A pilot program for clinical Q fever surveillance as a first step for a standardized differential diagnosis of abortions: Organizational lessons applied to goats farms

摘要

Multiple challenges have to be faced both for animal and public health in the fields of infectious abortion surveillance especially when zoonotic diseases are concerned: ensuring early detection of brucellosis, improving outbreak surveillance as well as animal health management. Thus, a global approach to diagnosis of abortive infectious diseases was discussed within the framework of the French platform for animal health surveillance by a collaborative multi-stakeholder group. Q fever appeared as a relevant target to initiate this new approach in order to test the different steps, from the implementation in the farms to the analysis of the results. Therefore, a pilot study was set up in 2012, for three years, in ten departements (administrative unit of 5500 Km2 on average) covering 1493 goat farms. It focused on abortive episodes defined as at least three abortions over seven days or less. A farm-level diagnosis approach, i.e. the interpretation of combinations of results from several animals was used. Therefore, the decision-making was based on the results of two qPCR applied on vaginal swabs (individual or pooled analysis) and, if necessary, on further serological analyses, taking account of the vaccination status of herds. The National Reference Laboratory had a key role as it was involved in validation and harmonization of the analytical process. A total of 114 abortive episodes from 105 goat farms were investigated. Among them, 16.7% were considered due to Q fever (related herds considered as "clinically affected" according to EFSA recommendations: 18.1 %). Between the eight departements where goat farms had notified series of abortions, the proportion of abortive episodes attributed to Q fever varied greatly from 0% to 36.4%. In addition to reinforcing knowledge about Q fever, this study enabled obtaining useful field feedbacks on feasibility and acceptability of such surveillance programs before extension to other abortive infectious agents and to the whole territory.