Discriminating malaria from dengue fever in endemic areas: clinical and biological criteria, prognostic score and utility of the C-reactive protein: a retrospective matched-pair study in French Guiana.
BACKGROUND
Dengue and malaria are two major public health concerns in tropical settings. Although the pathogeneses of these two arthropod-borne diseases differ, their clinical and biological presentations are unspecific. During dengue epidemics, several hundred patients with fever and diffuse pain are weekly admitted at the emergency room. It is difficult to discriminate them from patients presenting malaria attacks. Furthermore, it may be impossible to provide a parasitological microscopic examination for all patients. This study aimed to establish a diagnostic algorithm for communities where dengue fever and malaria occur at some frequency in adults.


RESULTS
A sub-study using the control groups of a case-control study in French Guiana--originally designed to compare dengue and malaria co-infected cases to single infected cases--was performed between 2004 and 2010. In brief, 208 patients with malaria matched to 208 patients with dengue fever were compared in the present study. A predictive score of malaria versus dengue was established using .632 bootstrap procedures. Multivariate analysis showed that male gender, age, tachycardia, anemia, thrombocytopenia, and CRP>5 mg/l were independently associated with malaria. The predictive score using those variables had an AUC of 0.86 (95%CI: 0.82-0.89), and the CRP was the preponderant predictive factor. The sensitivity and specificity of CRP>5 mg/L to discriminate malaria from dengue were of 0.995 (95%CI: 0.991-1) and 0.35 (95%CI 0.32-0.39), respectively.


CONCLUSIONS
The clinical and biological score performed relatively well for discriminating cases of dengue versus malaria. Moreover, using only the CRP level turned to be a useful biomarker to discriminate feverish patients at low risk of malaria in an area where both infections exist. It would avoid more than 33% of unnecessary parasitological examinations with a very low risk of missing a malaria attack.
CIC-EC Antilles Guyane CIE 802 Inserm, Centre Hospitalier Andrée Rosemon, Cayenne, French Guiana ; Research team EPaT EA 3593, University of French West Indies and French Guiana, Cayenne, French Guiana ; AP-HP, Hôpital Pitié-Salpêtrière, Service de maladies Infectieuses et Tropicales, Paris, France.
Loïc
L
Epelboin
Charlotte
C
Boullé
Sihem
S
Ouar-Epelboin
Matthieu
M
Hanf
Philippe
P
Dussart
Félix
F
Djossou
Mathieu
M
Nacher
Bernard
B
Carme
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015510:Clinical Medicine / Q000379:methods*; D003715:Dengue / Q000175:diagnosis* / Q000473:pathology*; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D005616:French Guiana; D006801:Humans; D007223:Infant; D008288:Malaria / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
D002097:C-Reactive Protein