He was alarmed by a new virus seen in Turkey and the disease it caused. Animal markets were closed due to the foot and mouth virus seen in 3 different cities in the country. The Ministry of Agriculture and Forestry has canceled the permits of veterinarians, veterinary health technicians and technicians throughout Turkey until further notice. Ministry of Agriculture and Forestry “As a result of the studies carried out, the first case with SAT-2 serotype foot and mouth disease was detected.” made the statement. After this statement, what is the foot and mouth virus seen in animals and what are the symptoms took its place as the most important topic on the agenda. So, what is foot and mouth disease, how does it spread and what are the symptoms?
Foot-and-mouth disease is a viral disease of even hoofed animals. It is popularly known as a plate or a dabak. It is a viral disease that can be seen in all cloven-hoofed animals, domestic or wild, and causes death in weak and young animals in chronic conditions, and generally causes loss of meat, milk and workforce. It is among the diseases that must be reported by the Ministry of Agriculture and Forestry of Turkey. Although the mortality of the disease is low, it has high morbidity. This means: Although not lethal, it spreads rapidly in the herd or in the area. Although it is considered a zoonosis, transmission to humans is extremely rare.
Foot and mouth disease is an acute, highly contagious and zoonotic viral infection of ungulates. The transmission rate of the disease is high and can reach up to 100% in sensitive animal populations. For this reason, the disease is of great importance in economic, political and commercial aspects.
The causative agent of the disease is the foot and mouth virus, which is in the Aphtovirus subgroup of the Picornaviridae family. There are seven antigenically different serotypes of the virus, namely O , A, C , SAT-1, SAT-2, SAT-3 and ASIA 1. (O) serotype has II, A serotype has 32, C serotype has 5, SAT I serotype has I, SAT 2 serotype has 3, SAT 3 serotype has 4, and ASIA I serotype has I subtype. The absence of cross immunity between serotypes makes it difficult to fight the disease.
The virus shows different susceptibility to physical agents. It is heat resistant and becomes ineffective by being destroyed in 37 hours at 12oC, in 60/65 hour at 1-2oC, and in a few minutes at 85oC. However, it is highly resistant to low temperatures and sudden freezing and thawing.
When did foot-and-mouth disease first appear?
The disease was first described in 1546 by Hieranymus Fracastorius. In Turkey, it was first recorded as statistical information in 1914.
It is in the Aphtovirus subgroup within the Picorna group of viruses. In addition to 1 serotypes of the virus with known (A, O, C, Sat 2, Sat 3, Sat 1 and Asia 7) names, there are approximately 64 different subtypes.
The most common serotypes in Turkey are A, O and Asia-1 serotypes.
- High temperature, direct sunlight are unsuitable conditions for the virus.
- Direct sunlight causes the virus to be destroyed. In conditions not exposed to direct sunlight
- 40 °C in 12 hours,
- 60-65 °C in 30 minutes,
- If it is 85°C, it will be destroyed immediately. (boiling the milk, cooking the meat according to the base removes the virus)
- The virus survives in normal weather conditions (eg room conditions),
- The virus is resistant to many known disinfectants.
- Disinfectants to which the virus is unstable are as follows.
- Potassium hydroxide (KOH)
- 4% soda, acids (vinegar)
- 1-2% NaOH (sodium lye)
Standards of living under normal conditions of the disease agent
- Frozen semen (-270 °C) 30 days
- 24 days in fleece
- 28 days on skin and hair
- 130 days for hay and grains
- shoes and rubber boots 80-100 days
- 28 days in soil
- It preserves its ability to cause disease in frozen fresh meat for 1 year.
How is foot and mouth disease spread?
The spread of the disease occurs through 2 different elements:
- 1- Sick animals
- Their mouth drooling
- Urine and feces
- milk
- With the eruption of vesicles formed in the outbreaks
- 2- Carrier animals and resources
- Mice, Birds, Boar, Poultry play a role in the spread of the disease.
- Artificial insemination (with diseased sperm or material)
- Forage, litter, water,
- Using the clothes, clothes and materials (milking machine, spoon, chain) used in the diseased environment without disinfection,
- Animal transports (with diseased animals, materials or non-disinfected transport vehicles),
- Putting diseased animal products on the market without undergoing the necessary treatment plays an important role in the disease becoming epidemic.
Incubation period of foot and mouth disease
After finishing the active incubation period (min. 2-7 days in cattle, 1-6 days in sheep);
- High fever (40-41 °C)
- sluggishness, loss of appetite,
- Loss of milk yield,
- Don't lag behind the herd.
