Table 6. Impact of local reference laboratory and external quality assurance measures on BUD control.
| Year of clinical presentation | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2007–2010 | 2011–2012 |
| No. of confirmed BUD patients a | 10 | 38 | 33 | 38 | 41 | 11 | 119 | 52 |
| No. of confirmed patients with non-ulcerative lesion | 3 | 6 | 12 | 23 | 21 | 5 | 44 | 26 |
| No. of confirmed patients with ulcerative lesions | 7 | 32 | 21 | 15 | 20 | 6 | 75 | 26 |
| Rate of confirmed BUD patients with non-ulcerative lesionsb | 30.0% (3/10) | 15.8% (6/38) | 36.4% (12/33) | 60.5% (23/38) | 51.2% (21/41) | 45.5% (5/11) | 37.0% (44/119) | 50.0% (26/52) |
| Rate of confirmed BUD patients – category I c | 20.0% (2/10) | 50.0% (19/38) | 24.2% (8/33) | 39.5% (15/38) | 46.3% (19/41) | 36.4% (4/11) | 36.9% (44/119) | 44.2% (23/52) |
| 95% confidence interval | 0–44.8 | 34.1–65.9 | 9.6–38.9 | 23.9–55.0 | 31.1–61.6 | 7.9–64.8 | 28.3–45.6 | 30.7–57.7 |
| Rate of confirmed BUD patients – category II d | 30.0% (3/10) | 36.8% (14/38) | 30.3% (10/33) | 31.6% (12/38) | 34.2% (14/41) | 45.5% (5/11) | 32.8% (39/119) | 36.6% (19/52) |
| 95% confidence interva | 1.6–58.4 | 21.5–52.2 | 14.6–46.0 | 16.8–46.4 | 19.6–48.7 | 16.0–74.9 | 24.3–41.2 | 23.5–49.6 |
| Rate of confirmed BUD patients – category III e | 50.0% (5/10) | 13.2% (5/38) | 45.5% (15/33) | 29.9% (11/38) | 19.5% (8/41) | 18.1% (2/11) | 30.3% (36/119) | 19.2% (10/52) |
| 95% confidence interval | 19.0–81.0 | 2.4–23.9 | 28.5–62.4 | 14.5–43.4 | 7.4–31.6 | 0–41.0 | 22.0–38.5 | 8.5–29.9 |
| Mean duration of disease before clinical diagnosis in days f | ||||||||
| Patients with non-ulcerative lesions | 318.7 | 74.0 | 25.8 | 24.8 | 30.3 | 54.6 | 51.8 | 35.0 |
| 95% confidence interval | 0–718.2 | 16.7–131.4 | 12.6–38.9 | 16.6–33.1 | 18.7–41.9 | 23.2–86.0 | 19.0–84.7 | 23.5–46.5 |
| Patients with ulcerative lesions | 386.0 | 239.2 | 107.6 | 71.8 | 87.5 | 64.0 | 182.6 | 82.1 |
| 95% confidence interval | 78.3–693.7 | 118.2–360.1 | 59.6–55.6 | 45.6–98.0 | 48.0–27.0 | 45.0–83.0 | 119.2–245.9 | 51.3–112.8 |
| All patients | 365.8 | 213.1 | 77.8 | 43.4 | 58.2 | 59.7 | 134.2 | 58.5 |
| 95% confidence interval | 130.8–600.8 | 109.3–316.9 | 44.3–111.3 | 29.9–56.8 | 36.4–80.0 | 42.8–76.6 | 91.1–177.4 | 41.1–76.0 |
Table 6 shows analyses of clinical parameters (i.e. “type of lesion” and “duration of disease before clinical diagnosis”) among PCR confirmed BUD new cases to assess impact of the local reference laboratory and external quality assurance measures on BUD control in Togo. Therefore, data from a previous study (September 2007 through December 2010) prior to implementation of the national reference laboratory at INH were analyzed and compared with data obtained in the present study (January 2011 through April 2012). Analysis for linear trends in proportions revealed a significant (p<0.01) increase of patients presenting with non-ulcerative lesions from 37.0% (2007–2010) to 50.0% (2011–2012). The mean duration of disease among patients with non-ulcerative lesions before presentation and establishment of clinical diagnosis decreased not significantly from 51.8 (95% CI: 19.0–84.7) to 35.0 (95% CI: 23.5–46.5) days during the two observation periods. However, the mean duration of disease among patients with ulcerative lesions before presentation of patients and establishment of clinical diagnosis decreased significantly from 182.6 (95% CI: 119.2–245.9) to 82.1 (95% CI: 51.3–112.8) days during the two observation periods. Furthermore, analysis of the development of categories of lesions showed a statistically non significant decrease from 30.3% (95% CI: 22.0–38.5) to 19.2% (95% CI: 8.5–29.9) of category III lesions. BUD, Buruli ulcer disease; CI, confidence interval.
Number of confirmed BUD patients, laboratory confirmation was conducted by standard IS2404 PCR, IS2404 DRB-PCR and/or IS2404 qPCR.
Rate of confirmed BUD patients with non-ulcerative lesions among all confirmed BUD patients per observation period.
Category I, single lesion <50 mm in diameter.
Category II, single lesion between 50 and 150 mm in diameter.
Category III, single lesion >150 mm in diameter or multiple lesions, osteomyelitis or lesions at critical sites.
Mean duration of disease in days based on the time from first recognition of clinical symptoms by patients and availability of the clinical diagnosis “BUD”. Only data from PCR confirmed BUD patients were analyzed.