Summer is the most dangerous time for the rapid spread of African swine fever (ASF), so domestic pig farmers need to be extra vigilant during this period. The rapid spread of ASF is due to the active movement of wild boar as they search for food. Piglets are particularly active, moving quickly to explore new areas in search of food.
In the first half of the year, the highest number of cases among wild boar was detected in the Ventspils district, where 36 wild boar were found to be infected in the first six months. This is followed by the Alūksne district with 34 infected wild boar, the Madona district with 29, and the Gulbene district with 28. Notably, this year saw the first outbreaks of ASF in domestic pigs in the Gulbene and Madona districts, in Stradi parish and Cesvaine parish respectively. The latest case was recorded this week in Robežnieki parish, Krāslava district. In total, there have been four outbreaks of ASF in domestic pig farms this year.
A relatively high number of ASF-infected wild boar were also recorded in the first half of the year in the Rēzekne district (19), the Tukums district (16), and the Valmiera and Cēsis districts (13 in each).
A moderately high level of ASF infection among wild boar was found in the Jēkabpils (8), Dobele (7), Kuldīga (7), Sigulda (7), Balvi (5), South Kurzeme (5), Krāslava (5) and Preiļi (5) districts. Conversely, a relatively lower prevalence of ASF was observed among wild boar in the Ludza (4), Smiltene (4), Augšdaugava (3), Limbaži (2), Līvāni (1), Ogre (1) and Varakļāni (1) districts.
When assessing the number of ASF cases at the parish level, the highest number of infected wild boar in the first half of the year was found in Stāmeriena and Ziras parishes, with 13 infected wild boar in each. Slightly fewer – 11 cases – were found this year in Dzelzava and Lendži parishes. Meanwhile, 10 ASF-infected wild boar were found in both Straupe and Kocēni parishes. Fewer than 10 cases were recorded in the first six months in Užava, Jaunanna, Indrāni, Slampe and Jūrkalne parishes.
The Food and Veterinary Service (PVD) urges domestic pig keepers to be especially cautious and to strictly observe biosecurity requirements. If pigs appear unwell – for example, if they have lost their appetite, spend most of their time lying down, or if there is a suspicion of a high body temperature – a veterinarian or the PVD must be notified immediately.
Kristīne Lamberga, Director of the PVD Veterinary Surveillance Department: “Since early spring, we have been warning about a second wave of African swine fever, which has now, unfortunately, become a reality. The greatest threat to domestic pig farms is wild boar, which are known for their rapid population recovery. The ASF virus is extremely resilient in the wild. This facilitates the spread of infection to new herds of wild boar, which become a reservoir for the virus in nature. Infected wild boar are a constant threat to domestic pigs, which is why the PVD urges pig farmers to follow biosecurity measures at their farms strictly and even meticulously. Our experience shows that it is precisely these apparent trifles that provide the widest gateway for the virus to enter a farm.”
Aivars Bērziņš, leading researcher at the Institute of Food Safety, Animal Health and Environment “BIOR”, points out that ASF is an extremely dangerous infectious disease. Unlike classical swine fever, antibodies do not create immunity in animals or protect them from re-infection, which is why the virus is extremely hardy. Although the virus is harmless to humans, it causes significant socio-economic losses. “BIOR researchers represent Latvia in an EU-funded ASF vaccine development programme. The tests and trials conducted so far have shown good results, which suggests that in the very near future, a vaccine could be created, which will become a solution for combating ASF both in Europe and in other countries affected by the fever,” says A. Bērziņš.
Valters Lūsis, Head of the Hunting Department of the State Forest Service: “According to State Forest Service data, the number of wild boar in recent years has averaged 26,000 animals. The wild boar is a non-quota game animal that can be hunted all year round. Hunting is a very important factor in both controlling the wild boar population and reducing the spread of ASF. By reducing the density of the wild boar population, it is also possible to weaken the spread of ASF. Hunters need to be aware that driven hunts cause more intense movement of wild boar and can therefore also affect the spread of ASF. Therefore, during periods of heightened ASF prevalence, and in places where ASF has already been detected, the intensity of driven hunts should be reduced for a time, and the focus should be placed on waiting-stand hunts for wild boar. This is necessary to avoid unnecessarily provoking the movement of infected wild boar and the infection of healthy ones.”
The European Food Safety Authority (EFSA) highlights that over the last decade, African swine fever has severely impacted the European pig farming sector and the regional economy as a whole. The situation in Europe remains risky, which is why farmers, hunters and veterinarians play a crucial role in reporting suspicious cases. To help combat the spread of ASF, the EFSA has created a webpage with information materials on ASF and how to fight the spread of this infection.
About African swine fever
African swine fever is a deadly viral disease that affects domestic pigs and wild boar. The virus is harmless to humans, but it causes significant socio-economic challenges in many countries. There are currently no approved vaccines against ASF in Europe, so in the event of an outbreak, it may be necessary to cull a large number of farmed pigs in the affected area. The ASF virus is extremely resilient, and unlike classical swine fever, antibodies do not create immunity in animals or protect them from re-infection. Therefore, the process of developing an ASF vaccine is slow and complex.