How is the source of food poisoning outbreaks established? The example of three consecutive Salmonella enteritidis PT4 outbreaks linked to eggs.

Three consecutive outbreaks of Salmonella enteritidis PT4 occurred in Wales in 1989 in which epidemiological and microbiological investigation established eggs as the likely source although kitchen inspection and food preparation histories suggested other vehicles of infection. This paper examines the contribution of analytical epidemiology in attributing causation, with particular reference to those limitations which are regarded as inherent in epidemiological evidence. Such evidence, implicating eggs in the three outbreaks, fulfilled 6/7 widely accepted criteria for causation; data to assess the seventh were lacking. Collaboration between different agencies and professionals in investigating outbreaks is very important.

Attitudes to follow-up after uncomplicated surgery--hospital out-patients or general practitioner?

The attitude of 216 patients, 10 hospital doctors and 80 general practitioners (GPs) to hospital follow-up after uncomplicated surgery for non-malignant disease was assessed. Hospital doctors felt that most patients (86%) could have been satisfactorily followed-up by their GP and in most cases (89%), the GP was willing to provide the service. However, 183 patients (85%) found their visit to hospital out-patients worthwhile and only 41 patients (19%) would have preferred to have visited their GP instead. In fact, 157 patients (73%) had already seen their GP before their return to surgical out-patients. In most cases, hospital follow-up appears to be unnecessary. In this series, if suitable post-operative patients were followed-up by their GP, there would be a reduction of 20% in the number of old patients returning to out-patients.