Reliable Serological Testing for the Diagnosis of Emerging Infectious Diseases

Climate change, increased urbanization and international travel have facilitated the spread of mosquito vectors and the viral species they carry. Zika virus (ZIKV) is currently spreading in the Americas, while dengue virus (DENV) and chikungunya virus (CHIKV) have already become firmly established in most tropical and also many non-tropical regions. ZIKV, DENV and CHIKV overlap in their endemic areas and cause similar clinical symptoms, especially in the initial stages of infection. Infections with each of these viruses can lead to severe complications, and co-infections have been reported. Therefore, laboratory analyses play an important role in differential diagnostics. A timely and accurate diagnosis is crucial for patient management, prevention of unnecessary therapies, rapid adoption of vector control measures, and collection of epidemiological data.There are two pillars to diagnosis: direct pathogen detection and the determination of specific antibodies. Serological tests provide a longer diagnostic window than direct methods, and are suitable for diagnosing acute and past infections, for disease surveillance and for vaccination monitoring. ELISA and indirect immunofluorescence test (IIFT) systems based on optimized antigens enable sensitive and specific detection of antibodies against ZIKV, DENV and CHIKV in patient serum or plasma. In recent years, Euroimmun (Lübeck, Germany) has developed numerous test systems for the serological diagnosis of (re-)emerging diseases, including a very sensitive and specific anti-ZIKV ELISA.