Table 3. Relapse following VL and PKDL in the Indian subcontinent.
| Reference | Bangladesh | India | Nepal | |
|---|---|---|---|---|
| VL relapse | ||||
| Incidence of VL relapse | ||||
| - post-antimonial VL treatment | [103–106] | 0.6% (1y) | 0.14–1.67% (1y); 67% (HIV co-infected– 1y); | |
| - post-miltefosine VL treatment | [29,31,109,112–118] | 1.6–11.1% (6mo); 7.6–12.8% (1y); | 6–10.8% (6mo); 12.8–20.0% (1y); | |
| - post liposomal amphotericin treatment | [9,32,33,107,108,110,116] | 3.6% | 0–0.26% (6mo); 1.39–3.7% (1y); 8.1% (HIV co-infected - 1y); 26.5% (HIV co-infected - 2y); 17–49.1% (HIV co-infected); | |
| Duration to relapse distribution (post-liposomal amphotericin treatment) | [108] | 15.1% (<6mo); 52.9% (6 – 12mo); 31.9% (>12mo); | ||
| Duration to relapse | [29,32,108,110] | 3.75–10.1mo; 10mo (HIV co-infected) | ||
| Risk factors for VL relapse following treatment with miltefosine or liposomal amphotericin | ||||
| - children (cf adults) OR | [31,108,109,113] | 1.94–3.54 | 3.19 | |
| - male (cf female) OR | [108,109] | 1.74–2.14 | 2.14 | |
| - decrease in spleen size < 0.5cm/day at discharge OR | [108,109] | 1.0–1.55 | 1.0 | |
| - longer duration of symptoms prior to treatment OR | [108,109] | 0.62–1.0 | 1.0 | |
| - Risk of relapse with HIV co-infection | [9,21,110] | 16% (1y); 20% (2y); 26% (4y); 6.4% (1y) (combination therapy) | ||
| - Anti-retroviral therapy for HIV co-infection after admission RR | [110] | 0.25 | ||
| Markers for VL relapse | ||||
| - rk39 ELISA titres | [64] | No correlation | ||
| - parasite genotype | [31] | No difference between cured VL and relapse; | ||
| - CD+4 count (in HIV-co-infected) | [103,107] | <200 /cmm | ||
| - promastigote morphology | [30] | Procyclic: Longer slender body; Metacyclic: shorter body; Increased metacyclogenesis; | ||
| - macrophages | [30] | Higher percentage of macrophages infected with parasite; | ||
| PKDL relapse | ||||
| Incidence of PKDL relapse following PKDL | [9,88,92,119,120] | 13% | 0–12.5% (post-miltefosine); 22%; | |
| Risk factors for PKDL relapse | ||||
| - drug dosage | [92] | No correlation; | ||
| - treatment duration | [121] | 43% (post-miltefosine for 3mo); 0% (post-miltefosine for 4mo); | ||
| Parasite resistance (drug susceptibility) | ||||
| - promastigote survival (IC50) | [122] | PKDL: 11.45 (SD: 4.19); VL: 2.58 (SD: 1.58) | ||
| - promastigote survival (IC50) (VL relapse following VL) | [31,122] | Pre-miltefosine: 1.86; Post-miltefosine cured: 2.43; Post-miltefosine relapse: 4.72; | No difference between cured VL and relapse; | |
| - promastigote survival (IC50) (PKDL relapse) | [122] | Pre-miltefosine: 8.63; Post-miltefosine relapse: 16.13; | ||
Note: IC50 (Inhibitory concentration 50%); SD (Standard deviation); cf (compared from); OR (Odds ratio); rk39 (recombinant kinetoplast 39); ELISA (Enzyme linked immunosorbent assay)