Experts say governments treat 'big name' ailments like Aids and malaria when many which kill far more people in the developing world could be eradicated cheaply

More than a billion victims of some of the world's most pernicious ailments could be treated with drugs that have annual costs of less than 30p a person.

However, the plight of these people is being neglected because resources are being monopolised in developing countries by three major conditions – HIV, malaria and TB – even though these diseases infect a much smaller fraction of their populations.

This is the warning of experts who say an opportunity to rid the planet of some of its worst scourges – including sleeping sickness, elephantiasis and river blindness – is being missed because of distorted health policy goals.

"This is not the fault of pharmaceutical companies," said Professor David Molyneux of the Liverpool School of Tropical Medicine. "They have made available billions of doses of key drugs. Our problem is that we are not providing the impetus or the means for getting these drugs to disease sufferers.

"People at policy level think that only malaria, TB and HIV exist in the third world. This is not true. Neglected tropical diseases as a whole – like sleeping sickness or bilharzia – cause more of a burden than these big-name diseases but are being ignored."

Many of these diseases, such as river blindness and elephantiasis, do not kill outright but leave victims unable to fend for themselves. Others result in death, but only if left untreated for long periods. The health problems posed by these conditions will be highlighted at an international conference in Geneva this month. It will focus on neglected zoonotic diseases – ailments that are transmitted from animals. These include sleeping sickness, a parasitic disease spread by tsetse flies to humans from infected cattle. Symptoms include fever and headaches that can lead to coma and death if not treated.

"If you do not try to control sleeping sickness you can end up with horrendous epidemics," said Professor Sue Welburn of Edinburgh University, who has been working on the condition in Uganda.

"However, its symptoms are often confused with malaria. Victims are then given the wrong drugs. When those don't work, it is assumed they have HIV and they are sent home to die."

Scientists have recently found a cheaper way to deal with sleeping sickness: tackling the animals that act as reservoirs for the disease parasite.

"Animals are quite tolerant of the parasite, which exists in several different types," said Welburn. "Only one type of parasite can infect humans, however, and recently we have developed a blood test to detect it in cattle. It takes only a few hours to spot infected animals."

Once an infected herd is identified it can be treated with a drug that kills the parasite and costs 30p per animal. Reservoirs of sleeping sickness parasites can be eradicated. "So far we have treated half a million cattle in Uganda and have halted the spread of sleeping sickness," said Welburn, head of Edinburgh University's Global Health Academy, which tackles neglected diseases.

Setting up the necessary infrastructure, by combining medical and veterinary services, is proving difficult and is typical of the problems of trying to tackle neglected tropical diseases.

Other ailments, which in total affect hundreds of millions but which could be tackled cheaply and speedily, include:

■ Bilharzia. Caused by a waterborne parasite, its effects include bladder cancer, and, in children, brain damage. A single, oral dose of the drug praziquantel, once a year, can treat it.

■ Trachoma. The world's leading cause of infectious blindness and a major source of poverty. A single dose of azithromycin can treat the condition.

■ Lymphatic filariasis. Caused by roundworm, this class of disease includes elephantiasis, in which organs become swollen and distorted, and river blindness. Single annual treatments of ivermectin or azithromycin can treat these conditions. Leprosy and fasciolosis, a disease caused by flukes infecting the liver and bile ducts, could also be easily treated.

Most major pharmaceutical companies have pledged to provide, at no cost, billions of doses of the drugs needed to combat these diseases. But many G8 governments have failed to provide the means or impetus to get those drugs to the people who need them, a failure which Molyneux says is a major one.

"If we can't deliver free drugs to poor people, I don't think there is much else we can do in international health," he said.