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CRIMEAN-CONGO HEMORRHAGIC FEVER - BULGARIA: (KURDZHALI)

Two cases of Crimean-Congo hemorrhagic fever (CCHF), the latter reported yesterday [27 Jun 2013], were admitted to the Infectious Disease Department of "Dr. Atanas Dafovski" Hospital in Kardzhali. Both were referred for treatment to the Plovdiv Hospital, as the 1st hospital lacked facilities to treat contagious diseases such as CCHF, according to the head of the department, Dr. Magdalena Marinova.

The patients had been bitten by ticks, which disseminated the disease. This year [2013], the [tick] population is particularly high due to periods of heavy rainfall. According to Dr. Marinova, people bitten by a tick should immediately seek medical attention and not try to remove the tick themselves because of the risk of the tick remaining attached to the patient's body.

The [initial] symptoms of Crimean-Congo hemorrhagic fever can be treated with hyper-immune gamma globulin, but if the disease is in an advanced stage, there is risk of death, warned Dr. Magdalena Marinova. In practice, over 15 percent of Crimean-Congo hemorrhagic fever patients do not recover.

Communicated by: ProMED-mail

Crimean-Congo hemorrhagic fever is caused by infection with a tick-borne virus (belonging to the genus _Nairovirus_ of the family _Bunyaviridae_. The disease was 1st characterized in the Crimea in 1944 and given the name Crimean hemorrhagic fever. It was then later recognized in 1969 as the cause of illness in the Congo, thus resulting in the current designation of the disease. Crimean-Congo hemorrhagic fever is found in Eastern Europe, particularly in the southern parts of the former Soviet Union. It is also distributed throughout the Mediterranean, in northwestern China, central Asia, southern Europe, Africa, the Middle East, and the Indian subcontinent.

The following information has been extracted from a recent review in The Lancet :

In its immature form, the tick feeds on small mammals. Later, the adult tick attaches itself to cattle, sheep, goats, or human beings. Livestock show no overt signs of disease, and farmers and slaughterhouse workers have little idea they have been infected until they start expressing symptoms: dizziness, muscular pain, and stiffness, and of course the signature bleeding. Whereas infection in birds mostly tends to be abortive, ostriches are important hosts. In the mid 1990s, South Africa saw a CCHF outbreak at an ostrich abattoir. About 30 countries in Africa, Asia, and Europe have reported CCHF. The tick ventures no further than 50 degrees north latitude, which cuts across Russia, Ukraine, central Europe, and France; the latter 2 regions are not considered to be at any immediate risk. The _Hyalomma_ spp. ticks are present, but there is no serological evidence of CCHF. Changing patterns of agriculture and flood control may also have played a part. In Turkey, affected parts of central Anatolia had been more or less abandoned in the late 1990s due to terrorist activity. Hunting and farming resumed in 2001, and ticks were able to fasten onto the influx of cattle and sheep. The following year [2002], Turkey confirmed its 1st case of CCHF, and numbers have steadily increased ever since (which may simply be due to the increased surveillance). Only 4 countries report more than 50 cases per year: Iran, Russia, Turkey, and Uzbekistan (although it could easily be the case that these countries simply have particularly efficient surveillance systems backed by proper diagnostics). There is a good deal unknown about the vector, the virus, and its spread. Variation in mortality is just one of these issues; it could be related to the alacrity with which supportive therapy and treatment are started, but viral properties (there are several distinct strains of CCHF virus) and genetics may also play a part.