Medical Entomology

• What is the most common insect vector?

  Mosquitoes
• Envenomation?

  Venoms cause pain

  Are hemolytic and are hemorrhagic (increase bloodflow)
• Allergic reactions to envenomation?

  Anaphylactic shock, potential deadly swelling of the airways and other tissue (2-5%)
• Hymenoptera: Aculeata?

  Ovipositor is used to sting

  Apamin is produced to inhibit calcium-activated K+ channels
• Biting insects?

  Most mandibular insects can not break skin
• Biting insects?

  Most biters are hematophagous or fluid feeders
• Ectoparasites?

  Fleas, lice, bedbugs, conenose bugs, louse flies
• Flying Ectoparasites?

  Pierce - Skeeters

  Pooling - Flies

  Eyes - gnats and moths
• Calyptra moths?

  Blood drinking moths with a modified proboscis

  
• Insects as vectors?

  Biting insects are vectors for the infective stages of diseases

  
• Mechanical Transmission?

  Vectors that adhere to the feet or mouthparts to move to a new host
• Biological Transmission?

  Occur within the host's body then spread to another host
• Disease Transmission: Persistant?

  Does not need reacquisition of a pathogen from infective hosts to continue to transmit the disease
• Disease Transmission: Circulative?

  Pathogen goes from the gut to the hemocel, then is transmitted through the saliva
• Disease Transmission: Propagative?

  Pathogen that increases in a vector
• Disease Transmission: Cyclodevelopmental?

  Pathogen develops but does not increase in number in the vector
• Disease Transmission: Cyclopropagative?

  Develops and increases in numbers in the host
• Malaria?

  Active plasmodium destroy blood cells in large quantities

  Transmitted by Anopheles
• Has malaria been eradicated in the US?

  Yes
• What species of Plasmodium cause malaria?

  P. falciparum, P. vivax, P. ovale, P. malariae
• Where is malaria located?

  Tropics, 91 countries
• Does malaria only infect humans?

  Yes (P. malariae is the exception)
• What causes Trypanosomiasis?

  Trypanosoma brucei
• Trypanosomiasis?

  Transmitted by the tsetse fly

  Bite swelling, lymph node swelling, heart failure
• Where does the tsetse fly live?

  Africa
• What causes Chagas disease?

  Trypanosoma Cruzi, spread by assassin bugs
• What are reservoir animals for Chagas?

  Mammals

  Heart and blood vessel damage is common
• Is there no cure for Chagas?

  No
• What causes the plague?

  Bacterium (Y. pestis) in the lymph system
• What transmits the plague?

  Oritental rat fleas

  Humans are the primary host
• What causes the bubo that is associated with the plague?

  Expansion of the lymph nodes from when Y. pestis reaches the lymphatic system
• What is the importace of insect venom?

  Allergy testing and allergy treatment
• Apitherapy?

  Used to destroy tumor cells, anti-microbial activity

  Melittin is the major peptide in bee venom (apitoxin)

  
• Maggot Debridement Therapy?

  Remove necrotic tissue, antimicrobial, stimulates tissue growth

  Shown to be as effective as antibiotics