Also referred to as warthog fever, the African Swine Fever (ASF) is a highly contagious viral disease that affects domestic pigs and wild boars.
This disease was first identified in Kenya in 1910, severely affecting the warthogs and the forest pigs.
Later on, after 1957, this disease dispersed its tentacles all over the countries of Asia and Europe.
The primary reason behind this disease’s dispersal was the processed pork products used in countries like Italy, Portugal, Brazil, Spain, etc.
This fatal disease of swine could be substantiated by various symptoms like leukopenia, elevated pulse, high fever, lesions, or even death of the swine within four to seven days of the fever.
The only relief that comes with the African swine fever is that it cannot affect humans or other animals and livestock.
However, humans can unknowingly carry the virus that causes this disease and hence can incentivize the dispersal of the disease.
So if you want to learn about African swine fever, this is the right article you come across.
African Swine Fever Virus (ASF Virus)
The virus that may be responsible for the African swine fever belongs to the family asfarviridae and is classified as an astrovirus.
This virus could be detrimental[1] to the health of the pigs because it can survive partial cooking, smoking, good heat, and dryness and could even live up to six to 9 months in the chilled carcasses.
However, the incubation period of this virus may range anywhere from 5 to 15 days.
But it is altogether different from the togavirus in its physical, chemical as well as antigenic components which causes hog cholera.
Due to the same reason, it still might be difficult to distinguish African swine fever from acute classical hog cholera.
Both these diseases might result in a high fever that could last for approximately four or five days.
However, the point of difference here is that once the fever subsides, the African swine fever virus could result in the death of the swine within two days as compared to seven days for hog cholera.
Moreover, another significant point of distinction here could be that immunization might help in the prevention of hog cholera.
However, it may not be effective in the prevention of African swine fever because there is no vaccine available for this virus, as per this study[2].
Transmission Of Various Form Of The ASF Virus
According to research[3], the transmission of the natural African swine fever virus could be studied from the different disease manifestations like the peracute, acute, subacute, and chronic forms of this disease.
When the disease is in its peracute form, the pigs can die within four Days Post Infection (DPI) without having any gross lesions.
On the other hand, the acute form of the disease led to a higher percentage of mortality in the infected pigs, which was 90- 100%.
Moreover, the death of the pigs in this category was seen after 4 to 21 Days Post Infection.
Certain significant pathological changes were even sighted in these pigs like-
- Pulmonary Edema
- Petechial hemorrhages in the urinary bladder, kidneys, and lungs
- Skin erythema
- Hemorrhagic lymphadenitis
- Hyperaemic splenomegaly
Now coming at the subacute form of the disease, which might be caused due to moderately virulent isolates, the mortality percentage here was 30 to 70%.
The incubation period in this form of the virus was even greater, and the pigs had died approximately 20 days post-infection (DPI).
The clinical signs were even less marked in this African swine flu virus category.
However, some of the symptoms like hemorrhage, edema, and vascular changes, were more severe as compared to the acute form.
The low virulence isolates could result in chronic forms of this disease, which may be seen by low mortality rates, delayed growth, skin ulcers, joint swelling, and emaciation.
The African swine fever can be transmitted through various methods[4] like direct contact with the infected pig, their body fluids, or feces.
Other than direct contact, indirect contact through equipment, vehicle or the people who work with the pigs on the pigs’ farms can even incentivize the dispersal of this disease.
Another method of dispersal is the infected pig meat or other meat products that are eaten by the pigs.
Symptoms Of African Swine Fever
One of the most common signs and symptoms of African swine fever is the high mortality rate in pigs, irrespective of age.
Though the most credible way of detecting[5] African swine fever is to check for the virus through laboratory testing, you could even know about it through different signs and symptoms.
These symptoms could include-
- Sudden loss of appetite
- Abortion
- High fever
- High death loss
- Coughing
- Depression
- Hemorrhages on the skin as well as the internal organs like the lymph nodes
- Diarrhea
- Vomiting
- Difficulty in breathing
If you observe any of these symptoms in your pig, then it could be crucial to connect to your vet as soon as possible.
The vet can help provide the correct treatment and quarantine for your pigs so that you can reduce the damage done to the farm.
Treatment For African Swine Fever
Presently, there is no particular[2] form of treatment or vaccination that could help to cure African swine fever.
However, there are certain precautionary measures that you could take to protect the health of your pigs.
One of the best methods to reduce the severity of the dispersal of this disease could be to isolate the infected animals.
This is because the contact between the healthy and the sick pigs can lead to the dispersal of the African swine fever.
Other than this, here are other tips that could help you to prevent African swine fever from entering your farm.
Preventing African Swine Fever
There are certain methods[6] that the pork producers could follow to protect their pig herds from African swine fever and hence continue the business of the pork industry.
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Following Strict Importation Measures
If you want to evade the entry of African swine fever into your farm, then you should implement strict importation measures for both the infected live pigs as well as pork products.
