To further illustrate our point, when a local pandemic is already underway, as depicted by our model, most patients who turn up at the hospitals for diagnosis are likely to have been inflicted with pandemic influenza. As such, it may be more prudent to assume positive and administer antiviral drugs without diagnosis. However, a different approach may be adopted for their contacts. From figure 5a, there is a significant increase in the amount of drugs being used when the tracing of all contacts is in place (except for policy P4b). Policy P4a uses almost 5 times more drugs than policy P2a despite reducing the total attack rate by only slightly more than half. This suggests that there is a huge amount of wastage due to the contacts. Hence, instead of applying prophylaxis to the contacts, using diagnostic testkits to identify infected contacts and treating them with antiviral drugs might then possibly yield a better attack rateto-drug usage ratio. The question then remains as to whether a fast or slow testkit makes a difference to the attack rate and drug usage. Assuming that the contacts need not go to the hospital and instead a respiratory specimen is collected and sent for analysis while the contact is ordered to stay at home (a diagnostic approach similar to D4), then a fast testkit may not be required. However, if a trip to the hospital is needed for diagnosis, the availability of a fast testkit may minimize the time the contact spends not under quarantine, preventing further spread of the influenza virus.