Olivia Nalweyiso has three children—“and no more,” the 32-year-old Ugandan firmly declares. Nalweyiso lives in a fishing community on the banks of Lake Victoria. Large families are the rule here, but ­Nalweyiso has deliberately made herself an exception.

Since 2009, she has been learning about all kinds of health topics—from family planning to the importance of vaccinations—through the Dutch ­development organization Text to Change. Twice a month, Nalweyiso receives a text message with a quiz. As soon as she answers, Text to Change sends her more information. The free service also encourages recipients to visit the ­nearest clinic for checkups. “That’s how I’ve learned about different birth control methods,” says Nalweyiso, “and that it’s a good idea to think about how many children you want to have.”

Many developing countries suffer from a lack of medical knowledge and health education. The result: People with HIV don’t know that they must take their ­medicine every day; parents have no idea how to prevent the malaria that kills their children. “Text messaging is a powerful means of communication that can help spread this kind of information,” says Bas Hoefman, Text to Change’s director. “Text messages are cheap and interactive. Moreover, the technology is simple—any cell phones can send and receive text messages.” The organization, with an office in the Ugandan capital, Kampala, is currently running about 50 educational campaigns in Africa and South America on health themes, education and the environment. Campaign response is usually high.

Nalweyiso also consults the health clinic more often. She’s not alone. An awareness campaign about HIV and AIDS in Uganda recently doubled the number of people getting tested for HIV. As for Nalweyiso, Text to Change can’t send her enough messages: “The more I can learn, the better my life and that of my family will be.” | Find out more: texttochange.com