Diagnostic accuracy of the Leishmania OligoC-TesT and NASBA-Oligochromatography for diagnosis of leishmaniasis in Sudan.
BACKGROUND
The Leishmania OligoC-TesT and NASBA-Oligochromatography (OC) were recently developed for simplified and standardised molecular detection of Leishmania parasites in clinical specimens. We here present the phase II evaluation of both tests for diagnosis of visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and post kala-azar dermal leishmaniasis (PKDL) in Sudan.


METHODS
The diagnostic accuracy of the tests was evaluated on 90 confirmed and 90 suspected VL cases, 7 confirmed and 8 suspected CL cases, 2 confirmed PKDL cases and 50 healthy endemic controls from Gedarif state and Khartoum state in Sudan.


RESULTS
The OligoC-TesT as well as the NASBA-OC showed a sensitivity of 96.8% (95% CI: 83.8%-99.4%) on lymph node aspirates and of 96.2% (95% CI: 89.4%-98.7%) on blood from the confirmed VL cases. The sensitivity on bone marrow was 96.9% (95% CI: 89.3%-99.1%) and 95.3% (95% CI: 87.1%-98.4%) for the OligoC-TesT and NASBA-OC, respectively. All confirmed CL and PKDL cases were positive with both tests. On the suspected VL cases, we observed a positive OligoC-TesT and NASBA-OC result in 37.1% (95% CI: 23.2%-53.7%) and 34.3% (95% CI: 20.8%-50.9%) on lymph, in 72.7% (95% CI: 55.8%-84.9%) and 63.6% (95% CI: 46.6%-77.8%) on bone marrow and in 76.9% (95% CI: 49.7%-91.8%) and 69.2% (95% CI: 42.4%-87.3%) on blood. Seven out of 8 CL suspected cases were positive with both tests. The specificity on the healthy endemic controls was 90% (95% CI: 78.6%-95.7%) for the OligoC-TesT and 100% (95% CI: 92.9%-100.0%) for the NASBA-OC test.


CONCLUSIONS
Both tests showed high sensitivity on lymph, blood and tissue scrapings for diagnosis of VL, CL and PKDL in Sudan, but the specificity for clinical VL was significantly higher with NASBA-OC.
Saad
Alfarazdeg A
AA
Department of Biochemistry, Khartoum University, Sudan.
Ahmed
Nuha G
NG
Osman
Osman S
OS
Al-Basheer
Ahmed Almustafa
AA
Hamad
Awad
A
Deborggraeve
Stijn
S
Büscher
Philippe
P
Schoone
Gerard J
GJ
Schallig
Henk D
HD
Laurent
Thierry
T
Haleem
Ahmed
A
Osman
Omran F
OF
Eltom
Ahmed Mohamedain
AM
Elbashir
Mustafa I
MI
El-Safi
Sayda
S
D000818:Animals; D001769:Blood / Q000469:parasitology; D001853:Bone Marrow / Q000469:parasitology; D006801:Humans; D007891:Leishmania / Q000302:isolation & purification*; D007896:Leishmaniasis / Q000175:diagnosis*; D008198:Lymph Nodes / Q000469:parasitology; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010274:Parasitology / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013397:Sudan
D011933:Reagent Kits, Diagnostic