Q-fever

Coxiella Burnetii

Dr. Hani MasaadehMD PhD

ORGANISM Coxiella burnetii is a small pleomorphic Gram-

negative bacterium that originally was classified among the Rickettsiaceae.

C. burnetii proliferates intracellularly in an acidic vacuole (phagolysosome). The organism can survive for a long time as a spore in very unfavourable conditions.

Q fever is a zoonotic disease caused by Coxiella burnetii

Signs and Symptoms in Humans  Q fever begin with sudden onset of one or

more of the following: high fevers , severe headache, general malaise, myalgia, confusion, sore throat, chills, sweats, non-productive cough, nausea, vomiting, diarrhea, abdominal pain, and chest pain.

Q-fever: Coxiella burnetii

Obligate intracellular rickettsia Highly infectious - one organism may

cause disease Found worldwide Reservoir = animals Hardy organism

Q-fever: Reservoir Species Goats, sheep and cattle:

• No obvious illness in animals

• Can cause abortions Cats Rabbits Birds Rodents ????

Q-fever: Transmission to Humans

Organism is excreted in urine, feces, milk, and especially in birth fluids

Humans are usually infected by inhalation of the organism from contaminated environments

Occasionally raw milk

Potential Sources of Infection

Contaminated wool Soiled laundry Livestock trucks Livestock Air conditioner ducts in common with

animal quarters Contaminated airborne dust particles

Q-fever

High concentrations in animal tissues, especially placenta

Survives for long periods in environment

Highly resistant to physical and chemical agents

Q-fever: Risk Factors

Direct contact with infected animals Farmers Veterinarians Slaughterhouse workers Sheep researchers

Q Fever: Human Illness

Incubation period is 20 days (14 - 39 days)

Symptoms may include headache, weakness, malaise, chills, severe sweats, retro-orbital pain

Pneumonia Abnormal liver function tests Granulomatous hepatitis

Q Fever: Human Illness

Self-limited febrile illness of 2-14 days Chronic Q fever

• endocarditis results in less than 1% of Q fever cases

• Endocarditis may develop in 1 to several years after infection

Osteomyelitis and/or neurologic manifestations are also possible

TREATMENT The aim of treatment is different in acute and

chronic Q fever. In acute infection, bacteriostatic treatment will

usually suffice for a clinical cure. Doxycycline is a good choice here .

In chronic Q fever treatment with doxycycline, ciprofloxacin and rifampicin should preferably be given for a long period (1-3 years).

Preventive Measures

Education of high risk individuals• restrict access to birthing areas

• disposal of birth products

Pasteurization of milk Currently, no commercially available

vaccine in the United States Surveillance in researchers who work

with sheep

TAKE HOME

Zoonoses are common

Non-specific symptoms

Diagnostic tests difficult to interpret

Ask about risk factors