Biometric markers are ideal for use as identifiers because they are unique and unchanging over time. But that also makes them very vulnerable. If these identifiers are compromised, the potential consequences for victims in terms of loss of privacy and security are severe. If my password is compromised I can change it, but I'm stuck with my fingerprints, eyes and other physical characteristics.
It is easy to see the benefits of biometrics as a supplement, and perhaps even a replacement, to traditional identification measures. Biometric factors of identity cannot be lost or forgotten, they are things that everyone carries around with them at all times
I'll leave it to biometrics companies to defend fingerprints in general (there are arguments on grounds of reliability, cost etc that carry some weight) and save my own opinions on biometrics as credentials for another day.
Health workers in developing countries face challenges that are often taken for granted in the developed world, but new technologies have the potential to become leap frog solutions that address such barriers.