Some of the outfitters who work down there recommend :
tetanus, hepatitis A, typhoid, yellow fever, and anti malarial drugs. I went two years ago and followed their advice. Its a wallop ~$300 at least where I am. And you have to get them ahead of time. BUT, I simply did not want to mess with the risk of yelllow fever and typhoid. HEPATITIS, sadly to say is a risk we take when surfing close to Mexico, *$&^@^# & once you have it, your liver is basically shot.
KJ
I DID not take the anti-malerial drugs, though like the previous poster, I was mosquito bit to hell. No malaria, but I wish I would have packed AND WORN some light tights on my legs in certain areas of Ec.
But enjoy it!
Other than the rivers, btw, one of the coolest things I did was a trip to an 'indigenous market' in Guamote, near the Volcan Chimbo, sort of. Only saw 3 gringos the day we were there. Thursdays, south of Riobamba.