Informed Consent Procedure: The volunteers will be screened using a questionnaire (see attached). The language of communication will be English or a local language used by the community. Researchers will explain to the volunteers on an individual basis, the nature of the study, what would be expected of them and their rights. Volunteers may choose to drop out of the study at any time without any restrictions. Volunteers will be informed that the screening procedure also includes physical examination and laboratory test. Following informed consent, using Consent to Participate Form (see attached) and counseling, volunteers may be enrolled for the study.