Date: Tue 22 May 2018
Source: Tehran Times [edited]
Since the beginning of the current Iranian calendar year [21 Mar 2018], 10 cases of Crimean-Congo haemorrhagic fever [CCHF] have been reported, director of the Health Ministry's communicable diseases control department has said. "Out of the 10 reported cases unfortunately one has passed away," ISNA news agency quoted Mohammad Mehdi Gouya as saying on [Tue 22 May 2018]. The disease outbreak normally occurs in spring and it becomes more severe with the beginning of the livestock breeding season, Gouya said, adding that every year some 100 to 150 cases of Crimean-Congo haemorrhagic fever are reported in Iran. The family members and healthcare providers are trained to avoid catching the virus, he concluded.
According to World Health Organization (WHO), CCHF is a widespread disease caused by a tick-borne virus. CCHF is endemic in Africa, the Balkans, the Middle East, and Asia, in countries south of the 50th parallel north. The CCHF virus causes severe viral haemorrhagic fever outbreaks, with a case fatality rate of 10-40 percent. There is no vaccine available for either people or animals. The hosts of the CCHF virus include a wide range of wild and domestic animals such as cattle, sheep, and goats. The CCHF virus is transmitted to people either by tick bites or through contact with infected animal blood or tissues during and immediately after slaughter. The majority of cases have occurred in people involved in the livestock industry, such as agricultural workers, slaughterhouse workers, and veterinarians. Human-to-human transmission can occur resulting from close contact with the blood, secretions, organs or other bodily fluids of infected persons. Hospital-acquired infections can also occur due to improper sterilization of medical equipment, reuse of needles, and contamination of medical supplies.
Onset of symptoms is sudden, with fever, myalgia (muscle ache), dizziness, neck pain and stiffness, backache, headache, sore eyes, and photophobia (sensitivity to light). There may also be nausea, vomiting, diarrhea, abdominal pain, and sore throat early on, followed by sharp mood swings and confusion. After 2 to 4 days, the agitation may be replaced by sleepiness, depression, and lassitude, and the abdominal pain may localize to the upper right quadrant, with detectable hepatomegaly (liver enlargement). General supportive care with treatment of symptoms is the main approach to managing CCHF in people. Additionally, the antiviral drug ribavirin has been used to treat CCHF infection with apparent benefit. Death normally occur in the second week of illness. In patients who recover, improvement generally begins on the 9th or 10th day after the onset of illness.
In the absence of a vaccine, the only way to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they should take to reduce exposure to the virus, including wearing protective clothing (long sleeves, long trousers); use of approved repellent on the skin and clothing; avoiding areas where ticks are abundant and seasons when they are most active; wearing gloves and other protective clothing while handling animals or their tissues in endemic areas, notably during slaughtering, butchering and culling procedures in slaughterhouses or at home; avoiding close physical contact with CCHF-infected people, and wearing gloves and protective equipment when taking care of ill people.
[The hosts of the CCHF virus include a wide range of wild and domestic animals such as cattle, sheep, and goats. There is no apparent disease in these animals. Animals become infected by the bite of infected ticks and the virus remains in their bloodstream for about one week after infection, allowing the tick-animal-tick cycle to continue when another tick bites.
Although a number of tick genera are capable of becoming infected with CCHF virus, ticks of the genus _Hyalomma_ are the principal vector.
It is difficult to prevent or control CCHF infection in animals and ticks as the tick-animal-tick cycle usually goes unnoticed and the infection in domestic animals is usually not apparent. Furthermore, the tick vectors are numerous and widespread, so tick control with acaricides (chemicals intended to kill ticks) is only a realistic option for well-managed livestock production facilities (<http://www.who.int/news-room/fact-sheets/detail/crimean-congo-haemorrhagic-fever
Ticks are among the factors of many diseases including CCHF, Lyme disease, tick paralysis, brucellosis, plague, salmonellosis, listeriosis, and babesiosis. Activity periods of ticks are seasonal because they need a certain temperature and moisture. Vector ticks movements increase during hot seasons. Ticks, which are the sources of infection, live in the wildlife intertwined with oak forests, close to the mountain slopes or in forests, agricultural land, while others live close to places inhabited by humans and animals. Climate does not affect only the life of ticks, it also affects the multiplicity of host ecology, tick-borne diseases in some regions indirectly, and the causes of the emergence and disappearance in other areas as well (<http://www.academicjournals.org/article/article1380710363_Yigit.pdf
As mentioned in the report above, sporadic cases of CCHF are reported from Iran every year since the disease and its vector are essentially endemic.
"In the absence of a vaccine, the only way to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to the virus.
Public health advice should focus on several aspects:
I. Reducing the risk of tick-to-human transmission:
- wear protective clothing (long sleeves, long trousers);
- wear light coloured clothing to allow easy detection of ticks on the clothes;
- use approved acaricides (chemicals intended to kill ticks) on clothing;
- use approved repellent on the skin and clothing;
- regularly examine clothing and skin for ticks; if found, remove them safely;
- seek to eliminate or control tick infestations on animals or in stables and barns; and
- avoid areas where ticks are abundant and seasons when they are most active.
II. Reducing the risk of animal-to-human transmission:
- wear gloves and other protective clothing while handling animals or their tissues in endemic areas, notably during slaughtering, butchering and culling procedures in slaughterhouses or at home;
- quarantine animals before they enter slaughterhouses or routinely treat animals with pesticides two weeks prior to slaughter. III. Reducing the risk of human-to-human transmission in the community:
- avoid close physical contact with CCHF-infected people;
- wear gloves and protective equipment when taking care of ill people;
- wash hands regularly after caring for or visiting ill people."