Aigai virus (formerly Crimean–Congo haemorrhagic fever virus genotype VI, abbreviated to CCHFV) is an important member of the rapidly expanding Nairoviridae family of viruses in the Bunyavirales order – the cause of Crimean–Congo haemorrhagic fever (CCHF). CCHF is under surveillance at the EU/EEA level, and it is included in the World Health Organization R&D Blueprint priorities for research and product development for early diagnostics.
CCHFV is transmitted by bites from infected ticks (mainly of the Hyalomma genus) or by direct contact with blood or tissues of infected ticks, viraemic patients or viraemic livestock. Due to the involvement of ticks and vertebrates in the life cycle of the virus, and the environmental factors that influence the virus’s reservoirs, hosts and vectors, CCHF is a typical example of a disease that benefits from a One Health approach, which addresses health threats from a multisectoral perspective.
The closely related and (probably) less virulent Aigai virus (AIGV) is the prototype strain of the novel Orthonairovirus parahaemorrhagiae species within the Nairoviridae family. Currently there is no commercial molecular assay for the specific detection of AIGV, and the diagnosis is based on assays designed for CCHFV.
A new study from SHARP Joint Action partner, University of Thessaloniki | AUTH · Department of Microbiology has undertaken a study to evaluate the performance of six molecular assays for detection of AIGV which presents a potential step change in early diagnosis. Read the full article in Population Medicine an open-access, peer-reviewed scientific journal.
The importance of early detection of AIGV
CCHFV infected individuals present a variety of symptoms, ranging from asymptomatic or mild febrile illness to severe disease characterised by haemorrhagic manifestations, multiorgan failure and shock. The case fatality rate is approximately 30% among hospitalised patients. Sporadic cases and/or outbreaks of the disease have been reported in several regions of Asia and Africa, while in Europe reports have so far been restricted to the Balkan region, Spain, Russia and Turkey. It is estimated that three billion people globally are at risk of infection, and 10 000 to 15 000 infections — 500 of them fatal — occur every year. (Source: ECDC)
Currently, there is no specific antiviral drug for CCHF treatment or approved vaccine available. Therefore, prevention, early diagnosis and barrier nursing of patients are the only means to avoid viral spread. Although it was suggested that AIGV is probably less pathogenic, work with AIGV needs to take place in high containment laboratory settings.
The role of the EMERGE laboratory network
Handling CCHFV particles requires a maximum biocontainment laboratory. EMERGE – Efficient response to highly dangerous and emerging pathogens at EU level – comprises a European network with about 40 high biosafety Level diagnostic laboratories focused on risk group 3 bacteria and risk groups 3 and 4 viruses. Read more about the network and its work on laboratory preparedness and response in the EU.