People like to talk about the "one medicine" concept. It's a great concept, but my big issue with it is there's a lot of talk but not a lot of action.
One way of thinking about "one medicine" in terms of people and pets is to focus on the health of the entire household as a whole, because:
- People can transmit infections to pets.
- Pets can transmit infections to people.
- People and pets can be infected from the same source.
- Infection in a pet or person may indicate that others in the household are also at risk.
It's a complex dynamic. When I speak about this topic, I use a couple of different ways to make the point. One is the concept that we are not a population of people living with dogs, cats, horses etc. - we are a population of animals. Similarly, I sometimes say "pets are people too, at least microbiologically." What I'm saying is that we can't focus just on humans or just on pets. The household as a whole needs to be considered, and care of the health of the all of its members - human and animal - needs to considered together.
What does that really mean?
Physicians need to be aware of the presence of pets in the household and other animal contacts. This information might be important when considering certain diseases. For example, if someone comes to their physician with flu-like symptoms and their physician knows they have pet birds (especially psittacines), then the physician would hopefully consider psittacosis. This disease is caused by Chlamydophila psittaci, a bacterium that can be carried by healthy birds. Not realizing there is a bird in the household can lead to a missed diagnosis.
Veterinarians need to be aware of the health status of people in the household. People with close contact with the human healthcare system and people with compromised immune systems are more likely to be carrying certain infectious agents. They are also more likely to pass these pathogens on to their pets. Therefore, knowing the health status of the owner might lead the veterinarian to consider different diseases in the pet, thereby improving diagnosis. Conversely, people with compromised immune systems are at increased risk for various infectious diseases from pets. If the veterinarian knows a pet owner is at increased risk, they can provide better advice about disease prevention measures to protect the owner. Veterinarians rarely ask owners about their immune status, including pregnancy (even the "how far along are you?" question is dangerous, because eventually you're going to get the "I'm not pregnant!" response.) Ideally, people should have a positive, comfortable relationship with their veterinarian, realize that their veterinarian is a member of their (and their family's) overall healthcare team, and therefore tell their veterinarian about any relevant health issues. For this to work, they need to understand the value of this communication, trust their veterinarian and know that their personal details will be kept confidential. At the same time, the veterinarian needs to understand the issues and need for such information, and have a plan on how to use it.
Veterinarians and physicians need to communicate better. They need to know who to contact when necessary and be able to do it efficiently. This is also relevant for non-infectious disease issues. For example, there could be a situation where a veterinarian has had to euthanize a pet: the veterinarian may realize that the owner is quite distraught, but can't do much beyond offering condolences and providing contact information for resources to help them out. The physician may not know anything about the situation, but it could be of significant relevance to the person's health. If nothing else, the physician could be notified that there's a potential concern. There are privacy issues that need to be considered and sorted out, but a little conversation can go a long way. The ability of veterinarians and physicians to contact each other about relevant issues can help prevent problems with miscommunication, provide general information about certain topics and help provide optimal patient care.
One medicine needs to be one medicine in action, not just in theory.
There is a degree of risk of disease transmission from any contact with an animal, just as there is from any contact with another person. Some of the diseases involved are minor or even insignificant, while others are potentially devastating. And the risk can change in certain situations, such as pregnancy. A developing fetus is more susceptible to some diseases that may typically have little to no effect on an adult. Toxoplasmosis is one disease that gets a lot of attention from pregnant women.
Toxoplasmosis is caused by the protozoal parasite Toxoplasma gondii. Infection of a pregnant woman with Toxoplasma can cause birth defects or even miscarriage. But the real risk occurs when a woman who has not been previously exposed to Toxoplasma becomes infected during pregnancy. Pregnant women who were exposed to Toxoplamsa before they became pregnant, and therefore already have antibodies against the parasite, are not at risk.
Cats are the only animal species that can spread Toxoplasma in their stool. Only a very small percentage of cats are shedding Toxoplasma at any one time, but the proportion can be higher among cats that go outside, hunt or are fed raw meat. It takes 24 hours or more for Toxoplasma in cat stool to become infectious - a person cannot be infected with Toxoplasma from fresh stool. This key point can greatly reduce the risk of transmission from a cat, if the cat's litter box is cleaned out on a daily basis.
Any infection that can potentially have devastating effects on a fetus needs to be taken seriously. While it appears to be rare these days, some women are still advised to get rid of their cats if they are pregnant. Pregnant women do not need to give up their cats! A few basic measures can greatly reduce the risk of transmission of Toxoplasma from cats to pregnant women:
- Pregnant women should not have contact with litter boxes (or any cat feces) if possible - preferably another person should do the litter box cleaning.
- If a pregnant woman must clean the litter box, it should be done daily so that Toxoplasma does not have enough time to become infectious.
- Litter boxes should be regularly scrubbed and cleaned with scalding water (see the Worms & Germs Resources page for more information on Litter Boxes).
- Keep your cat's fur free of stool contamination. This is especially important in longhaired cats that might get stool on the fur around their hind end, or sick/old/obese cats that have difficulty grooming themselves properly.
- Keep your cat indoors. Outdoor cats are more likely to be exposed to Toxoplasma and spread the infection.
- Do not feed your cat raw meat.
- Wash your hands thoroughly after cleaning the litter box, handling raw fruit and vegetables, and working with soil (for example, in the garden).
- Cook all meat completely to recommended temperatures, and practice safe meat handling to prevent spread of contamination from raw meat to kitchen surfaces and other food.
More information about Toxoplasma and zoonotic diesases associated with Cats can be found on the Woms & Germs Resources page.