Q Fever

Q Fever is caused by Coxiella burnetti. Reservoir – cattle, sheep, goats. Spread – inhalation of aerosolized particles

The organism has antigen variation;

1. Phase 1 antigen- very infectious
2. Phase 2 antigen- non-infectious. e.g., in culture

One bacterium is enough for infection to occur. Antigenic shift- differentiates acute from chronic infection. Incubation- 3 to 4 weeks.

Clinical presentation

1. Acute disease; fever, chills, headache, pneumonia, hepatitis, acute endocarditis

• Maculopapular rash in 20 %

2. Persistent, localized infection;

• Chronic endocarditis
• Bone and joint infection
• Encephalitis
• Vascular infection

Investigations

1. Serology

• Phase1 and 2 IgM titers for acute infection
• Phase 1 and 2 IgG for chronic infection

1. Antiphospholipid antibodies and lupus anticoagulant
2. LFT- elevated transaminases
3. CBC- leukocytosis, thrombocytopenia
4. ESR and creatinine phosphokinase elevation
5. Isotype tests and phase-specific antigens through PCR
6. Culture- identifies the organism

Differential diagnosis

• Pneumonia
• Hepatitis
• Endocarditis
• Osteomyelitis

Management

1. Prompt treatment with doxycycline
2. For endocarditis- prolonged treatment with doxycycline and rifampicin or ciprofloxacin and hydroxychloroquine
3. Valve surgery

Prevention

• Vaccination
• Education to the public
• Quarantine of infected animals
• Pasteurized milk

Identification of those at high risk;

• Pregnant women
• Patients with cardiac valvular disease or vascular grafts