Details of duration of chemoprophylaxis
| Years of study | Duration of treatment regimen (months) | No of patients |
|---|---|---|
| Nov 1981–Dec 1983 | 9 | 2201-150 |
| 1984–6 | 6 | 119 (431-150) |
| 1987–8 | 4 | 53 |
| 1989–92 | 3 | 134 |
| 1993–6 | 3 | 79 |
↵1-150 Followed up for 15 months after cessation of chemoprophylaxis.