- The agent forms the first lesions called primary aphthae in the area where it is taken into the body. Later, it settles in the stratum spinosum cells of the stratified epithelium and reproduces here. Hydropic degeneration begins in the cells it reproduces, and over time, the cells die and fluid-filled vesicles begin to form. Since the stratum basale layer is intact, bleeding is not seen in the lesions. Lesions are frequently seen in tongue, oral cavity mucosa, gingiva (gum), buccal mucosa, internail and breast tissue. These vesicles burst due to tongue movements and various reasons.
- Redness in the inner mouth area, not eating, drooling from the mouth, drooling from the mouth, peeling of the tongue, tongue protrusion are seen. Sometimes, the nearby vesicles merge and become bulla and become larger.
- Vesicles formed in the mouth area can also be seen in the area between the feet and nails. Consequently,
- Wounds between the nails, redness, abscess and nail fall can be seen in the following periods.
- Due to breast inflammations;
- The animal does not even allow the calf to suckle,
- Takes pain,
- Refuses my right
- Milk yield decreases.
- Mastitis can be seen in the following periods.
- Sudden death can occur in calves, lambs and kids before the symptoms of the disease are fully seen. The reason for this is that the agent directly settles in myocardial cells and causes peracute/acute myocarditis. As a result of necropsy, the heart muscle has the appearance of tiger skin. This is mostly caused by the O strain of the virus.
The disease can also be seen locally and mildly in humans. Its symptom is the formation of water-filled blisters in the mouth and hand area. It is more effective in children.
Foot and mouth disease symptoms
Fever, loss of appetite, depression and decrease in milk yield are the first clinical findings in cattle. Within 24 hours, saliva flow begins and vesicles form on the tongue-gingiva. Vesicles can be encountered in the interdigital region, coronary region, breast skin, oral and nasal mucosa. Large ulcerative sores may form with rupture of the vesicles.
Although the wounds (lesions) on the tongue usually heal in a few days, the lesions on the feet and in the nasal region are mostly exposed to secondary (secondary) bacterial infections. As a result of secondary bacterial infections, pneumonia and mastitis may occur, and nails may fall.
The disease has a milder course in sheep and goats. The disease is usually characterized by lameness in sheep, and lameness persists. Lesions in the mouth are smaller and shorter in duration than lesions in cattle. Generally, the economic losses caused by the disease are lower than those of cattle, and clinical manifestations are determined only by careful observation.
Although the death (mortality) rate of foot and mouth disease is low, myocarditis cases resulting in death can be seen in young animals as a result of localization of the virus in the heart. The transmission (morbidity) rate of the disease is high, and the economic losses due to the rapid decline in meat and milk yields are important.
Although clinical findings suggest the disease, the definitive diagnosis is made using virological or serological methods. In differential diagnosis; lameness, mucosal erosions, drooling, nasal discharge and infections causing breast lesions should be considered.
How is foot-and-mouth disease diagnosed?
Saliva in the mouth area, foamy discharge and/or erosions in the internail area are the most obvious images for preliminary diagnosis. These lesions can be seen in the breast region, especially on the nipples, but this does not provide a complete differentiation for diagnosis.
Treatment of foot and mouth disease
It is a viral disease, there is no cure because there are many types. Veterinarians apply different treatment methods according to the course of the disease.
Prevention measures against foot and mouth disease
Foot and mouth disease is a disease included in the epidemic disease control program of the Turkish Ministry of Agriculture and Forestry. Therefore, a vaccination program is carried out every 6 months throughout the country.
- Whenever possible, barns should not be entered without disinfection.
- The walls, floors and mangers of the barns should be constructed of easily disinfectable materials and disinfection should be done regularly.
- Next to the barns where the animals are permanently attached, a separate section should be built where the newly purchased animals will be tied.
- Caregivers should be provided to wear special clothes and boots when entering the barn, and others should not be allowed to enter the barn.
- Disinfectant mats on which caregivers or animals will step when entering and exiting the barn must be in front of the doors.
- Before milking, disinfection of hands, udders and milking equipment should be meticulously taken care of.
- Animals should be systematically vaccinated against foot and mouth disease.
- Newly brought animals to the region should be monitored whether they carry the disease.
- Unvaccinated animals should not be brought into the barn.
- Suspicious animals should be taken to a separate barn immediately.
- The caregiver who takes care of the sick animal should not enter other barns, the clothes and boots he wears should stay in that barn.
- Leftover feed and litter removed from the barn with the sick animal should be burned immediately.
- It is a notifiable disease. If it is seen, it is necessary to inform the Ministry of Agriculture.