The names alone conjure up an image of plagues from some ancient civilization: river blindness, snail fever, elephantiasis. But they are very much alive in the 21st century as the most common neglected tropical diseases.

They are 13 parasitic and bacterial infections that affect over 1.4 billion people, mostly the poorest. In Liberia, almost three quarters of the population needs treatment. Elephantiasis, a painful, disfiguring disease, affects 120 million people in 80 countries, all of them very far from pristine alpine hamlets like Davos.

But one change apparent in Davos during this recessionary age: appeals for money come with more facts about what results they buy, a focus on investors' zeal for profits: if they can't get them in the markets, maybe they'll appreciate them in the field.

"For governments, corporations, NGOs and individuals, there is little else during this global economic crisis that provides such a significant return on investment while also reducing suffering and saving lives," Melinda Gates said today. The Bill and Melinda Gates is giving $34 million to the Global Network for Neglected Tropical Diseases.

Treating seven of the most common neglected tropical diseases costs about 50 cents per person a year, she said. Investments in controlling such diseases "are reaping significant dividends."

A $3.6 million investment over five years can buy treatment for 75 percent of Liberia's population.

Promoting these "penny cures" is one way to attract business partners, along with reminders about how much more productive people are when their limbs and intestines aren't swollen with worms.

In fact the Global Network has created a neglected tropical disease "investment book," mapping out the health and monetary benefits gained when an individual or corporation makes a specific investment, which Gates assigned as homework for world business and government leaders.

Neglected tropical diseases -- trachoma (eye infections), soil-transmitted helminths (hookworm, Ascaris, Trichuris), onchocerciasis (river blindness), schistosomiasis (snail fever) and lymphatic filariasis (elephantiasis) -- are not only debilitating, but they also result in "billions of dollars of lost productivity," says the foundation.

Evidently the focus on money is working. The Global Network said that several major corporations, private donors, and international organizations have made new commitments to the campaign to end neglected tropical diseases by 2020, including Accenture, GlaxoSmithKline (GSK), Merck, Pfizer, the Inter-American Development Bank, and the Hoffman Fund.