"The ox tail is the toughest bit to chew," says Herodes Sacramento Rompao, director of the National Centre for Endemic Diseases in Sao Tome and Principe.

His conundrum is malaria. His tiny country on two islands off the coast of Gabon with a population of 180,000 has cut its malaria burden dramatically since 2004. From first cause of death malaria dropped to third. But last year saw a four-fold spike in deaths from cerebral malaria. Red lights are flashing.

Endemic malaria has ravaged the islands for centuries. In colonial times, it decimated the slave and indentured labour force in the sugarcane, cacao and coffee plantations of the Portuguese.

Malaria control improved after independence in 1975 but the disease remained endemic. In 2004, when the anti-malarial campaign started, there were 65,000 cases and 169 deaths. This plummeted to 2,700 cases and three deaths in 2007 - "a vertiginous drop", says Rompao.

The drop was impressive among children under 5 years of age: to just over 1,000 in 2007 from nearly 29,000 cases in 2003. The main hospital in the capital closed two paediatric wards for lack of patients.

The country was tantalizingly close to enter what the World Health Organisation (WHO) calls the pre-elimination phase*.

"That chance is gone," says Men-Fang Shaio, head of the malaria control project at the Taiwanese Medical Mission in Sao Tome.

Last year saw a surge of cerebral malaria with 12 deaths, half of them children.

Why? One reason is complacency. People think that malaria is history and roll up the nets. Mothers delay taking a feverish child to the health post. Some people also mistakenly believe that malaria blood tests detect HIV, which carries high stigma with it.

Another reason is increasing rejection of spraying homes with insecticide. This is a pillar of the anti-malaria strategy, along with giving out insecticide-treated bed nets at schools and health posts; preventive drugs for pregnant women; artemisinin-based therapy as the first-line drug for treatment, and awareness campaigns.

Only 66 percent of homes were sprayed as of July 2009 compared to 87 percent in 2005. To be effective, 80 percent of homes need to be sprayed. "Otherwise, it is a waste of money," explains Men-Fang.

Taiwan funded and organised the spraying until the end of 2007. The annual spraying is now contracted to the local NGO Zatona-Adil but kicked off only in July 2009 due to bureaucratic delays.

Frequently, the spraying teams find homes locked or homeowners refuse to let them in.

"People have strategies to avoid us," says Dionisio Amado, director of Zatona-Adil.

The reasons range from the reasonable to the whimsical and the urban legend:

- Allergies to the insecticide - Having to empty your home of furniture for two hours during the rainy season - Middle-class homeowners believe they don't need to spray their homes because they have air conditioning and mosquito nets - "Development aid syndrome": people expect to get something out of it, besides better public health - People mistakenly believe that spraying teams will tell authorities about illegal electrical connections or that the teams sell the insecticide and spray with water. What to do? A combination of carrot and stick.

The government is considering a fine of 10 million dobras (about $655) for those who refuse to spray their homes - although only the elite of this poor country could pay the fine.

Zatona-Adil says that more people will be willing the protect their homes if they were given something in return, for example free mosquito nets, and this technique worked when the NGO tried it out in one area. The organisation adds that this should be combined with door-to-door malaria awareness campaigns and preaching in churches.

Is the anti-malarial campaign failing so far? It depends on how you define success.

Sao Tome may have missed a few tricks but it should keep up the drive and talk to people in their homes, especially when a popular Brazilian soap opera is on.

"To eradicate malaria is not an easy job, even in a small country," says Men-Fang somewhat ruefully.

And the last push is the toughest.

NOTES

* WHO: A country moves from the control to the pre-elimination step when diagnostic tests show that less than 5 percent of suspected malaria cases are actually malaria.

WHO chart of malaria control stages

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