Improving the accuracy of syndromic diagnosis of genital ulcer disease in Malawi.
OBJECTIVE
Most resource-poor settings rely on syndromic criteria to diagnose genital ulcer disease (GUD). However, the etiologic pathogens of GUD vary temporally and geographically, and current criteria may not reflect changes in the prevalence of specific pathogens.


METHODS
In 1999, we estimated the prevalence of Treponema pallidum (Tp), herpes simplex virus (HSV), and Haemophilus ducreyi (Hd) in Malawi. We then used regression coefficients of independent correlates of HSV and Hd to develop weighted diagnostic algorithms, in which weights were beta-coefficients corresponding to each factor.


RESULTS
Overall, a decrease in the proportion of sexually transmitted disease attributable to GUD was noted in 7 years. Thirty-five percent were attributable to HSV, 30% to H. ducreyi, and 4% to T. pallidum. Areas under the receiver operating characteristic curves for weighted and unweighted HSV diagnostic algorithms were 67.6% and 66.5%, respectively. There was no significant difference in the explanatory performance of the weighted and unweighted algorithms.


CONCLUSIONS
Unweighted algorithms can therefore be used to improve diagnostic accuracy of GUD.
Hoyo
Cathrine
C
Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. hoyo0001@mc.duke.edu
Hoffman
Irving
I
Moser
Barry K
BK
Hobbs
Marcia M
MM
Kazembe
Peter
P
Krysiak
Robert G
RG
Cohen
Myron S
MS
D000328:Adult; D000465:Algorithms; D002602:Chancroid / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006191:Haemophilus ducreyi / Q000302:isolation & purification; D006561:Herpes Simplex / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D006801:Humans; D008295:Malawi / Q000453:epidemiology; D008297:Male; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015995:Prevalence; D012372:ROC Curve; D012749:Sexually Transmitted Diseases / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D018139:Simplexvirus / Q000302:isolation & purification; D013587:Syphilis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D014210:Treponema pallidum / Q000302:isolation & purification