The tick was not infected with CCHF.
INVASIVE TICK - UK: (ENGLAND)
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A ProMED-mail post
A tick capable of carrying a host of killer illnesses has been found
in the UK for the very 1st time, health officials have revealed.
The _Hyalomma rufipes_ tick - a small blood-sucking arachnid - is
usually confined to Africa, Asia and parts of southern Europe. But
Public Health England [PHE] has now revealed one of the ticks, 10
times larger than others, was discovered in Dorset last year [2018].
The creature itself wasn't found to be carrying the deadly
Crimean-Congo Haemorrhagic fever virus (CCHF).
The disturbing find, which could 'present a threat to public health in
the UK', has been documented in the journal Ticks and Tick-borne
Diseases.
A vet at The Barn Equine Surgery in Wimborne removed the tick from a
horse last September [2018]. They then sent it to PHE's tick
surveillance team. Writing in the journal, the PHE team said: 'This is
the first time _Hyalomma rufipes_ has been reported in the United
Kingdom. 'The lack of travel by the horse - or any in-contact horses -
suggests that this could also be the 1st evidence of successful
moulting of a _Hyalomma_ nymph in the UK.'
The team of researchers who found the tick was led by Kayleigh
Hansford, of PHE's medical entomology and zoonoses ecology group.
Writing in the journal, they said it is suspected the tick hitched a
ride on a migratory bird before landing in the UK. Neither the
infested horse, nor other horses in the stable had travelled anywhere
and no further ticks were detected on any of the horses. It is thought
the tick travelled on a swallow because they are known to nest in the
stables of horses and migrate from Africa to the UK for summer.
The UK climate, known to be getting warmer, is thought to be a major
limiting factor for the survival of _Hyalomma rufipes_. However, the
unusually warm weather experienced during the summer of 2018 may have
been a factor for helping it moult - become an adult.
Currently, the ticks are found in Greece, Northern China, Russia,
Turkey, Iraq, Syria, Pakistan, Egypt, Yemen and Oman.
The World Health Organization last year [2018] named CCHF as one of 10
pathogens that pose the most 'urgent' threat to humanity.
Figures show the virus - most often spread through tick bites - kills
around 40% of humans that it strikes. The horrific illness is said to
manifest 'abruptly', with initial symptoms including fever, backache,
headache, dizziness and sore eyes.
[Byline: Stephen Matthews]
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Communicated by:
ProMED-mail Rapporteur Mary Marshall
[Not mentioned in detail in the above report, the PHE team, using
morphological and molecular methods, then tested for a range of
tick-borne pathogens including: Alkhurma virus, Anaplasma, Babesia,
Bhanja virus, Crimean-Congo Haemorrhagic fever virus, Rickettsia and
Theileria. The tick tested positive for _Rickettsia aeschlimannii_, a
spotted fever group rickettsia linked to a number of human cases in
Africa and Europe (reference below).
The critical question is if this is a single tick transported into
Dorset, or represents one tick of a local breeding population.
Transportation of a single tick by a migrating bird is a reasonable
possibility. Immature (nymph) _Hyalomma_ usually feed on birds,
rodents, and hares. Nymphs are often transported from one place to
another by migrating birds. For example, a migrating bird carrying a
CCH virus-infected _Hyalomma marginatum_ nymph can introduce the virus
into new localities and infect humans and domestic livestock (Larry
S.Roberts, 2009). Continued surveillance in the area where the single
tick was found, as well as generally in the UK over the spring and
summer months, would be prudent.
References ---------- Hansford KM, Carter D, Gillingham EL, et al. _Hyalomma rufipes_ on an untraveled horse: Is this the first evidence of Hyalomma nymphs successfully moulting in the United Kingdom? Ticks Tick Borne Dis. 2019;10(3):704-708. doi: 10.1016/j.ttbdis.2019.03.003. PMID: 30876825
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