Fever, chills, cough, headache, muscle aches… sounds like an obvious case of the flu, doesn’t it? But: Recently, I learned about a masquerader called Q fever, which causes symptoms so similar that even doctors often mistake it for the flu.

Therein lies the danger. Although Q fever is easy to cure if properly diagnosed early on, left untreated it can lead to pneumonia, heart damage, hepatitis or even death. And here’s a scary fact — you can catch it from your dog or cat, even if your pet seems perfectly healthy.

You’ve never heard of Q fever? Neither had I. And neither have many doctors… so you may need to bring up the subject with your physician if you ever develop possible symptoms of the disease.

Thankfully, Q fever is rare — though no one knows just how rare because it is underreported, I was told by infectious disease specialist Edward A. Dominguez, MD, of Methodist Dallas Medical Center. Here’s how to protect yourself…

JUST WHAT IS IT?

Q fever was first reported in Australia in the 1930s. The Q stands for query, because nobody knew what the disease was or how to treat it.

Unlike flu, which is caused by influenza viruses, Q fever is caused by a germ called Coxiella burnetii. “It’s not a bacterium, virus or fungus. Instead, it is a rickettsia, an infectious parasitic microorganism similar to those that cause typhus or Rocky Mountain spotted fever,” Dr. Dominguez said.

Q fever is a zoonotic infection, meaning that people get it through contact with infected animals, such as horses, goats, cows, sheep, rabbits, cats and dogs. People most likely to be exposed are veterinarians, breeders, ranchers and others who work with animals, but pet owners may be at risk, too.

The likelihood of transmission is highest when an infected animal gives birth or is killed. (Dr. Dominguez recalled a group of poker players who all contracted Q fever after an infected cat gave birth in the same room.) The disease most often is caught when a person inhales air contaminated with this type of rickettsia, so poorly ventilated or enclosed spaces (small rooms, sheds) pose a greater risk than outdoor areas. But Q fever also can be transmitted through food if a person drinks milk or eats meat from an infected animal.

WHY AND HOW TO GET HELP

About half of people who get infected develop no symptoms and experience no short-term or long-term problems. For the other half, symptoms typically develop within three weeks after exposure and last one to two weeks. Warning signs of acute infection: High fever (up to 104° or 105°!)… chills and/or sweats… severe headache, joint and muscle aches… sore throat, cough, chest pain… nausea, vomiting, diarrhea and abdominal pain. According to the Centers for Disease Control and Prevention (CDC), 30% to 50% of patients with a symptomatic infection develop pneumonia… and in 1% to 2% of acute cases, the disease is fatal.

Long-term danger: When the acute form of the disease does not get successfully treated or clear up on its own, patients may develop chronic Q fever. Serious complications can include hepatitis, an inflammatory condition of the liver, and endocarditis, inflammation of the heart lining and/or valves. For chronic Q fever patients, the CDC reports a death rate as high as 65%.

I asked Dr. Dominguez whether people who recover from acute Q fever might later develop the chronic form. He said, “If recovery was induced by antibiotics, no. If the infection went away on its own, chronic infection is unlikely — but not impossible.”

Self-defense: Of course you must see your doctor if you have symptoms that suggest Q fever. But: Since physicians often do not recognize Q fever in patients with flulike symptoms, Dr. Dominguez said, you also should tell your doctor about any recent animal exposure and ask, “Could this be Q fever?”… request blood tests to check for antibodies to the rickettsia and other evidence of Q fever’s effects on the body, such as thrombocytopenia (reduced blood platelets), electrolyte imbalances and abnormal liver function… and ask for a chest X-ray to check for pneumonia.

When acute Q fever is caught early, it generally responds well to a 15- to 21-day course of oral tetracycline antibiotics (since the rickettsia, like bacteria, is vulnerable to antibiotics). Sulfa drugs or quinolone antibiotics also can help. Note: If your doctor does not prescribe antibiotics because your initial blood test for Q fever was negative, yet you still feel ill two weeks later, ask to be retested. It can take several weeks for antibodies to build up to detectable levels.

Chronic Q fever may require daily intravenous antibiotics for eight weeks or longer. If the infection causes heart valve damage, valve replacement surgery may be necessary.

Prevention pointers: The Q fever vaccine used in other countries is not approved in the US because it can trigger a severe skin reaction if the rickettsia is already present. Research is under way for a better vaccine, but for now the best bet is to minimize your risk of exposure to Q fever. Dr. Dominguez’s advice…

  • Stay outdoors or in well-ventilated areas when around farm animals.
  • Do not drink unpasteurized milk or eat raw meat.
  • To reduce your pet’s risk of being infected with the rickettsia (and thus reduce your risk of catching it from your pet), limit your pet’s exposure to animals who live on farms, on ranches or in the wild. It also is a good idea to get a veterinary evaluation for your pet, especially if it is pregnant.