title: Sensitivity of PCR targeting the IS2404 insertion sequence of Mycobacterium ulcerans in an Assay using punch biopsy specimens for diagnosis of Buruli ulcer.
abstract: Punch biopsy specimens from Mycobacterium ulcerans disease lesions were used to compare the sensitivities and specificities of direct smear, culture, PCR, and histopathology in making a diagnosis of M. ulcerans disease in a field setting. PCR for the insertion element IS2404 was modified to include uracil-N-glycosylase and deoxyuridine triphosphate instead of deoxythymidine triphosphate to reduce the risk of cross contamination. The "gold standard" for confirmation of clinically diagnosed Buruli ulcer was a definite histological diagnosis, a positive culture for M. ulcerans, or a smear positive for acid-fast bacilli (AFB), together with a possible histological diagnosis. For 70 clinically diagnosed cases of M. ulcerans disease, the modified PCR was 98% sensitive and gave a rapid result. The sensitivities of microscopy, culture, and histology were 42%, 49%, and 82%, respectively. The use of a 4-mm punch biopsy specimen was preferred to a 6-mm punch biopsy specimen since the wound was less likely to bleed and to need stitching. Given adequate technical expertise and the use of controls, the PCR was viable in a teaching hospital setting in Ghana; and in routine practice, we would recommend the use of Ziehl-Neelsen staining of biopsy specimens to detect AFB, followed by PCR, in AFB-negative cases only, in order to minimize costs. Histology and culture remain important as quality control tests, particularly in studies of treatment efficacy.
authors.affiliation: Komfo Anokye Teaching Hospital, KNUST, Kumasi, Ghana. rphillip@sghms.ac.uk
authors.forename: R
authors.initials: R
authors.lastname: Phillips
authors.forename: C
authors.initials: C
authors.lastname: Horsfield
authors.forename: S
authors.initials: S
authors.lastname: Kuijper
authors.forename: A
authors.initials: A
authors.lastname: Lartey
authors.forename: I
authors.initials: I
authors.lastname: Tetteh
authors.forename: S
authors.initials: S
authors.lastname: Etuaful
authors.forename: B
authors.initials: B
authors.lastname: Nyamekye
authors.forename: P
authors.initials: P
authors.lastname: Awuah
authors.forename: K M
authors.initials: KM
authors.lastname: Nyarko
authors.forename: F
authors.initials: F
authors.lastname: Osei-Sarpong
authors.forename: S
authors.initials: S
authors.lastname: Lucas
authors.forename: A H J
authors.initials: AH
authors.lastname: Kolk
authors.forename: M
authors.initials: M
authors.lastname: Wansbrough-Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004251:DNA Transposable Elements; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis*; D019911:Mycobacterium ulcerans / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D017192:Skin Diseases, Bacterial / Q000175:diagnosis*; D012883:Skin Ulcer / Q000175:diagnosis*
chemical_list: D004251:DNA Transposable Elements