Congo Fever: Precautions to Take
Crimean–Congo haemorrhagic fever (CCHF) is a zoonotic disease caused by Nairovirus of the family Bunyaviridae. Crimean-Congo haemorrhagic fever virus (CCHFV) contains RNA as its genetic material and it is transmitted from one animal to the other or human beings through the bite of infected Hyalomma ticks mainly. The virus remains within the blood of cattle, buffalo, sheep or goat without causing any clinical disease. However, if the infected tick(s) bite any human host, the disease is likely to occur. On the occasion of Eid ul Azha, chances of occurrence of the disease are many folds increased as the interaction of general public is high during this event. According to the Center for Disease Control (CDC), main clinical signs of disease in humans include high grade fever, muscle pain, dizziness, neck pain and stiffness, backache, headache, sore eyes and sensitivity to light. Nausea, vomiting, diarrhea, abdominal pain and sore throat may also be present. Other clinical signs include tachycardia (fast heart rate), lymphadenopathy (enlarged lymph nodes), and a petechial rash (a rash caused by bleeding into the skin) on internal mucosal surfaces, such as in the mouth and throat, and on the skin. The individuals facing any of the signs should visit the physician in emergency.
Prophylaxis / Prevention:
The disease is highly infectious but it can easily be prevented. Following are the recommendations that should be practiced throughout the year particularly by the individuals having close and frequent contact with food animals.
- Wear gloves while touching the animals.
- Light color clothing should be worn so that ticks can easily be visualized, if any.
- Wear full-sleeves shirts and joggers / laces’ shoes with socks while visiting animal markets.
- Don’t crush any tick with your hands / finger.
- Avoid contact with the blood and body fluids of livestock. After slaughtering, blood should preferably be buried under the ground.
- Rotational grazing after an interval of 4 months can also reduce the tick population significantly.
- Some of the developmental stages of ticks adhere to the vegetation and attach to the near-by passing cattle. So the vegetation should be cleared. However, this method has deleterious effects ecosystem and soil productivity.
- Cattle and buffalo should be housed in different sheds. Cattle are more susceptible to be infested with ticks as compared to buffaloes. Intermingled raising of cattle and buffalo may cause heavy tick infestation in stressful environment.
- Slow burning of the wastes for 2-3 days near the walls of the animal sheds is beneficial to decrease the tick load on the animals as the female ticks lay eggs in cracks and crevices. The smoke of burning waste material kills the ticks.
- The walls of the animal sheds should be cemented or “teep” so that cracks and crevices may not provide sites for breeding of ticks.
- Quarantine strategies for newly purchased animals must be in place. If the purchased animal(s) bear ticks, such animal(s) should not be mixed with the herd until and unless it is free from ticks.
- Regular and prescribed use of acaricides: The drugs that are used to kill the ticks are called acaricides. Dipping, washes, spraying, pour-on, spot-on or injections of acaricides are the ways to getting rid of ticks.
- One mL of EcofleeceTM or CyprinTM20 EC can be added to 1L of water and sprayed on the body of the animal.
- Delta – 25TM solution contains 2.5% deltamethrin. 2mL of this drug is diluted in 1 L of water and sprayed on the body of the animal. The recommended dose of this acaricidal drug is 1:1000 (i.e., 1 mL for 1L of water) for filling and replenishment of the dipping tank.
- Neguvon contains trichlorfon and can be used externally for killing ticks at concentration of 0.15% through dipping or spraying.
- Ivermectin can be given subcutaneously at dose rate of 200 μg/kg (i.e., 1mL/50 kg)
- In addition, animal sheds should be sprayed with insecticide (usually twice the strength used for dipping or spraying e.g., EcofleeceTM @ 1:500) besides dipping or spraying the animals with acaricides. This article is jointly authored by Dr. Mughees Aizaz Alvi1, Dr. Muhammad Haleem Tayyab, Dr. Imaad Rashid1, Dr. Khurram Ashfaq1 ,1Lecturer, Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad.