Table 1 Historical data and time lines of onchocerciasis control activities in Sierra Leone
Year | Event | Comments |
|---|---|---|
1926 | The endemicity of onchocerciasis was demonstrated in Sierra Leone when Blacklock first described its transmission through the black fly, S. damnosum in the Kono district | Â |
1957 | Start of onchocerciasis control efforts with insecticide treatment along the Tonkolili River that was found to be the most severely affected | Â |
1974 | Launch of the Onchocerciasis Control Programme in West Africa (OCP) in 7 countries (Benin, Burkina Faso, Cote d’Ivoire, Ghana, Mali, Niger and Togo) | Focus was on vector control but chemotherapy was added in the late 1980s and early 2000s |
1988/9 | OCP was extended to four other countries - Guinea, Guinea-Bissau, Senegal and Sierra Leone | Â |
1989 | The National Onchocerciasis Control Program (NOCP) was established in Sierra Leone under the OCP | Â |
1995 | Launch of the African Programme for Onchocerciasis Control (APOC) | Initiated the community-directed treatment with ivermectin (CDTI) strategy |
1991–2002 | Civil conflict in Sierra Leone resulted in limited onchocerciasis activities | Treatment coverage before 2002 are considered unreliable |
2003 | Onchocerciasis control activities was restarted as part of the Special Intervention Zones (SIZ) programme (2003–2007) that was managed by APOC | CDTI was implemented in meso- and hyper-endemic areas of the 12 endemic districts with very poor epidemiological and geographic coverage in 2003–2004 |
1998–2005 | Epidemiological mapping was conducted with support from APOC, showing high onchocerciasis prevalence along the main rivers and existence of black flies in the entire country except in areas around the capital Freetown and the southern coastal plain of the Bonthe district | A total of 177 sites were surveyed using skin snip method across 14 districts in the country. |
2005 | Management changes made within the NOCP by the Ministry of Health and Sanitation (MOHS) to improve onchocerciasis control efforts in the country | Better treatment coverage reported since then |
2007 | The NOCP expanded to become the national integrated Neglected Tropical Disease Programme (NTDP) to include onchocerciasis, lymphatic filariasis (LF), schistosomiasis and soil-transmitted helminths. Trachoma was demonstrated to be non-endemic in Sierra Leone. | Onchocerciasis and LF activities integrated since then in all 12 co-endemic districts by co-administering albendazole and ivermectin treating all hyper-, meso- and hypo-endemic villages for onchocerciasis. |
2009 | Paradigm shift from control of onchocerciasis as a public health problem (reduction of O. volvulus microfilaridermia prevalence to an acceptable low level although transmission will continue) to eliminating the disease by stopping local transmission | This was after studies in Senegal and Mali showed that through treatment with ivermectin it is possible to eliminate the disease |