"Nathan travels to the end of the road where wild animals and people meet and tries to get one step ahead in the process, " says Google.org director Frank Rijsberman.

FORBES: Nathan Wolfe chases killer microbes.

According to a study by Frank Rijsberman, director-general of the International Water Management Institute in Colombo, Sri Lanka, improving the delivery of clean water and sanitation to the poor would be a highly cost-effective way to use additional aid to developing countries.

ECONOMIST: Economics focus