[3rd update, 23 June 2010]
Can we or can we not?: A Feasibility Assessment for the elimination of malaria on Zanzibar
And so the story continues. Chris Cotter from the Malaria Elimination Group alerted me to the following:
The recent success that Zanzibar has achieved in reducing its malaria burden has led the Zanzibar Malaria Control Program (ZMCP) to a point where it faces an important decision of whether to continue sustaining malaria control or to seek malaria elimination. To reach their decision, the ZMCP conducted an assessment to gauge the feasibility of reaching and sustaining malaria elimination from the operational, technical and financial perspectives. This feasibility assessment resulted in a series of evidence-based recommendations, and is the first robust analysis on the feasibility of elimination, therefore forming a strong foundation from which strategic decisions and programmatic shifts in Zanzibar can be made.
Many local and international experts provided technical advice to the feasibility assessment. This work benefited from the intellectual leadership of the Clinton Health Access Initiative and many members of the Malaria Elimination Group, with financial support provided by the UCSF Global Health Group through a grant from ExxonMobil.
The final report and recommendations on a way forward were recently presented to the senior leadership of the Zanzibar Ministry of Health and Social Welfare. Conclusions on the short- and long-term challenges of achieving and sustaining elimination are outlined as well as strategies that will be critical for elimination to succeed. The ZMCP has already begun implementing several of the recommended strategies, most notably strategies to enhance surveillance capacity, which are paramount for any elimination effort.
[end 3rd update]
On 6 May 2010, whilst on duty travel in Tanzania, I visited the island of Zanzibar where I had the pleasure to meet with the Permanent Secretary of Health, Dr. Mohamed Jiddawi. He features in the video below.
Dr. Jiddawi is a well-known and respected urologist, and admitted honestly and frankly when we sat down to discuss the malaria situation on Zanzibar that he is not a malariologist. I only had one question for him: Now that malaria is at its lowest level recorded in history, and almost gone, what will be done next?
First, he mentioned that the man at the helm of the US President’s malaria initiative (PMI), Admiral Timothy Ziemer, had visited the island last week. They had been discussing this very issue. Sustaining current control levels seems to be the priority, but vector elimination as such was not mentioned to me.
Also, estimates are now available regarding the number of people visiting the island from mainland Africa on a daily basis. Six thousand I was told. Six thousand potential parasite carriers that can infect the mosquito population on the island and sustain transmission. When Dr. Jiddawi mentioned the option of screening these visitors for parasites I could pick up a grain of uncertainty in his voice. Clearly, this will be very hard, if not impossible.
Next, he stressed the point of bednet use. People should know that they have to use their nets. ‘Nets, nets, nets’ he said. Only in that manner could the current success be maintained.
But will this lead to elimination of malaria from Zanzibar? Not likely. It was obvious that Dr. Jiddawi was well aware of the critical stage that the island has reached in combatting malaria. That they are nearly there. But also that the hard work is only still to start. Bringing malaria down to very low levels was relatively ‘easy’. Bringing it down to zero remains a massive challenge.
It is hoped that Dr. Jiddawi and all involved in the fight against malaria on Zanzibar will be given the time and resources to win the end battle and reach glorious success.
The world is watching, anxiously waiting to see the first chunk of Africa won back from the parasite’s deadly grip. Success on Zanzibar, after all, will boost the morale and confidence of all involved in the second malaria eradication era.
‘Yes we can’ beat malaria
‘It’s a dream come true’, says Zanzibar’s Ministry of Health official Dr. Mohamed Jiddawi in the following video. ‘The beds are empty, it’s good news’, adds Mark Green of MalariaNoMore. And indeed, an all-out integrated attack on malaria in Zanzibar, the idyllic island off the coast of Tanzania, has brought malaria prevalence down to below 0.7%. Down from the 30-40% where it was a mere five years ago. See for yourself…
What happened in Zanzibar? First, in 2003, the Ministry adopted artemisinin-based combination therapy (ACT), which halved parasite prevalence in the two years that followed. Second, in 2006, long-lasting insecticide treated bednets were introduced on a massive scale. It resulted in a further 10-fold reduction in children carrying the disease. Then came four rounds of indoor residual house spraying, and for the extra vulnerable (infants and pregnant women) intermittent preventive treatment (IPT) was added to the package. Good drugs to cure and prevent malaria. Insecticides to kill the mosquito population. Backed by large sums of funding the world witnessed Obama truism when it gets to beating malaria. Today the island enjoys the tranquillity of a tropical paradise no longer plagued by this ancient scourge.
