Skip directly to search Skip directly to A to Z list Skip directly to site content
CDC Home

Appendix A: Q Fever Key Point Summaries

Acute Clinical Features

  • Prolonged fever (>10 days) with a normal leukocyte count, thrombocytopenia, and increased liver enzymes is suggestive of acute Q fever infection.
  • Children with Q fever generally have a milder acute illness than adults.
  • Children are more likely to have a rash than adults. Rash has been reported in up to 50% of children with acute Q fever.
  • Women infected with Q fever during pregnancy are at increased risk for miscarriage and preterm delivery.
  • Women of child-bearing age who receive a diagnosis of Q fever can benefit from pregnancy screening and counseling to guide health-care management decisions.

Chronic Clinical Features

  • Persons who are at high risk for development of chronic Q fever include persons with preexisting valvular heart disease, vascular grafts, or arterial aneurysms.
  • Infection during pregnancy and immunosuppression (e.g., from chemotherapy) are both conditions that have been linked to chronic Q fever development.
  • Endocarditis and infections of aneurysms or vascular prostheses are the most common forms of chronic Q fever and generally are fatal if untreated.
  • Chronic Q fever is rarely reported in children.
  • In contrast with adults, osteomyelitis is one of the most common findings in children with chronic Q fever.

Diagnosis

  • Polymerase chain reaction (PCR) of whole blood or serum provides rapid results and can be used to diagnose acute Q fever in approximately the first 2 weeks after symptom onset but before antibiotic administration.
  • A fourfold increase in phase II immunoglobulin G (IgG) antibody titer by immunofluorescent assay (IFA) of paired acute and convalescent specimens is the diagnostic gold standard to confirm diagnosis of acute Q fever. A negative acute titer does not rule out Q fever because an IFA is negative during the first stages of acute illness. Most patients seroconvert by the third week of illness.
  • A single convalescent sample can be tested using IFA in patients past the acute stage of illness; however, a demonstrated fourfold rise between acute and convalescent samples has much higher sensitivity and specificity than a single elevated, convalescent titer.
  • Diagnosis of chronic Q fever requires demonstration of an increased phase I IgG antibody (≥1:1024) and an identifiable persistent infection (e.g., endocarditis)
  • PCR, immunohistochemistry, or culture of affected tissue can provide definitive confirmation of infection by Coxiella burnetii.
  • Test specimens can be referred to CDC through state public health laboratories.

Treatment and Management

  • Because of the delay in seroconversion often necessary to confirm diagnosis, antibiotic treatment should never be withheld pending laboratory tests or discontinued on the basis of a negative acute specimen. In contrast, treatment of chronic Q fever should be initiated only after diagnostic confirmation.
  • Treatment for acute or chronic Q fever should only be given in clinically compatible cases and not based on elevated serologic titers alone (see Pregnancy section for exception).
  • Doxycycline is the drug of choice, and 2 weeks of treatment is recommended for adults, children aged ≥8 years, and for severe infections in patients of any age.
  • Children aged <8 years with uncomplicated illness may be treated with trimethoprim/sulfamethoxazole or a shorter duration (5 days) of doxycycline.
  • Women who are pregnant when acute Q fever is diagnosed should be treated with trimethoprim/sulfamethoxazole throughout the duration of pregnancy.
  • Serologic monitoring is recommended following acute Q fever infection to assess possible progression to chronic infection. The recommended schedule for monitoring is based on the patient's risk for chronic infection.

Occupational Exposure

  • The majority of occupationally related Q fever outbreaks in the United States have occurred among biomedical research facility workers exposed to infected pregnant ewes
  • Workplaces with employees at high risk for C. burnetii exposure (e.g., laboratories that experiment with C. burnetii and animal research facilities) should institute a Q fever medical surveillance and health education monitoring program. Engineering controls, administrative controls, and use of personal protective equipment are recommended when appropriate.
  • Use of standard precautions by health-care providers is sufficient to prevent Q fever transmission during routine care. Additional precautions should be used during aerosol-generating procedures.
  • Use of postexposure prophylaxis is not recommended for workers after a known or potential exposure; any acute febrile illness that occurs within 6 weeks of exposure warrants immediate treatment and medical evaluation.

Surveillance and Reporting

  • Human Q fever infection is a notifiable disease in the United States.
  • Health-care providers who identify a potential case of Q fever should notify the local/state health department, which can assist with diagnostic testing.
  • Surveillance and reporting of Q fever are key components of public health education and disease prevention efforts.


Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites. URL addresses listed in MMWR were current as of the date of publication.


All MMWR HTML versions of articles are electronic conversions from typeset documents. This conversion might result in character translation or format errors in the HTML version. Users are referred to the electronic PDF version (http://www.cdc.gov/mmwr) and/or the original MMWR paper copy for printable versions of official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.

 
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO
A-Z Index
  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #