Abstract:
Acute rheumatic fever (ARF) and its sequel rheumatic heart disease (RHD) are serious public health problems in New Zealand (NZ), with rates similar to those in developing countries, large ethnic inequalities and little progress in control over the past 30 years. Household contact tracing is a preventative intervention that has been recommended in NZ since the 1990s on the basis of studies demonstrating the infectiousness of Group A Streptococcus (GAS) within households, but is highly resource intensive. This dissertation involved a critical appraisal of the evidence for effectiveness, appropriateness and feasibility of ARF contact tracing in NZ with a view to determining whether it should be pursued. No published studies of ARF contact tracing could be found, neither was a standardised framework for evaluating contact tracing programmes available. Therefore a set of criteria for judging an ―ideal‖ contact tracing programme were derived from the literature, with particular reference to screening programme criteria. When these were applied to ARF numerous evidence gaps were apparent. A study of ARF contact tracing at NZ’s largest public health unit (PHU) contributed valuable information, in particular demonstrating that GAS was present in the throats of 13% of household contacts, but evidence gaps still remained. According to these criteria therefore there is insufficient evidence to recommend ARF contact tracing. When other approaches to assessing the current recommendation were considered the same conclusion was reached. Urgent research is recommended to evaluate whether the benefits of the programme outweigh the costs and harms, with an initial goal of quantifying the natural secondary attack rate of ARF in household contacts. Concurrently, resources assigned to contact tracing should be diverted to other priority areas of ARF control: addressing upstream determinants, such as poverty, housing and access to healthcare, as well as optimising secondary prevention.
