Authors’ reply: Comment on: definitive tests for dengue fever: when and which should I use? [1]

Dear Sir,

We thank the authors for sharing their ideas and experiences(1) in response to our article.(2) Regional perspective is important, given the increasing air travel in the world today. We agree with the authors that clinical diagnosis is the mainstay approach for diagnosis of dengue. Singapore’s clinical practice guidelines have also adopted clinical criteria for suspected cases of dengue fever.(3) Definitive diagnostic tests are important adjuncts for confirmation of a dengue infection and managing clinical uncertainties.(3) Dengue immunoglobulin M serological tests are useful in the later stages of the illness, while NS1 antigen tests allow the infection to be confirmed in the early stages, hence enabling timely environmental vector control and vector-bite prevention measures, as well as appropriate clinical plans for the monitoring of patients with negative confirmation tests.

In Singapore, we noted a significant reduction in dengue cases in 2017.(4) The lower proportions of dengue cases compared to similar mosquito-borne diseases such as Chikungunya and Zika(5) might make it harder for physicians to differentiate between the conditions, thus increasing the importance of definitive diagnostic tests. The abrupt change in the prevalence of dengue cases prompted our article, which aimed to alert primary care practitioners of the need to adjust their clinical diagnostic threshold and select the appropriate adjuncts. Vector control remains an important measure that should be continued. A coordinated regional effort might be beneficial to eradicate mosquito-transmitted diseases in Southeast Asia.

Yours sincerely,