All his life Jasper Lawrence suffered horrendous allergies and asthma. On some days he could feel his eyes literally squeaking in their sockets from inflammation. So when he saw a documentary about how hookworms could help asthma sufferers, he decided to investigate. The good news was that there was a link. The bad news was that the only way to get hookworms was through contact with human faeces in a developing country. So Jasper set out to infect himself by walking through open air latrines in Cameroon.