Great news about the hostages. I hope that they all manage to recover from the ordeal which they have undoubtedly suffered.
To add a bit more on this healthcare topic in Nigeria, in one of my former companies there we had in-country health insurance with CRI. I don't think it was as good as SOS/SMI for trauma care, though I only visited 2 of their clinics. I found them to be well above the average local clinic or hospital and they seem to have either their own clinics or recommended hospitals in many cities in Nigeria (but not sure about Eket). They issue an ID card which can then be used in any CRI clinic - useful if you're travelling around and the top-end insurance with them also includes emergency medical repatriation.