Various conditions from which Chikungunya fever must be distinguished are listed in Table 3. Twin outbreaks of dengue fever and Chikungunya fever are known to occur frequently.[40] While it is virtually impossible to distinguish one of these conditions from another on clinical grounds, observations published by astute clinicians can be of some help. In a study published from Thailand,[76] it was reported that compared with patients with dengue hemorrhagic fever, subjects with Chikungunya fever were more likely to manifest arthralgia/arthritis, maculopaular rash, and conjunctival injection. However, laboratory testing is essential to distinguish Chikungunya fever from the other conditions.