A press release yesterday announced that, “Research in Zanzibar, Tanzania has found a remarkable fall in the number of children dying from malaria. Within a three-year period (2002 to 2005), malaria deaths among the islandsâ€™ children dropped to a quarter of the previous level and overall child deaths to half.”
Zanzibar is an island, and that makes control of any disease special. Mabaso, Sharp and Lengeler conducted a historical review of malaria control in Africa and looked especially at IRS efforts between the 1940s and 1960s. They noted that, “IRS was not taken to scale in most endemic areas of the continent with the exception of southern Africa and some island countries such as Reunion, Mayotte, Zanzibar, Cape Verde and Sao Tome.” Malaria has returned to some of these islands, and the authors warn that IRS by itself is not a magic bullet.
A key feature of the effort in Zanzibar was the use of ACTs and LLINs together. These interventions have been supported by both the US President’s Malaria Initiative and the Global Fund to Fight AIDS, TB and Malaria, which has provided assistance for both treatment and LLINs specifically to Zanzibar in Rounds 1 and 4.
Progress on Bioku Island in Equatorial Guinea is happening, but not at the same rate as Zanzibar. Marathon Oil has helped with IRS and ExxonMobil with nets. Marathon reports that annual insecticide spraying campaigns started February 2004., and the program achieved “44% reduction of malaria parasites in children and 95% reduction in malaria transmitting mosquitoes.” Researchers have also documented “42% fewer infections occurring in 2006 compared with baseline (2004)” and reduction associated with recent house spraying or net use. They also stressed the need for comprehensive monitoring of coverage and correct use of IRS and ITNs, as there were variations in mosquito populations on the island.
Sao Tome also experienced a drop in malaria prevalence after a successful pilot ITN program. Currently Sao Tome is using GFATM money to implement a mixed method strategy and scale up free distribution of insecticide-bed nets, community-based management of malaria, provision of information, education and communication (IEC) about malaria, Intermittent Preventive Treatment (IPT), and artemisinin-based combination therapies (ACTs).
While disease control on an island may appear simple, the process is obviously a microcosm of the challenges faced on the mainland. Lessons from the eradication days show that one strategy alone may not yield long term results. Hopefully Zanzibar’s lessons of mixed approaches to malaria control will guide other national malaria control programs.