Markers of infection in inpatients and outpatients with acute Q-fever.
BACKGROUND
Query-fever (Q-fever) is a zoonotic infection caused by the intracellular Gram-negative coccobacillus Coxiella burnetii. A large ongoing outbreak of Q-fever has been reported in the Netherlands. We studied various markers of infection in inpatients (hospitalised) and outpatients (treated by a general physician) with acute Q-fever in relation to disease severity.


METHODS
Leukocyte counts, C-reactive protein (CRP) and procalcitonin (PCT) concentrations were measured in 25 inpatients and 40 outpatients upon presentation with acute Q-fever. Chest X-rays, if available, were analysed and confusion, urea, respiratory rate, blood pressure-age 65 (CURB-65) scores, indicating severity of pneumonia, were calculated.


RESULTS
CRP was the only marker that significantly differentiated between inpatients and outpatients. It was increased in all patients from both groups. Leukocyte counts and PCT concentrations did not differ between inpatients and outpatients. Overall, only 13/65 patients had an increased leukocyte count and only 11/65 patients presented with PCT concentrations indicative of possible bacterial respiratory tract infection. Infiltrative changes on the chest X-ray were observed in the majority of patients. CURB-65 score was 0+/-1 (mean+/-SD).


CONCLUSIONS
Acute Q-fever, a relatively mild pneumonia with low CURB-65 scores, specifically induces a response in CRP, while PCT concentrations and leukocytes are within the normal range or increased only marginally.
de Wit
Norbert C J
NC
Laboratory for Clinical Chemistry and Haematology, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. b.de.wit@jbz.nl
de Jager
Cornelis P C
CP
Meekelenkamp
Jamie C E
JC
Schoorl
Marianne
M
van Gageldonk-Lafeber
Arianne B
AB
Leenders
Alexander C A P
AC
Kusters
Ron
R
Wever
Peter C
PC
D000208:Acute Disease; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis* / Q000276:immunology; D002116:Calcitonin / Q000032:analysis / Q000276:immunology; D015740:Calcitonin Gene-Related Peptide; D006801:Humans; D007297:Inpatients; D007958:Leukocyte Count; D010045:Outpatients; D011014:Pneumonia / Q000175:diagnosis* / Q000276:immunology; D011498:Protein Precursors / Q000032:analysis / Q000276:immunology; D011778:Q Fever / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide