Adherence has been defined as the active, voluntary, and collaborative involvement of the patient to establish treatment goals and the medical regimen. In case of infectious disease treatment, medication adherence success is not only for helping patient's health, but also one of the essential points of the prevention of new infections in the population. The purpose of this study is intended as an investigation of factors for promoting adequate drug taking behavior of elderly persons in some local communities in Africa and in Japan. The goal of this study is to contribute to the practice of effective infectious disease control targeting the vulnerable groups including the poor and the elderly. High levels of drug adherence have been reported in studies conducted in sub-Saharan Africa, despite the fact that quality of health service in the region is often limited. This can be explained in terms of daily encouragements by the patient's family and the community members who are considerably concerned about the patient's health. In contrast, health experts in Japan often face difficulty in maintaining the adherence of tuberculosis control in the single and poor elderly population. In this study, I would like to analyze adherence of elderly people by examining patient's social relations by using the medical-anthropological methods. The fieldwork will be accomplished in a village of the Eastern province of Zambia, and in Nishinari area of Osaka city, Japan. At the end of this study, I intend to hold a dissemination seminar and discussions with NGOs and medical staff working on issues related to infection control and health of the aging.