Eradication – lessons from the Nigerian guinea worm program

Guinea worm is an ancient disease technically known as Dracunculiasis medinensis – or medina dragon.  While some assume that the ‘M’ in medina should be capitalized as in the Saudi Arabian city, the name also comes from the smaller case medina that means town or city, for it was in such urban populations where the worm could best spread.

guinea-worm-nigeria-1988-2008.jpgA 1986 World Health Assembly resolution marked the start of eradication for this thread-like subcutaneous parasite that is well known for disabling productive populations and causing great economic hardship. In Nigeria the first national conference on the disease in 1987 presented the first systematically collected data that showed the extent of the worm in almost every state.  This led to the first national case search that documented over 600,000 cases nationwide.  The race began to eliminate the disease by 1995 in line with overall global eradication targets.

The Nigeria Guinea Worm Eradication Program (NIGEP) was launched in 1988 and used multiple strategies to contain the disease.  Strong efforts were made to get all government and donor water supply programs to site wells in guinea worm endemic villages. Filter cloths were produced to remove the ‘vector’, a species of water flea/crustacean known as cyclops, from local pond water. The chemical abate was applied in some cases to ponds.  Villagers were taught not to enter water sources if they had an open ulcer where the guinea worm was protruding to lay its larvae in the ponds.

As we can see from the attached chart, the number of guinea worm cases in 1995, the target date for elimination, was only 2.5% of the 1988 baseline, but the disease was still resistant to human control.  Improved water supply interventions were harder to organize than previously thought, and use of filters was not an easy behavior to adopt in all communities. A case containment strategy was then adopted that required prompt reporting of emergent worms by volunteer village guinea worm scouts and hopefully a quick response by the local health department to ensure everyone had a filter and that the affected person did not enter the water source/pond.

NIGEP reports no new guinea worm cases so far in 2009, and hope this spells the end of the disease in Nigeria. The chart shows slow but steady progress, with a few blips, but clearly, elimination was not easy even though people were prone to say it was an easy disease to eliminate since the cyclops could not move from their ponds and people could be taught to avoid or treat the pond water.  In real life nothing is simple, and now, nearly twenty years after efforts began in Nigeria, elimination might be possible.

With malaria, like guinea worm, any case is a cause for concern and a potential for further transmission.  If a ‘simple’ disease like guinea worm has taken 20 years to conquer in Nigeria, how much longer for malaria?  Mosquitoes don’t stay put. People have medicine but not always access or proper adherence attitudes.  Commodities like nets are eventually delivered in countries, but how long does it take to distribute them to the people in need?  Even then, like the guinea worm filters, will the nets be used properly.

Malaria is a complicated disease – eradication, let along elimination from any particular endemic country – is a looooong term goal.  With guinea worm, the first step was made with a commitment by the countries of the world in 1986. That commitment is eventually bearing fruit – commitment, patience and persistence are needed for malaria eradication to succed, too.

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