Hookworm, a one-centimeter-long parasite named after the tooth it uses to latch onto the small intestine of its victims, is considered one of the great forgotten plagues of the early 21st century.

``It's very widespread in rural areas around here,'' said a doctor surnamed Li at the Wanning City People's Hospital. ``Many of the patients are children.''

As most farmers do not have enough money to see a doctor, Li and his colleagues have little idea how many people in the area have the disease, but a rough estimate is about 90 percent.

People just learn to live with it, and as a result, an estimated 78 million rural dwellers in China still suffer from the disease, according to the most recent survey conducted with World Health Organization backing last year.

The consequences are devastating and irreversible if no treatment is given, according to Peter Hotez, a researcher at George Washington University who has devoted years of his career to study the parasite and find possible remedies.

``It literally sucks the blood out of the poor peasants in China,'' he said. ``It stunts physical development and affects cognitive and intellectual development.''

The blood lost to hookworms in China is staggering, corresponding to the amount donated by 80 million individuals every single year, according to calculations by Hotez.

Victims suffer from iron and protein deficiency and on average end up seeing their wage earning potential reduced by 40 percent.

That creates a vicious cycle which has kept large parts of the country in the grasp of poverty for decades.

``It mostly occurs in poor areas. And it produces poverty itself,'' said Hotez.

Unlike the case with other major diseases, authorities have never had major success in wiping this one out. Mostly, experts say, because they have not tried hard enough.

The vast majority of health officials live in the cities, which means they often ignore rural problems.

``I've had a health official tell me hookworm is no problem in China,'' said Hotez. ``There's this urban-rural schizophrenia in China.''

Hookworm is usually transmitted via the skin, typically when farmers walk barefoot through fields fertilized with human feces.

That means it is especially likely to occur in areas with too little money to organize good sanitation. ``It's so intimately linked with poverty. It's almost a marker of poverty,'' Hotez said.

Two drugs known as mebendazole and albendazole are used to counter the parasite.

The cost is negligible, and 100 children can be treated for about US$2 (HK$15.60). ``It's so cheap to treat them,'' said Antonio Montresor, a Hanoi-based expert on parasitic diseases with the WHO.

``I see no reason why a country like China shouldn't organize something for this.''

While the disease has had a low priority on the central government agenda so far, the WHO hopes last year's survey will push it up the official agenda in Beijing.

The survey, conducted by a Shanghai research center, for the first time revealed the real extent of the problem, which could help the policy process get started.

``The whole idea is to hand the survey over to the Ministry of Health and the State Council,'' said Jeff Gilbert, a WHO researcher. ``They will review the document and then probably make policy on that.''

Cambodia has shown the way for other nations in the region, treating three million children with the drugs last year, the WHO said.

``The fact that a poor country like Cambodia was able to implement this, I think, demonstrates that all countries with this disease could do the same,'' Montresor said.

The disadvantage of the drug is that it must be taken regularly, once or twice a year, which is not always feasible in remote rural areas with poor infrastructure and little interaction between officials and citizens.

But a glimmer of hope has now appeared.

Hotez and his colleagues have developed a vaccine in the form of a genetically modified protein, which will soon enter into clinical testing in Brazil.

The big pharmaceutical companies would never have been able to come up with a similar solution, according to Hotez.

``For-profit organizations, especially public companies, need to be responsible to their shareholders and deliver a profit,'' he said.

``And there's no way of making a hookworm vaccine profitable.'' AGENCE FRANCE-PRESSE