Crimean-Congo haemorrhagic fever (CCHF), reported to cause “bleeding from the eye”, has spread from endemic countries in Africa, Asia, the Middle East and the Balkans, to Spain. The virus is usually carried by ticks and livestock and passed on to humans through bites.
Associate Professor Nicole Carnt, from the University of New South Wales (UNSW) School of Optometry and Vision Science, says there is little reason for concern in Australia.
It is likely “bleeding from the eye” is describing these sub conjunctival haemorrhages, which we know look quite alarming but resolve without sequalae
“As a blood borne virus, transmission between humans occurs only via infectious blood or body fluids, so is extremely rare, unlike for respiratory conditions like SarsCov-2. Due to the distance from endemic countries and the strict border restrictions in Australia, the chance of infected ticks or animals arriving on shore is very low. If this did occur, the risk to humans would be for farm workers, and protective measures can be taken,” said A/Prof Carnt.
Referencing a Turkish study that describes the ocular findings of patients with CCHF,1 A/Prof Carnt says, “ocular manifestations occur in approximately 70% of cases, mostly conjunctival hyperaemia, but visual symptoms are rare.
“In that study, around 30% of patients had multiple sub-conjunctival haemorrhages, and around 10% had retinal haemorrhages. However, within one month these were mostly reabsorbed.
“It is likely that ‘bleeding from the eye’ is describing these sub conjunctival haemorrhages, which we know look quite alarming but resolve without sequalae. It is unlikely that this would be a presenting complaint, given the severe systemic disease.”
The Turkish study concluded that “CCHF caused a mild form of ocular disease…[and] must be considered when subconjunctival or superficial retinal haemorrhages are seen in association with fever in endemic areas.”1
The latest scare comes after the hospitalisation of a man in Leon, in northwest Spain, who was in a stable condition at the time of reporting. Other symptoms of CCHF include fever, aches, dizziness, mood swings and confusion.
- Engin, A et al. 2009, Ocular Findings in Patients with Crimean-Congo Hemorrhagic Fever, American Journal of Ophthalmology, Vol. 147, Issue 4, P634-638.E1, https://doi.org/10.1016/j.ajo.2008.11.014.