Malaria control on Zanzibar Island

Jasson Urbach | 27 Nov 2007
Health Policy Unit

Earlier this month, the Southern African Development Community (SADC) commemorated the annual SADC malaria day, which occurs on the second Friday of November. The day that was chosen because it precedes the start of the peak malaria transmission period of January to April in most Southern African countries. Around this time, most countries prepare themselves for the coming malaria season and the purpose of the commemorations is to bring malaria control managers together to share ideas about what policies work in malaria control.

In the SADC region alone there are between 19 and 21 million cases of malaria each year and over 300,000 deaths. For malaria control programme managers currently struggling to control a disease that has ravaged the world and caused incalculable human suffering and misery for as long as man can remember, the small island of Zanzibar can offer some insights into reducing the burden of disease.

The intensive effort to control malaria on Zanzibar Island started about five years ago. In September 2003 the island introduced artemisinin based combination therapies (ACTs). At the time they were experiencing widespread failure, in the order of 60 per cent, to the existing first line treatment, namely, chloroquine. In 2005, nets were introduced, provided free of charge. Shortly after this the Zanzibar Malaria Control Programme (ZMCP) embarked on a comprehensive indoor residual spraying (IRS) campaign. To confirm the number of cases, clinics and health facilities use microscopy wherever possible. If this is not available they use highly effective rapid diagnostic tests (RDT), so treatment given to patients is virtually always based upon confirmed results. If patients are given treatments based on confirmed cases, it reduces the probability of the malaria parasite building up a resistance to existing treatments.

As a result of this integrated malaria control strategy, the number of cases in Zanzibar has fallen significantly. According to the ZMCP, malaria prevalence on the island fell from 48 per cent in 2002 to 31 per cent in May 2006. During our visit Dr. Abdullah Ali at the ZMCP informed us that malaria has now plummeted to less than one per cent. Effective malaria control saves lives, prevents the trauma of unnecessary deaths in families, and has beneficial economic consequences for those who are spared this debilitating disease. Malaria sufferers have great difficulty in carrying out sustained work, which exacerbates human misery and poverty in areas where the disease is prevalent.

Multiple interventions are important and the reduction in cases cannot be attributed to any one particular intervention. Malaria has no reservoir in the wild - the parasite exists only in mosquito and man. If the transmission is blocked for long enough the parasite population collapses and the disease disappears. Combining drug therapy for humans with integrated vector control strategies such as spraying small amounts of insecticide on the inside walls of houses, and sleeping under a net at night, provides the ammunition necessary to break the transmission and knock out the disease.

However, the ZMCP needs to institute a strict monitoring and evaluation regimen if it wishes to keep the deadly parasite at bay. The result of the effective malaria control programme is that the majority of people on Zanzibar have not had malaria for several years and have lost any natural immunity previously acquired. If there were to be a break-out of malaria the potential for an epidemic is high. The ZMCP therefore needs to constantly monitor the situation and be prepared for such an event. If politicians do not understand the intricacies of the parasite, it will be difficult to justify continued spending on control when it appears that the parasite is no longer prevalent.

The government currently funds only the salaries of individuals in the control programme whilst funding for commodities comes from external sources. Funding by external donors may be necessary to drive a comprehensive malaria control programme in the short run but if it were to be retracted, without a domestic commitment to fund priorities, an epidemic could strike with disastrous consequences.

Author: Jasson Urbach is an economist with the Free Market Foundation and a director of Africa Fighting Malaria. This article may be republished without prior consent but with acknowledgement to the author. The views expressed in the article are the author's and are not necessarily shared by the Health Policy Unit.