A 30-year-old traveller returns from Sri Lanka with a 5-day history of fever, severe arthralgia affecting the hands and ankles, and a widespread macul...

Question

A 30-year-old traveller returns from Sri Lanka with a 5-day history of fever, severe arthralgia affecting the hands and ankles, and a widespread maculopapular rash. Platelet count is 135 × 10⁹/L (mildly reduced). IgM serology is positive for both dengue and chikungunya. How should the clinician interpret these results?

Accepted Answer

Serological cross-reactivity between dengue and chikungunya IgM is well-recognised, and PCR should be performed to confirm the causative virus

Answer

The patient has concurrent dengue and chikungunya co-infection

Answer

The positive dengue result is most likely due to serological cross-reactivity between flaviviruses and alphaviruses and does not indicate dengue co-infection

Answer

Both results are false positives and should be disregarded

Answer

The chikungunya result is a false positive; only dengue is present

uk-dtmh MCQ (SBA): Dengue-Chikungunya Serological Cross-reactivity