ﺑﺎﺯﮔﺸﺖ ﺑﻪ ﺻﻔﺤﻪ ﻗﺒﻠﯽ
خرید پکیج
تعداد آیتم قابل مشاهده باقیمانده : -35 مورد

United States Centers for Disease Control and Prevention surveillance case definition for chronic Q fever

United States Centers for Disease Control and Prevention surveillance case definition for chronic Q fever
  Acute Q fever Chronic Q fever
Clinical evidence of infection Fever and 1 or more of the following: rigors, severe retrobulbar headache, acute hepatitis, pneumonia, or elevated liver enzymes Newly recognized culture-negative endocarditis (particularly in a patient with previous valvulopathy or compromised immune system); suspected infection of a vascular aneurysm or vascular prosthesis; or chronic hepatitis, osteomyelitis, osteoarthritis, or pneumonitis in the absence of other known etiology
Laboratory criteria*¶ Laboratory confirmed (1 or more of the following): Laboratory confirmed (1 or more of the following):
  • Fourfold change in IgG antibody titer to Coxiella burnetii phase II antigen by IFA between paired sera
  • IgG titer ≥1:800Δ to C. burnetii phase I antigen by IFA
  • Detection of C. burnetii DNA in a clinical specimen by PCR
  • Detection of C. burnetii DNA in a clinical specimen by PCR
  • Demonstration of C. burnetii in a clinical specimen by IHC
  • Demonstration of C. burnetii in a clinical specimen by IHC
  • Isolation of C. burnetii from a clinical specimen by culture
  • Isolation of C. burnetii from a clinical specimen by culture
  
Laboratory supportive (1 or more of the following): Laboratory supportive:
  • Single IgG titer ≥1:128 to C. burnetii phase II antigen by IFA (phase I titers may be elevated as well) or
  • IFA IgG titer ≥1:128 and <1:800Δ to C. burnetii phase I antigen
  • Elevated phase II IgG or IgM antibody reactive with C. burnetii antigen by ELISA, dot-ELISA, or latex agglutination
  
Case classification Confirmed acute Q fever: Confirmed chronic Q fever:
  • Laboratory confirmation with clinical evidence of infection or an epidemiologic link to a laboratory-confirmed case
  • Clinical evidence of infection with laboratory confirmation
Probable acute Q fever: Probable chronic Q fever:
  • Clinical evidence of infection with laboratory-supportive results
  • Clinical evidence of infection with laboratory-supportive results

DNA: deoxyribonucleic acid; ELISA: enzyme-linked immunosorbent assay; IFA: indirect immunofluorescence antibody assay; IgG: immunoglobulin G; IgM: immunoglobulin M; IHC: immunohistochemistry; PCR: polymerase chain reaction.

* CDC prefers simultaneous testing of paired samples. IgM tests are not strongly supportive of serodiagnosis because the response might be persistent (making it unreliable as an indicator of recent infection) or nonspecific (resulting in false positives). ELISA tests are not quantitative and cannot be used to measure changes in antibody titer; thus, they can only be used for classification of probable cases. Performing laboratories determine the appropriate cutoff titers for ELISA. Serologic test results should be interpreted with caution because baseline antibodies acquired as a result of previous exposure to Q fever might exist, especially in patients with rural or farming backgrounds.

¶ Patients with suspected chronic Q fever should be evaluated for titers both to phase I and phase II antigens. Serologic test results should be interpreted with caution because baseline antibodies acquired as a result of previous exposure to Q fever might exist, especially in patients with rural or farming backgrounds.

Δ United States laboratories use a twofold dilution scheme that does not result in a titer equaling 800; in the United States, a titer of 1024 is equivalent to a titer of 800.

Reproduced from: Anderson A, Bijlmer H, Fournier PE, et al. Diagnosis and management of Q fever--United States, 2013: Recommendations from CDC and the Q Fever Working Group. MMWR Recomm Rep 2013; 62:1. https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6203a1.htm (Accessed on November 13, 2024).
Graphic 146976 Version 1.0