epi s6

Introduction to African Swine Fever (ASF)

Case Study Overview

  • Investigation Location: Sardinia

  • Role: OIE (World Organisation for Animal Health) researcher investigators

  • Objective: Gather all possible information from images related to the potential outbreak.

Geographic Context of Italy and Sardinia

  • Studying the implications of the outbreak being located in Sardinia:

    • Island Status: Isolation from mainland

    • Geographic Context: Proximity to other Mediterranean regions including:

    • Monaco

    • Florence

    • Naples

    • Tunisia

    • Geographical Features: Tyrrhenian Sea to the west and Ionian Sea to the east.

Factors Influencing ASF Spread

  • Environmental Factors:

    • Temperature and Humidity: Critical for the survival of the virus.

    • Type of Vectors: Identification of wild boar populations and potential insect vectors like soft ticks.

  • Entry and Exit Points: Analysis of animal movement in and out of the island.

  • Contamination Risks:

    • Infectious Wild Boars: Acting as reservoirs of the virus.

    • Domesticated Animals: Need to consider possible interactions with domestic pigs and other livestock.

    • Contaminated Carcasses or Food Waste: Source of infection for domestic and wild pig populations.

    • Vehicles and Equipment: Potential for virus transmission through contaminated equipment.

Impact of African Swine Fever

  • Economic Consequences:

    • ASF has led to massive losses in pig populations globally, particularly impacting the pork industry.

    • No effective vaccine currently available, leading to animal health crises.

    • Detrimental effects on biodiversity and threats to livestock farming livelihoods.

  • OIE’s Role:

    • Supports countries in preventing and controlling ASF outbreaks through collaboration with partners and experts.

    • Provides mechanisms for outbreak reports and disease alerts worldwide.

Recent Outbreaks and Distribution (2020-2022)

  • Latest geographical distribution maps display outbreaks across various countries.

  • Reports of recent ASF virus containment efforts in:

    • Russia

    • Zambia

  • Notifications: Highlighted in figures tracking distribution and relationship among infective strains and affected regions.

Environmental and Climatic Considerations for ASF

  • Mediterranean Climate:

    • High humidity and temperatures contribute to vector populations.

    • Areas with low tick populations are critical for reducing ASF risk.

  • Impact of Geography:

    • Rural settings increase contact opportunities between livestock and wild species.

  • Biosecurity Challenges: Lack of proper facilities and sanitation can lead to higher transmission rates of ASF.

Clinical Signs of ASF

  • Symptoms in Affected Animals:

    • Lethargy

    • Fever

    • Anorexia (loss of appetite)

    • Respiratory disorders

    • Nerve disorders

    • Possible epistaxis (nosebleed)

    • Death

  • Postmortem Examination Findings:

    • Enlargement and discoloration of the spleen (splenomegaly)

    • Accumulation of blood in body cavities

    • Signs of hemorrhagic diarrhea, and other severe lesions.

Investigation Protocol for Outbreak

  1. First Steps:

    • Report the suspicion to OIE.

    • Implement immobilization of animals in the affected area.

  2. Engage with Farm Owners for Anamnesis:

    • Inquiry into the presence of wild boars and recent animal introduction.

    • Understand spatial and temporal clustering of cases.

    • Detection of asymptomatic carriers leading to horizontal and vertical transmission risks.

  3. Mapping of Cases:

    • Analyze data of cases by month, which reveals environmental aspects linked to the spread.

Future Recommendations for ASF Control

  • Strengthen biosecurity measures on farms to mitigate animal movement risks.

  • Address challenges regarding unregistered movement and illegal possession of animals.

  • Improve tracking and reporting of animal health data longitudinally.

Conclusion

  • Continuous monitoring of ASF prevalence necessary for informing future health control measures.

  • Development of educational programs on biosecurity practices to minimize outbreaks in agricultural communities.