Viral flu / Dengue / Chickengunya / Typhoid / Cough Viral flu, dengue, chikungunya, typhoid, and cough can all have similar symptoms, making it difficult to diagnose them on your own: Viral flu Also known as influenza, this contagious respiratory illness can cause mild to severe illness, and sometimes death. The best way to prevent the flu is to get a flu vaccine each year. Dengue A viral illness that can cause a high fever lasting four-five days, followed by joint and muscle pain, fatigue, nausea, vomiting, and skin rash. Dengue is spread by mosquitoes, and you can reduce your risk by avoiding mosquito bites, using insect repellent, and covering exposed skin. Chikungunya A viral illness that's spread by infected mosquitoes, and causes severe joint pain, fever, and rash. There's no specific treatment for chikungunya, but you can prevent it by avoiding mosquito bites and eliminating mosquito breeding sites. Typhoid A life-threatening bacterial infection that's usually spread through contaminated food or water. Cough A symptom of COVID-19, which can also cause shortness of breath, loss of taste or smell, sore throat, congestion, or runny nose.