Insects and People: Arthropods and North Carolina Diseases

Technical Terms

  • Disease: negative response of the host to the agent (an illness)
  • Agent: pathogen responsible for infection (virus, bacterium, etc.)
  • Vector: the organism (insect, mite, tick) that transmitted the agent from an infected host to a non-infected host
    • These come in the form of mosquitoes, ticks, bugs, lice, or other biting flies
    • Can also come in the form of a fomite
  • Reservoir: host animal(s) that harbors the agent for long periods of time, often with no symptoms of the disease
    • A host (typically an animal) that holds the pathogen in nature until it is bitten by a vector host
    • The vector will then bite a human transmitting the pathogen

How Diseases Are Transmitted

  • Mechanical Transmission: disease agent piggy-backs on the vector
    • Filthy flies and roaches; dysentery
  • Biological Transmission: some part of disease agentā€™s life cycle in a vector
    • Injected during blood meal or frass rubbed into bite

Disease Close to Home

  • Lyme Disease: discovered in USA in 1975
    • Agent: spiral-shaped bacteria
    • Reservoir: wild animals (white-footed mice and white-tailed deer)
    • Vector: black-legged tick or deer tick
    • Target: humans and dogs (possibly horses and cows)
    • Location: Coastal Plain, some Piedmont (woods, pastures, brush)
    • Potential: lower in South because ticks donā€™t bite humans as often
    • Symptoms: bullā€™s-eye rash on 50-80% of people within 30 days, fatigue, headache, stiff neck, muscle ache, fever, chills,
    • if untreated, 10-15% of people may get encephalitis, heart irregularities, meningitis, multiple sclerosis, arthritis
  • Rocky Mountain Spotted Fever (Tick Typhus)
    • Agent: bacteria-like microbe called rickettsia
    • Reservoir: wild and domestic animals (various sizes)
    • Vector: American dog tick
    • Target: humans and dogs
    • Location: mostly Piedmont (woods, pastures, brush)
    • Potential: NC highest # of cases, but the smallest # of ticks infected
    • Mechanism: tick must be attached at least 6 hours
    • Symptoms: measles-like rash around wrists and ankles within a week, fever, chills, headache, muscle ache within 2 weeks
  • Ehrlichioses: new to NC
    • Agent: bacteria
    • Reservoir: probably white-tailed deer
    • Vector: probably lone star tick
    • Target: humans
    • Symptoms: fever, headache, muscle ache, nausea, but no rash
  • Prevention and treatment
    • Tuck in clothes, use repellent, examine clothes/body/pets
    • Antibiotics very effective

Red Meat Allergy

  • Also called Galactose-alpha-1, 3-galactose (Alpha gal for short)
    • An allergy to mammal meat except for old-world monkeys and apes
  • This allergy develops after being bitten by a Lonestar tick that recently fed on a non-ape animal
  • The allergy can be as severe as swelling digestive track and anaphylaxis
  • We have these ticks in abundance hereā€¦ Do your tick checks!