Crimean-Congo haemorrhagic fever, symptoms and control

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Now-a- days many of cases of Crimean-Congo haemorrhagic fever (CCHF) are being reported in

different cities of Pakistan. Crimean-Congo haemorrhagic fever (CCHF) is primarily an animal

disease; however, sporadic cases and outbreaks of CCHF have also been reported in humans.

Crimean-Congo hemorrhagic fever is caused by Crimean-Congo hemorrhagic fever virus

(CCHFV). This virus is a member of the genus Nairovirus in the family Bunyaviridae. It belongs

to the CCHF serogroup. Although early serological studies revealed very few differences

between strains of CCHFV; however, nucleic acid sequence analysis has demonstrated extensive

genetic diversity, particularly between viruses of different geographic regions.

The virus was first isolated in Pakistan (Changa-Manga forest), in 1960s from ticks while the

first case was reported in Pakistan in 1976 in Rawalpindi when a physician treating a patient with

abdominal pain, melena and hematemesis at the Central General Hospital now named Benazir

Bhutto Hospital. In addition, an operation theatres attendant also died while attending that

patient. Another outbreak was stated in December 1994 in Baluchistan (Quetta) which resulted in

death of the patient. Two surgeons who were operating on him also found infected with the virus

along with a health care personnel at Agha Khan University Hospital, Karachi, where these

surgeons were being treated.

On the evening of 7th December 2005, a 32 years old previously healthy man was admitted to

the Combined Military Hospital, Abbottabad. He belonged to a family which owned butchery

and barbeque shop. Within 24 hrs of hospital admission he died because of multi-organ failure.

His blood PCR was positive for CCHF virus. According to National Institute of Health (NIH)

report, in2015, at least 25 CCHFV positive patients in critical condition from Peshawar, Dir,

Kohat and Swabi were brought to Hayatabad Medical Complex and out of them, 11 died. The

most notable point in different outbreak cases remained its transmission.


The virus is transmitted to humans through the bite of an infective adult tick of the genus

Hyalomma, and even crushing an infected tick also causes infection by skin lesions. It was

observed that besides person to person transmission; there are some additional factors, including:

infected blood and tissues of animals, bloody vomit and body fluids of humans. The injections

and surgical procedures in hospitals may also play a vital role in spreading the disease.

Therefore, those professions which deal with infected animals and humans such as livestock

breeders, abattoir workers and healthcare workers are at high risk to this disease. Mass scale

animal movements anticipated prior to Eid-ul- Azha could serve as a source of propagation for

ticks infested with CCHF virus thereby increasing the risk of disease transmission, which require

possible control measures.

Incubation Period

The incubation period is influenced by the route of exposure. Infections acquired via tick bites

usually become apparent after 1 to 3 days; the longest incubation period reported by this route is

nine days.

Clinical Signs

The first sign of Crimean-Congo hemorrhagic fever is a sudden onset of fever and other

nonspecific symptoms including chills, severe headache, dizziness, photophobia, neck pain,

myalgia and arthralgia. The fever may be very high. Gastrointestinal symptoms including

nausea, vomiting, non-bloody diarrhea and abdominal pain are also common. Sharp mood

changes, confusion and aggression have been reported in some cases. Cardiovascular changes

such as bradycardia and low blood pressure can also occur. This early stage of disease is called

the pre-hemorrhagic phase. It is followed, after several days, by the hemorrhagic phase. Other

symptoms including sweating, dryness of the mouth, headache, dizziness, nausea, poor appetite,

labored breathing, polyneuritis, poor vision, loss of hearing, and memory loss have also be seen.

Some patients temporarily lose all of their hair. Hepatorenal insufficiency has also been reported

in some countries.. Recovery is usually complete but slow, and can take up to a year.

Diagnostic Tests

CCHF can be diagnosed by isolating virus from blood, plasma or tissues. The virus is most

likely to be found in the lung, liver, spleen, bone marrow, kidney and brain. CCHFV can be

isolated in a variety of cell lines including SW-13, Vero, LLC-MK2 and BHK-21 cells. Cell

cultures can only detect high concentrations of the virus, and this technique is most useful during

the first five days of illness. CCHFV is identified by indirect immune fluorescence or reverse

transcription-polymerase chain reaction (RT-PCR) assays. Virus isolation must be carried out in

maximum bio-containment laboratories (BSL-4).

Treatment and control

Treatment is mainly supportive, however: Ribavirin is a drug that is used in some cases.

Observational studies in humans and studies in experimentally infected mice support the use of

this drug; however, no randomized human clinical trials have been published. Several drugs

including: Negawan ,Separmethrin, Deltabak and Ivermectin are also being used to control ticks.

As, this is an emerging disease and transmit through a vector, therefore, it requires a considerable

notice at government and public health departments e.g. proper insecticidal spray on animals and

premises, routine hematological screening of animals and their owners, use of gloves and mask

while purchasing and sale of animals. By proper hygienic and control measures, especially in

meat markets and where animals are brought to sale (Bakra Mandi), it is possible to manage its



Published in: Volume 07 Issue 30

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