Make sure the countries that have ASF-positive pork products do not export their animals to your farm.
You could even check the infected regions before importing pork products that might be potentially contaminated.
-
Efficacious Disposal Of Garbage
It is very crucial for you to effectively dispose of the garbage and then clean the place thoroughly because if the food waste is contaminated with ASF, then it could infect the other pigs as well.
Make sure not to dispose of the garbage at a place where the wild swine species could get access to them.
-
Intensify Your On-Farm Biosecurity Practices
As a producer, if you want to evade the entry of the African swine fever on your farm, then you may aim at enhancing[7] your on-farm biosecurity practices.
For this, you could work with your veterinarian and make sure to limit the entry of foreign visitors to your farms.
The major reason behind this is that the African swine fever virus can easily travel on the clothing and shoes of humans and hence, could affect a good herd of pigs.
-
Aim At Rapid Slaughtering Of All The Pigs
If you observe any of the signs and symptoms of African swine fever in some of your pigs then it would be recommended to slaughter all the pigs whether they are infected or not.
This could help you to avoid the dispersal of the disease to the other healthy pigs. Hence, this might be a short-term method that may help you to eradicate[8] this disease.
-
Restricted Animal And Human Movements
You may always be careful related to the movements inside your pig farms, since people, equipment and vehicles can even be the carrier of the African swine fever.
You may evade their entry into your farm. Moreover, also make sure that the people who enter your farm have not been in contact with other pigs in the past 48 hours.
Other than this, if any equipment and vehicles are entering the farm then you may clean and disinfect them before their entry.
The carcass hauling trucks are also at a higher risk are to spreading African swine fever because of the secretions and excretions from the dead animals in it.
-
Early Detection Of The Virus
As soon as you observe any signs and symptoms of the virus, you should immediately contact your vet and get early detection of the virus through laboratory tests.
The Bottom Line
Thus, this was all you need to know about African swine fever. Though African swine fever does not affect humans, it could be detrimental to the health of the pigs.
Moreover, since there is no proper treatment for this disease, you may always make sure to be careful and take care of your pigs if you have a pig farm.
If you keep pigs, then it is your responsibility to prevent further disease outbreaks. Other than this, you should immediately contact your vet in case you observe any symptoms in your pigs.
And if you didn’t know, then frozen meat from the infected pigs can even have the ASF virus in them for up to six months.
So, it is not just the visitors you need to pay heed to rather, the diet of your pigs is crucial as well.
References/Sources
Working4Health prefers using primary and verified references. We have strict sourcing guidelines and our primary references include peer-reviewed research, academic, and medical institution studies.
- African Swine Fever (ASF) Last Modified: Aug 31, 2022 Available from: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/swine-disease-information/african-swine-fever/seminar
- Natasha N. Gaudreault and Juergen A. Richt Subunit Vaccine Approaches for African Swine Fever Virus Vaccines (Basel). 2019 Jun; 7(2): 56.Published online 2019 Jun 25. doi: 10.3390/vaccines7020056
- J C Gómez-Villamandos, M J Bautista, P J Sánchez-Cordón, et al. Pathology of African swine fever: the role of monocyte-macrophage Virus Res. 2013 Apr;173(1):140-9. doi: 10.1016/j.virusres.2013.01.017. Epub 2013 Jan 29. Available from: https://pubmed.ncbi.nlm.nih.gov/23376310/
- African Swine Fever Available from: https://www.daera-ni.gov.uk/articles/african-swine-fever
- Inmaculada Galindo and Covadonga Alonso African Swine Fever Virus: A Review Viruses. 2017 May; 9(5): 103.Published online 2017 May 10. doi: 10.3390/v9050103
- Yong-Joo Kim, Bongkyun Park, Hae-Eun Kang Control measures to African swine fever outbreak: active response in South Korea, preparation for the future, and cooperation J Vet Sci. 2021 Jan; 22(1): e13.Published online 2021 Jan 22. doi: 10.4142/jvs.2021.22.e13
- Florence Mutua and Michel Dione The Context of Application of Biosecurity for Control of African Swine Fever in Smallholder Pig Systems: Current Gaps and Recommendations Front Vet Sci. 2021; 8: 689811.Published online 2021 Aug 2. doi: 10.3389/fvets.2021.689811
- Cristina Jurado, Marta Martínez-Avilés, Ana De La Torre, et al. Relevant Measures to Prevent the Spread of African Swine Fever in the European Union Domestic Pig Sector Front Vet Sci. 2018; 5: 77.Published online 2018 Apr 16. doi: 10.3389/fvets.2018.00077
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Otella has an experience of around eight years of writing about health and nutrition-related topics. She is a full-time mother and a housewife, and the time she has left after doing her mother and household duties is spent writing for Working for Health as a full-time writer. Her life goal is to raise both her boys into a gentleman, and at the same time, she wants to educate people on how to keep themselves fit by tweaking their daily diet.