King Chwan-chuen cites as a case in point the dengue fever epidemic of 1988. Because front-line doctors could not see any clues, when extended treatment failed to make any improvement, cases were turned over to Mackay Memorial hospital. When Mackay diagnosed the illness as dengue fever, it had already been spreading through eastern Pingtung for several months.
金傳春舉民國七十七年的登革熱流行為例，由於第一線醫師看不出什麼端倪，病患久治不愈轉到馬偕醫院求診，馬偕醫師診斷出是登革熱時，登革熱已在屏東東港地區流行了好幾個月。