Measles elimination has been on the World Health Organization agenda for the last fifteen years. Progress towards elimination has been made. However, it has not been uniform around the world. On the African continent, the vaccine coverage rate is the lowest in the world and the disease burden is the highest. While poliomyelitis is almost eradicated from the continent, there are countries such as Mozambique where complete measles control is still not a reality. The maternal antibodies that children have acquired prior to birth protect them from measles during the first months of life. The period of time from when the child loses protection from maternal antibodies until a protective level of antibodies following vaccination has been acquired is known as the window of susceptibility for acquiring measles. | In low-income countries, where exposure to measles virus is high and the decline in protective maternal antibodies is rapid, infants are at high risk of acquiring measles before they are eligible for vaccination. Pre-vaccine measles is associated with high mortality. To decrease infant mortality in resource-poor countries with high levels of measles virus circulation, World Health Organization suggests that the measles vaccine is given at nine months of age. This is contrary to high-income countries where measles vaccine is given based on information obtained through sero-surveillance of infants” immune status. The recognition of such challenges and the need for a simple approach to estimate the window of susceptibility for measles among infants living in resource-poor settings inspired the work included im this thesis. The thesis is based on three cross sectional surveys and one retrospective data review conducted in different regions in Mozambique during 1998-2005. A combination of epidemiological, social and biological survey techniques was used. The results contribute to both Health Information System and the Public Health domains. Specific recommendations to strengthen the measles surveillance system mn Mozambique and to integrate vaccination data into disease surveillance are presented.

The key contributions include:

The identification of the challenges that the measles surveillance system must address in order to play a functional role in public health interventions. Furthermore, the need for to create a vaccine data base based on individuals at the health facility has been highlighted. There is a need in resource-poor settings to integrate different data sets that serve to monitor infectious diseases in order to increase the effectiveness of the health system. This thesis also proposes a simple framework by which the “window of susceptibility" can be estimated based on sets of existing data.