Introduction: Areas where leptospirosis and arboviruses are endemic largely overlap in the tropics. However, the number of arbovirus infections is usually much higher. The initial clinical presentation can be highly confusing; therefore, laboratory confirmation is key to an accurate diagnosis.
Case presentation: A 19-year-old man presented to a peripheral health centre with an acute febrile illness. Dengue was initially suspected, but the patient deteriorated to a shock syndrome. Leptospirosis as well as a co-infection with Zika virus were both confirmed in the laboratory, the latter being clinically masked in this dual infection.
Conclusion: This case highlights the importance of not only considering the differential diagnosis of acute febrile syndromes, but also to consider the possibility of dual infections in the context of global spread of arboviruses. The specific context of travellers returning from endemic areas and pregnant women is also highlighted and discussed.
Keywords: amoxycillin; differential diagnosis; dual infection; leptospirosis; shock syndrome; zika virus.