NSW Estimated dissemination rate

The estimated dissemination rate (EDR) for a disease is the average number of new cases generated by each existing case. An EDR of greater than 1 indicates that the disease will continue to spread and the epidemic will continue. Conversely, an EDR of less than 1 means that the epidemic will gradually die out. The graph below shows that the EDR for horse flu has progressively declined since about mid September and has been below 1 for most of the time since early October. The dotted lines show the 95% confidence limits for the estimate. The slight ups and downs of the EDR over time are probably due to variations in reporting over time. Although the EDR estimates are probably affected by some under-reporting, the graph provides strong encouragement that the disease is under control and eradication is achievable.