Dengue After COVID-19 Vaccination: Possible and Might be Missed

Dear Editor, COVID-19 vaccination is recommended as a primary prevention of COVID-19. Data on safety and adverse effect of the new COVID-19 vaccine is very important. Of several adverse effects, thromobytopenia might occur in some vaccine recipients and immunopathological mechanism is proposed. ¹ A vaccine recipient who has vaccine -induced thrombocytopenia might have petechiae and hemorrhagic problem. Nevertheless, there might be other medical problem that leads to thrombocytopenia in a COVID-19 vaccine recipient.

A 38 years old female presented to the physician 2 days after receiving a viral vector COVID-19 vaccine. She developed myalgia, fever and skin rash and visited to a medical center. Her vital signs were as the followings: body temperature 38.5°C, blood pressure 120/80 mm Hg, pulse rate 85/min and respiratory rate 16/min. The diagnostic workup showed decreased platelet count (80 × 10³/µL). This case was firstly suspicious for a possible vaccine adverse reaction. Nevertheless, there is no coagulation profile abnormality. Since the setting is a tropical country that viral hemorrhagic disease is common, further investigation for viral hemorrhagic disease was performed. Further laboratory tests confirm that there is a positive result of dengue virus infection (Dengue NS1Ag + ve). The final diagnosis in this case is dengue. The patient receipt standard fluid replacement therapy. All of her clinical problems, including skin rash, disappeared within 1 week.

This is a case of dengue hemorrhagic fever that occurs in a patient who has just received COVID-19 vaccination for 2 days. It is a possible condition that might occur in any tropical country during the current worldwide mass vaccination. It is necessary to recognize an endemic hemorrhagic fever that might cause thrombocytopenia in a COVID-19 vaccine recipient. This clinical problem might be missed diagnosed as an adverse event of vaccine. A coincidence of fever following COVID-19 vaccine and endemic tropical disease is a possible emerging problem in the present day. The present case is a good example and practitioner should aware of this scenario when dealing with post-vaccination thrombocytopenia problem.