Figure 3. The impact of using each diagnosis strategy, for different presentation rates of mild cases ().

As mild-presentations constitute the bulk of all symptomatic infections, if only a small percentage of them present to outpatient facilities, then an intervention (based on any diagnostic strategy) is unable to control the epidemic. If approximately one in three or more mild cases presents, then there is a non-negligible chance that an epidemic may be controlled given an appropriate diagnostic strategy is employed. The probability of control rises rapidly with the proportion of mild cases that presents. Maximal impact is achieved with the PCR and PCR/Syndromic strategies. A syndromic strategy is less effective. The POCT strategies have negligible impact (the curves lie on the horizontal zero axis).