But in spite of these encouraging results, there is reason for concern. Apparently, the recent victory on Zanzibar was history repeating itself. I looked up the data from past attempts to eradicate malaria on the island. Back in 1961, the World Health Organization embarked on a house-spraying programme that continued until 1968. With the same DDT that was used in recent years. By that time, prevalence dropped from >50 to 7.8% and malaria was no longer considered a problem. Spraying was abandoned. By 1973, just five years later, it was back. At a level higher than before the WHO campaign had started:
When Dr. Tachi Yamada, President of the Global Health Program at the Bill & Melinda Gates Foundation, wrote a commentary for CNN last fall following his visit to empty wards in Zanzibar, he wrote one striking sentence: ‘Zanzibar -- a relatively small but striking example -- has virtually eliminated the disease over the past five years.’
It is the word virtually that is key here. ‘Virtually’ is all the difference between elimination, the complete and sustainable disappearance of the disease, and temporary success. Like that witnessed in the 1960s. Einstein’s words ‘If you do what you did, you get what you got’ apply to Zanzibar’s malaria. Pour large sums of money in the battle against parasites and mosquitoes and you’ll knock it over the head. But you won’t eliminate it.
Zanzibar’s malaria situation in 2010 resembles that of 1968.
If Zanzibar succeeds in eliminating malaria it will boost global morale and probably raise unprecedented levels of funding to embark on mainland Africa. There’s a good example: Tsetse flies, that transmit sleeping sickness, were eliminated from Zanzibar a decade ago. Using the environmentally-friendly Sterile Insect Technique (SIT), in which large numbers of sterile male flies are released to mate with wild females that will not produce viable offspring. Call it birth control for insects. Flies were eliminated in Zanzibar. This success fuelled enthusiasm and a large SIT programme is currently underway in Ethiopia, backed by the UN’s International Atomic Energy Agency (IAEA). Small successes breed larger successes.
But for Zanzibar’s malaria the situation is more complicated. Every day, hundreds of people ferry across from Tanzania’s capital Dar es Salaam, many of these carrying the deadly parasite in their bloodstream. Ready to infect the small mosquito population that’s left on the island but enough to sustain transmission at low levels. This necessitates continuous efforts to curb the disease that, sadly, will bring two further problems: History shows that funding levels will not remain at the current level and donor fatigue will kick in. Sooner or later. Moreover, evolutionary forces will catch up with our efforts: parasites will become resistant to drugs, mosquitoes will laugh at our chemicals…
For now, Zanzibar remains vigilant. Clinics use mobile telephones to swiftly communicate local outbreaks of the disease and rapid response teams aim to control these and curtail further spread. But this will be finite...
The only way in which Zanzibar can free itself permanently from malaria is the total removal of the mosquito population responsible for transmitting it. Preferably with a mosquito-free zone in and around mainland Dar es Salaam to prevent mosquitoes from hitchhiking back to the island with the ferries.
The difference between 1968 and today is the fact that science has delivered the tools and strategies to eliminate mosquito populations within the framework of area-wide integrated pest management (AW-IPM). It can be done.
Zanzibar is nearly there, and now is the time to move beyond past successes. Freeing more than one million Zanzibaris from malaria forever or never is at stake. Zanzibar can be proud of its achievements, and its attainment of the MDG6 goal in terms of malaria is to be applauded. But now it has to go the extra mile.
Bhattarai, A. et al. (2007) Impact of Artemisinin-Based Combination Therapy and Insecticide-Treated Nets on Malaria Burden in Zanzibar. PLoS Medicine, 4(11): e309. Read it here.