In the battle for the billions of dollars spent fighting global diseases, doctors who tackle neglected tropical diseases have labeled their struggle a “best buy.”

In a report issued in June, a consortium called United to Combat NTDs argued that every $1 invested in fighting tropical diseases would generate $50 to almost $200 in productivity gains by 2030.

The consortium’s targets include sleeping sickness, guinea worm, Chagas, river blindness, trachoma, elephantiasis, leprosy, leishmaniasis, bilharzia and intestinal worms picked up in food or from the soil.

Not all of these diseases kill, but all can make victims so sick, weak or crippled that they are unable to work or attend school. So many patients lose so many work and school days, the report’s authors argued, that the total economic burden may be as great as that caused by better-known killers like AIDS and malaria.

Also, most of these diseases can be fought relatively cheaply with simple measures like window screens, insecticide spray, water wells, deworming drugs, antibiotics — even, in the case of trachoma, with soap and water.

Pharmaceutical companies have agreed to donate almost $18 billion worth of drugs to the fight over the next five years, the report said. Health ministers in 26 affected countries — led by Bangladesh, the Philippines and Honduras — have agreed to take responsibility for funding all or most of their national campaigns.

The campaign still needs $300 million in donations by 2020, partly for research into better diagnostics, but mostly just to get the solutions to the remote villages where most affected people live, the report said.