African Swine Fever (ASF) is one of the most severe and devastating viral diseases affecting pigs globally.
Recently, ASF is affecting many pig farms globally. This viral disease, which affects pigs of all ages, has no cure or vaccine, making it a major concern for both the veterinary community and pig farmers across the globe.
It cannot be transmitted to people, and properly prepared pork products are safe to eat. Although it is not a direct threat to human health, its deadly nature in swine could result in pork product shortage. Due to its high mortality rate, ASF presents a serious threat to the global pig industry.
What Is African Swine Fever?
African Swine Fever is caused by a double-stranded DNA virus that is incredibly robust and complex. The virus is more resilient than many other swine diseases, including Porcine Epidemic Diarrhea (PED). It is stable over a wide range of temperatures and pH levels, which contributes to its persistence in the environment.
ASF can survive various processes such as putrefaction, meat maturation, cooking, smoking, curing, air drying, salting, and freezing.
The virus can remain infectious for extended periods under certain conditions:
- 11 days in feces
- Months in bone marrow
- 15 weeks in chilled meat
- More than 15 weeks in frozen meat
- 3-6 months in cured hams that haven’t undergone high-temperature cooking
How Is ASF Transmitted?
ASF spreads primarily through oral and nasal exposure to the virus. It can be transmitted through direct contact, such as infected pigs coming into contact with healthy pigs.
Indirect transmission can occur when pigs are exposed to contaminated environments, including contaminated excretions, secretions, tissues, or meat products.
In addition to direct and indirect contact, certain types of ticks and flies can act as vectors, helping to spread the virus. This versatility in transmission methods makes ASF difficult to control and contains the potential for rapid outbreaks if strict biosecurity measures are not followed.
Symptoms of ASF
The symptoms of African Swine Fever can vary in different kinds of pigs. But the sign that remains similar to each kind is that the disease generally progresses quickly, with high mortality rates. Early symptoms may include:
- High fever in infected pigs
- Vomiting and diarrhea
- Weakness and difficulty standing
- Coughing or labored breathing
- Red or blue blotches on the skin, particularly around the ears and snout
In sows, the disease can lead to reproductive issues, including miscarriage, abortions, stillbirths, and weak litters. ASF often progresses rapidly, and within 10 days, a significant portion of infected animals will die.
The incubation period of ASF ranges from 5 to 15 days, with both acute and chronic forms of the disease. The acute form is characterized by hemorrhagic fever and multiple organ involvement, while chronic cases may have milder symptoms but can still lead to significant production losses.
If a pig survives the infection, it can continue shedding the virus for up to 6 months, posing a continued risk of transmission.
How ASF is diagnosed?
The core reason that has added to its spread on a large scale, is that the symptoms of African Swine Fever are very similar to other swine diseases.
If any of the symptoms is appeared in pigs, it is must to go for a clinical treatment as soon as possible.
Early detection and accurate diagnosis are vital for controlling and preventing the outbreak of this virus to healthy pigs. Laboratory tests are often required to definitively confirm the presence of ASF, as clinical signs alone may not be sufficient to make an accurate diagnosis.
Preventing and Controlling ASF
Currently, there is no cure or vaccine available for ASF, which makes prevention and control efforts crucial.
However, biosecurity measures are essential in preventing the introduction and spread of the virus. These measures and precautions may include:
- Strict quarantine procedures for new pigs entering a farm
- Regular cleaning and disinfecting of facilities
- Monitoring pigs closely for signs of illness and isolating affected animals immediately
- Ensuring that feed, equipment, and vehicles are free from contamination
