Towards sustainable public health surveillance for enteric fever

Enteric fever that results from infection by the typhoidal Salmonellas (Salmonella Typhi and Salmonella Paratyphi A, B and C) is a life-threatening preventable illness. Surveillance of enteric fever is important to understand current burden of disease, to track changes in human health burden from increasing antimicrobial resistance and to assess the impact of efforts to reduce disease burden. Since enteric fever occurs predominantly in low income communities, expensive surveillance is not sustainable. Traditional hospital-based surveillance does not estimate population burden and intensive community-based cohort studies do not capture the severe disease that is crucial to policy decisions. While cohort studies have been considered the gold standard for incidence estimates, the resources required to conduct them are great; as a consequence, estimates of enteric fever burden have been highly geographically and temporally restricted. A hybrid approach combining laboratory diagnosis that is already being conducted in healthcare centers with community-based surveillance of health care facility use offers a low-cost, sustainable approach to generate policy relevant data.