Beware of the Capnocytophaga canimorsus infection

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Introduction

Having a dog certainly has many benefits for your health. According to a study conducted in 1980 at the University of Pennsylvania, playing with a dog, almost immediately, lowers blood pressure, decreases heart rate, and helps relax muscle tension.

Unfortunately, those lovely pets can carry many dangerous pathogens that might endanger your life if you don’t take proper precautions.

In this article, you will learn everything you need to know about a very dangerous germ called “Capnocytophaga canimorsus”!

What is Capnocytophaga canimorsus?

Capnocytophaga canimorsus is a bacterium found in the saliva of some dogs and cats. It spreads mainly through dog and cat bites and scratches but can also be transmitted by direct contact of open wounds with dog’s or cat’s saliva through licks.

This germ has been implicated in many disorders in humans with immune deficiency including sepsis (an infection causing the inflammation of the whole body), meningitis, and other circulatory and hearth-related affections.

Also, people on prolonged medication such as steroids or people with cancer present a high risk of developing that illness.

What are the signs of Capnocytophaga Infection?

People who get infected with Capnocytophaga canimorsus may manifest a variety of symptoms, many of which are common to lots of illnesses, making it more difficult to diagnose:

• Swelling around the bite wound (within hours)
• Redness, pain, and pus draining
• Fever
• Diarrhea,
• Vomiting
• Stomachache
• Headache
• Muscle soreness or joint pain
• Hypotension
• Dermatologic lesions (erythema; petechia and popular eruption)

Can you have a Capnocytophaga canimorsus infection and not know it?

Yes indeed, you can have Capnocytophaga infection without noticing it, at least during the incubation period.

According to the CDC: The symptoms described in the previous paragraph will show within 3 to 5 days in most cases, but wider ranges have been described (1-14 days).

A capnocytophaga infection can be very serious and life-threatening causing complications such as heart attack, multiple organ failures, or even sepsis and gangrene (people may need amputations of fingers, toes, or even whole limbs).

Death occurs in 30% of people who develop a severe infection. And can be as quick as 24 hours after the bite.

How is Capnocytophaga infection diagnosed?

The primary way to diagnose Capnocytophaga infection is by performing cultures of the infected tissue (in case of sepsis, a blood culture is performed).

However, Capnocytophaga canimorsus infection may not be easily detected as it requires special culture conditions to grow in the laboratory (lots of iron and high carbon dioxide levels). Therefore, specific testing should be requested by the physician who needs to be aware of this disease and pay attention to the patient’s risk factors and eventual animal exposure.

Usually, the treatment is started before confirmation of the diagnosis due to the severity of the infection.

Sometimes, a basic blood smear can help detect this bacterium. Although this test is not specific to Capnocytophaga, it is much faster than normal cultures.

Molecular tests such as PCR for Capnocytophaga are not yet broadly available.

Am I at risk of developing Capnocytophaga Infection?

Anyone could get infected with Capnocytophaga canimorsus if this pathogen finds its way into his bloodstream. Yet, the severity of the infection will vary depending on the immune system of the contaminated person.

Many factors increase the risk of infection, such as:

• Abuse drinking alcohol.
• Have had a splenectomy (surgical removal of the spleen).
• Have a disease that weakens the immune system, such as:
  • Diabetes
  • Cancer
  • AIDS
• Are taking chemotherapy sessions
• Have a transplant.

In general, the category of people who are most likely to develop this disease is what we call YOPI (Young; Old; Pregnant, and Immunodeficient).

So, what can you do if you get infected with Capnocytophaga canimorsus? Is there a specific treatment?

What is the treatment for Capnocytophaga Infection?

This pathogen is quite susceptible to many antibiotics. But it seems that a penicillin/beta-lactamase combination or a large spectrum cephalosporin is the drug of choice for intravenous medication.

Although most physicians would administer a large spectrum of medication before having the results of the diagnosis test (which may take up to a week), It would be interesting to perform an antibiogram in order to determine the right antibiotic for the bacterium causing the infection, as there is more antibiotic resistance lately.

You may need an association of 2 or more antibiotics to help you fight the infection and get better.

If you have been bitten or scratched by a dog or a cat or have any reason to believe that you might be infected with Capnocytophaga canimorsus, you must call your doctor immediately and let him know about the circumstances of your infection and your contact with animals.

How to prevent yourself from getting infected with Capnocytophaga canimorsus?

When it comes to prevention from Capnocytophaga canimorsus infection, 4 major guidelines are to be met:

• Avoid being bitten or scratched by your dog or cat
• Avoid being licked on your face or any other body part with an open wound
• Always keep good hygiene before and after contact with your pet
• Have your pet regularly checked by your veterinarian and also keep his vaccination up to date.

Your dog needs proper training. It is preferable to start teaching him, at an early age, how to behave around kids and stay calm and playful.

If you notice any access of aggressivity or violence in your dog or feel like you can’t handle his dressage by yourself, you’ll probably need to consult with your veterinarian or have a renowned dog trainer adjust his behavior for you.

Check out this article to know more about dog behavior and personality.

You also need to get your children used to being around pets and treat them gently and avoid harming them as this may result in an aggressive reaction from your pet.

If a dog or a cat bites/scratches you, you must wash the site of the bite/scratch, immediately. And go visit your doctor as quickly as possible, even though, you don’t show any signs of infection.

Conclusion

Dogs and cats have many germs in their mouths as normal oral flora. Those germs do not necessarily make your animal sick, but some of them occur to be pathogenic to humans and may cause serious health conditions such as Capnocytophaga infection, rabies, and many other zoonoses (diseases that transmit from animal to humans and vice-versa).

Even though Capnocytophaga infection is very rare and, mainly, affects people with a compromised immune system, you should always take precautions, and get used to good hygiene practices. As it is the only way to, effectively, protect yourself and your family from life-threatening diseases.

Resources

• Gaastra W, Lipman LJ. Capnocytophaga canimorsus. Vet Microbiol. 2010 Jan 27;140(3-4):339-46.
• https://www.wormsandgermsblog.com/files/2008/04/M1-Capnocytophaga.pdf
• J. Michael Janda, in Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases (Eighth Edition), 2015
• Lorry G. Rubin, in Principles and Practice of Pediatric Infectious Diseases (Fifth Edition), 2018
• Janda JM, Graves MH, Lindquist D, Probert WS. Diagnosing Capnocytophaga canimorsus infections. Emerg Infect Dis. 2006 Feb;12(2):340-2.
• https://www.cdc.gov/capnocytophaga/

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