African Swine Fever roadmap:
Control Strategies
Roadmap for the development of control strategies for ASF
Download ASF Control Strategy RoadmapB
Latent/carrier
Latent/carrier
Research Question
- The mechanisms of virus (or experimental vaccine) persistence is unknown
Research Gaps and Challenges
- Establish how viruses result in persistent infection
- Improve knowledge of the role of the survivor pigs as potential shedders by the use of appropriated diagnostic serological and virological tests for identification/detection of
these animals - Investigate the mechanisms involved in the protective immune response responsible for the appearance of carrier animals
Solution Routes
- Perform studies on natural survivors
State Of the Art
- Long-term persistence following infection of pigs with genotype I isolates of reduced virulence has been demonstrated. These persistent infections have been demonstrated to be transmissible from pigs persistently infected with the low virulence genotype I NH/P68 isolate to contact pigs. Low virulence isolates can cause chronic forms of the disease. Pigs that survive infection have been shown to carry virus in tissues or blood for long periods of time, which may contribute to virus transmission, disease persistence, sporadic outbreaks and sudden reactivation of the disease. There is limited experimental evidence for transmission from persistently infected to naïve animals, and the relevance of persistently infected animals as carriers of ASF in the field is not clear, but data on healthy infected animals keeps accumulating, suggesting that the virulent virus could survive for long periods of time in the recovered pigs and a recrudescence of virulence may occur at later times. Recent data using a moderately virulent isolate of different genotype during a shorter period
of time, do not support the establishment of a carrier status in animals surviving infection, though long term detection of viral genome in blood (for at least 90 pi) is consistent with many other reports. Persistent
infection with ASFV is reported to occur in warthogs and in domestic pigs surviving acute viral infection
Projects
What activities are planned or underway?
Africa's Long Depression: The Growth and Debt Crises of 1975-2000
Planned Completion date 01/03/2027
Participating Country(s):
United Kingdom
Unlocking potential: developing innovative adolescent screening visits for health promotion, prevention and treatment in low-resource settings
Planned Completion date 01/01/2028
Participating Country(s):
United Kingdom