella, but they are quite susceptible to infection and usually get quite sick. The risk of a healthy guinea pig shedding Salmonella, especially for a prolonged period, is pretty low. The risk is presumably greatest shortly after purchase.

Rabies is always a potential problem in mammals but the risk is very low with small rodents such as guinea pigs. (Very low isn’t zero though, since hamsters have been sources of potential rabies exposure).

There are other potential problems too, but they are all quite rare.

The keys to reducing the risk of infection are:

  • Purchase a guinea pig that looks healthy, is eating well, has no skin lesions or diarrhea, and is active and alert. Ideally, purchase an animal from a local breeder as opposed to a store that might have obtained the animal from a large breeder, via an animal warehouse, hundreds or thousands of miles away.
  • Learn how to properly handle a guinea pig to reduce the risk of bites and scratches, as well as injury to the animal.
  • Keep pet guinea pigs away from wild rodents.
  • Use good general hygiene. Wash your hands after handling the guinea pig and after contact with bedding.
  • Thoroughly wash any bites or scratches.
  • Take particular care in the period shortly after purchase.
  • Even though the cost of the guinea pig is less than the cost of a vet visit, a veterinary examination is important when the animal is sick. Apart from our ethical responsibility to take care of our pets, it’s important to make sure that illness isn’t caused by a disease that can be transmitted to people.

More information about the diseases mentioned above is available on the Worms & Germs Resources page. While we don’t have a specific guinea pig info sheet yet, much of the information on the hamster information sheet also applies to guinea pigs.

A Windsor, Ontario woman is convinced that her dog acquired listeriosis afetr eating recalled hot dogs.  Last week, Maple Leaf Foods recalled various hot dog products because of low-level contamination with the bacterium Listeria monocytogenes, the cause of listeriosis. Her dog Tigger was fed four hot dogs one evening, and the next morning starting vomiting. He recovered after a few days of treatment. No specific testing was done to investigate the possibility of listeriosis.

Dogs can get listeriosis.  Non-specific signs of infection including vomiting, diarrhea and fever are most common. Neurological disease can occur in a small percentage of cases. Listeriosis is extremely rare in dogs, however, despite the fact that dogs are certainly exposed to the bacterium periodically. Just because the dog ate recalled meat and got sick, it does not mean that the dog had listeriosis.

No human illnesses have been reported in association with this recall, and it’s very unlikely that this dog actually had listeriosis. It’s possible but I really doubt it. Dogs get gastrointestinal disease like this all of the time, from a variety of causes. Eating four hot dogs in one night could itself cause diarrhea in some dogs.

Some tips come to mind from this story:

  • Limit feeding of treats to dogs. Four hot dogs is pretty excessive. Low fat, nutritious treats are better.
  • Pay attention to recalls. Don’t eat recalled food or feed it to your pet. At the same time, don’t overreact to recalls. We are exposed to potentially infectious agents on a daily basis, but a combination of our immune system, normal bacterial populations in the intestinal tract, low levels of contamination and other factors mean that we don’t usually get sick. If you are concerned about listeriosis, make sure processed meats are cooked before feeding.
  • If you are really concerned or suspicious about a disease, make sure testing is done.
  • If you think food is the source of a problem, save a sample. It might be useful to test the food.

More information about listeriosis in animals is available in the Worms & Germs archives.

I’m back from a week away with no internet access, so I have some catching up to do. One of the first things I stumbled across on my return was an article in the Guelph Tribune about a summer kids camp at the Guelph Humane Society. At the camp the kids get exposed to various aspects of animal care and welfare, and have field trips to sites like a Donkey Sanctuary and Butterfly Conservatory. Some parts of it sound quite good, but it’s clear that the kids get to have a lot of contact with shelter animals, since playing with the animals is the "highlight of the camp," and as the camp director states "Who wouldn’t want to hang out with cats and dogs all day?"

I have nothing against young kids having contact with pets (being the father of three young kids and the owner of multiple pets). Contact with animals is very rewarding for children, and a program to increase awareness about pets, animal care and the problems with overpopulation could be a great thing. However, I’m not sure that this is the best way. I only have a superficial idea of what happens at this camp based on the article, but I have a few different concerns.

Child safety

  • Any contact between people and pets carries some (albeit very low) risk of infection. Certain things increase the risk. One is young age. Kids are at increased risk of infection. The day camp had children between 5 and 13 years of age – the young end of this range certainly could be considered a high risk group.
  • Another issue is the increased likelihood that animals are shedding infectious agents. Shelter animals are definitely a high risk group, because of factors such as young age, stress, mixing of animals from various sources, illness, and under- (or lack of) vaccination and deworming.
  • The lack of good knowledge of temperament of these animals is another concern, as it’s harder to predict whether an unfamiliar animal might be more likely to bite or scratch. I assume (hope) that the kids are only allowed to have contact with animals that have been assessed in some way, but it’s difficult to know how an animal is going to react in certain situations.
  • Another consideration is the sometimes unpredictable nature of contact that kids have with animals. Young kids don’t inherently know how to interact with strange animals. Even if they act very well around their own pets, they may act differently in a strange situation with animals that act differently, and not know how to detect or respond to signals that the animal is aggressive or afraid.  Education and supervision are important and should be a part of a program, but you can’t instantly eliminate these risks.
  • The humane society environment can also be assumed to be pathogen-rich – there is a high likelihood that various surfaces (e.g. floors, counters) throughout the facility are contaminated with various bacteria, fungi and parasites.
  • Kids could also transfer infectious agents to the household, something that is of greatest concern if there are very young, elderly or immunocompromised individuals present.

Humane society safety

  • Humane societies are at constant risk of infectious diseases, including outbreaks. Outbreaks can cause major problems, including temporary closure, illness in staff or owners of newly adopted animals (e.g. ringworm), or mass euthanasia. Infection control measures can be highly variable in humane societies, and adding a group of kids to the mix certainly doesn’t help. The more contact and movement in a facility, the greater the risk of disease transmission. Strict adherence to careful infection control protocols (which is not often the case, even at the best of times) is required. Good practices at the camp such as careful attention to hygiene, restricting contact with certain groups of animals, and very careful supervision could reduce the risk of disease transmission, but you can never eliminate the added risk that this type of program would bring.

Pet safety

  • Various infectious diseases could be transported home on the bodies of kids or their clothing. Some of these could pose a risk to any pets in the household. Risks are much greater if there are young, old, sick or inadequately vaccinated pets in the house.

I wonder whether the parents of these children were informed (in writing or otherwise) that their kids would be exposed to a increase risk of infectious diseases, bites and scratches, that they should take measures to reduce the risk of disease transmission when the child returns home, and what precautions are being taken at the camp.